Synthesis of biaryls, fluorenones, cyclopenta[def]phenanthren-4-ones, and benzophenones based on formal [3+3] cyclocondensations of 1,3-bis(silyloxy)buta- 1,3-dienes with 3-(silyloxy)-2-en-1-ones

Article abstract of DOI:10.1055/s-0028-1083309

Functionalized fluorenones were efficiently prepared in four steps. The [3+3] cyclization of 1,3-bis(silyloxy)buta-1,3- dienes with 3-(silyloxy)-2-en-1- ones afforded salicylates that were transformed into their enol triflates. The Suzuki cross-coupling r

Full text of DOI:10.1055/s-0028-1083309

PAPER
445
Synthesis of Biaryls, Fluorenones, Cyclopenta[def]phenanthren-4-ones,
and Benzophenones Based on Formal [3+3] Cyclocondensations of
1,3-Bis(silyloxy)buta-1,3-dienes with 3-(Silyloxy)-2-en-1-ones
Synthesis of
B
t
iaryls,
e
Fluorenone
f
s, Cyclo
a
penta[def]p
n
henanthren-4
i
-ones,
e
and
B
enzophenon
R
es eim,a Matthias Lau,a Muhammad Adeel,a Ibrar Hussain,a Mirza A. Yawer,a Abdolmajid Riahi,a
Zafar Ahmed,a Christine Fischer,b Helmut Reinke,a Peter Langer*a,b
a
Institut für Chemie, Universität Rostock, Albert Einstein Str. 3a, 18059 Rostock, Germany
Fax +49(381)4986412; E-mail: peter.langer@uni-rostock.de
Leibniz-Institut für Katalyse an der Universität Rostock e.V., Albert Einstein Str. 29a, 18059 Rostock, Germany
b
Received 6 August 2008; revised 24 September 2008
of 2-halobiaryls.2 Valesco and Yu reported the synthesis
of fluorenones based on the reaction of malononitrile with
aromatic aldehydes and methyl ketones.11 Ciske and Jones
prepared fluorenones by Suzuki reaction of boronic acids,
Abstract: Functionalized fluorenones were efficiently prepared in
four steps. The [3+3] cyclization of 1,3-bis(silyloxy)buta-1,3-
dienes with 3-(silyloxy)-2-en-1-ones afforded salicylates that were
transformed into their enol triflates. The Suzuki cross-coupling re-
action of the latter with arylboronic acids afforded 2-(methoxycar- generated in situ from benzoic acid amides, with aryl tri-
flates and subsequent cyclization by remote metalation.12
bonyl)biaryls that were subsequently transformed into the target
molecules by intramolecular Friedel–Crafts acylation. In addition,
Fluorenones have been prepared by acid-mediated in-
1-hydroxyfluorenones were prepared by cyclization of 3-aryl-3-
tramolecular Friedel–Crafts cyclization of 2-(methoxy-
(silyloxy)-2-en-1-ones with 1,3-bis(silyloxy)buta-1,3-dienes and
carbonyl)biaryls. Recently, the synthesis of the latter by
Suzuki reactions of salicylate-derived enol triflates has
been reported.13
subsequent intramolecular Friedel–Crafts acylation of the 6-aryl-
salicylates thus formed. In this context, the synthesis of novel cyclo-
penta[def]phenanthren-4-ones is reported. In addition, the synthesis
of functionalized benzophenones is reported.
OMe
OH
OH
Key words: cyclizations, fluorenones, regioselectivity, silyl enol
ethers
HO
MeO
MeO
HO
MeO
HO
O
O
O
Fluorenones occur in a number of natural products. This
includes various highly hydroxylated derivatives, such as
dengibsin, dengibsinin, or dendroflorin (Figure 1).1 The
first two fluorenone natural products, dengibsin and den-
gibsinin, were isolated 1985 by Talapatra et al. from the
orchid Dendrobium gibsonii Lindl.1a These products were
first prepared by Sargent and co-workers.1b Fluorenones
are of considerable pharmacological relevance.2 They
have been used as probes for the redox activity of DNA.3
Amidofluorenone derivatives have been shown to be te-
lomerase inhibitors, which are important for the develop-
ment of anticancer agents.4 In addition, fluorenones
represent versatile synthetic intermediates. They have
been used, for example, during the synthesis of the anti-
biotic kinamycin D.5 Fluorenones are also important com-
pounds in photochemistry.6
OH
OH
dengibsin
dengibsinin
dendroflorin
Figure 1 Fluorenone natural products
Salicylates are available by various synthetic strategies.
An important approach to salicylates, first reported by
Chan and co-workers,14 relies on the formal [3+3] cycliza-
tion of 1,3-bis(silyloxy)buta-1,3-dienes15 with 3-(silyl-
oxy)-2-en-1-ones. In recent years, we have reported the
application of this methodology to the synthesis of a vari-
ety of functionalized arenes.16 Recently, we have
reported17 a convenient four-step synthesis of fluo-
renones: the [3+3] cyclization of 1,3-bis(silyloxy)buta-
1,3-dienes with 3-(silyloxy)-2-en-1-ones afforded salicy-
lates that were transformed into their enol triflates. The
Suzuki cross-coupling reaction of the latter with arylbo-
ronic acids afforded 2-(methoxycarbonyl)biaryls that
were subsequently transformed into the target molecules
by intramolecular Friedel–Crafts acylation. Herein, we re-
port full details of these studies. In addition, we report the
synthesis of 1-hydroxyfluorenones by cyclization of 3-
aryl-3-(silyloxy)-2-en-1-ones with 1,3-bis(silyloxy)buta-
1,3-dienes and subsequent intramolecular Friedel–Crafts
acylation of the 6-arylsalicylates thus formed.18 In this
context, the synthesis of novel cyclopenta[def]phenan-
thren-4-ones is reported. We also report the synthesis of
The most important synthetic approach to fluorenones
includes intramolecular Friedel–Crafts acylations of
appropriate biaryls.7 Other syntheses rely on [4+2] cy-
cloadditions of conjugated enynes8 and on the oxidation
of fluorenes.9 Snieckus and co-workers reported the syn-
thesis of fluorenones based on remote aromatic metala-
tion.10 Larock and co-workers reported the synthesis of
fluorenones by palladium-catalyzed cyclocarbonylation
SYNTHESIS 2009, No. 3, pp 0445–0463
x
x
.
x
x
.2
0
0
9
Advanced online publication: 09.01.2009
DOI: 10.1055/s-0028-1083309; Art ID: T13408SS
© Georg Thieme Verlag Stuttgart · New York

446
S. Reim et al.
PAPER
functionalized benzophenones based on formal [3+3] cy-
clocondensations. The advantage of the two synthetic
strategies outlined herein relies on the fact that various
substitution patterns are readily available based on a
building-block strategy. The products are not readily
available by other methods.
Me3SiO
R1
OSiMe3
OMe
OX
R3
O
R1
R2
1a,b
+
i
OMe
Me3SiO
O
R4
R2
R4
R3
1,3-Bis(silyloxy)buta-1,3-dienes 1 and 3-(silyloxy)-2-en-
1-ones 2 were prepared as previously reported.6 The tita-
nium(IV) chloride mediated [3+3] cyclocondensation of
1,3-bis(silyloxy)buta-1,3-diene 1a with 3-methyl-4-(tri-
methylsilyloxy)pent-3-en-2-one (2a), following the pro-
cedure reported by Chan,14 afforded salicylate 3a
(Scheme 1, Table 1). The cyclization presumably pro-
ceeds, following a mechanism suggested by Chan,14 by ti-
tanium(IV) chloride mediated attack of the terminal
carbon atom of 1a on to the double bond of 2a, cyclization
via the central carbon atom of the 1,3-dicarbonyl moiety,
and subsequent aromatization.
3a–h (X = H)
ii
2a–g
4a–h (X = Tf)
R6
R5
R5
iii
5a–f
B(OH)2
R5
R6
R6
R5
R5
O
R5
O
iv
R1
R2
Salicylate 3a was transformed into triflate 4a. The Suzuki
reaction of the latter with boronic acids 5a–c afforded
biaryls 6a–c. Treatment of the latter with concentrated
sulfuric acid afforded fluorenones 7a–c in high yields
(Scheme 1, Tables 1 and 2). Fluorenones 7e,f were pre-
pared based on the cyclization of 1a with 1-phenyl-3-(tri-
methylsilyloxy)but-2-en-1-one (2b). Fluorenones 7g–i
were available starting with 1a and 4-(trimethylsilyl-
oxy)pent-3-en-2-one (2c). The tetracyclic fluorenones 7j–l
were prepared from 2-[1-(trimethylsilyloxy)eth-
ylidene]cyclohexanone (2d). Fluorenones 7m–o were ob-
tained based on the cyclization of 1a with 3-ethyl-4-
(trimethylsilyloxy)pent-3-en-2-one (2e). Fluorenones 7p–
s were available based on the cyclization of 1a with 5-(tri-
methylsilyloxy)hept-4-en-3-one (2f). The cyclization of
2a with 1,3-bis(silyl enol ether) 1b, prepared from methyl
3-oxohexanoate, afforded salicylate 3g, which was trans-
formed into fluorenone 7t. The chlorinated fluorenones
7u–x were prepared based on the cyclization of 1a with 3-
chloro-4-(trimethylsilyloxy)pent-3-en-2-one (2g). The
Suzuki reactions proceeded in 44–95% yield. The forma-
tion of the fluorenones generally proceeded in very good
yields.
R1
R2
OMe
R4
R4
R3
R3
7a–c,e–x
6a–x
Scheme 1 Synthesis of fluorenones 7a–x. Reagents and conditions:
(i) TiCl4, CH2Cl2, –78 to 20 °C; (ii) Tf2O, pyridine, –78 to –10 °C; (iii)
Pd(PPh3)4 (3 mol%), K3PO4 (1.6 equiv), 1,4-dioxane, reflux, 4–20 h;
(iv) concd H2SO4, 1 h.
Table 1 Synthesis of 3 and 4
1
2
3,4 R1
R2
R3
R4
Isolated yield (%)
3
4
a
a
a
a
a
a
b
a
a
b
c
d
e
f
a
b
c
d
e
f
H
H
H
H
H
H
Et
H
Me
Me
Me
Me
Me
Et
Me
H
Me
Ph
51
55
46
32
45
44
50
62
96
69
97
97
89
89
94
98
H
Me
(CH2)4
Et
Me
Et
H
The structures of all products were established by spectro-
scopic methods. The structure of 7b was independently
confirmed by X-ray crystal structure analysis (Figure 2).19
The aryl moieties and the ester groups of 6e and 6j are
twisted out of plane, presumably due to steric or crystal
packing effects. The fluorenones are, as expected, flat
molecules. The aliphatic six-membered ring of 6j and 7l
is slightly twisted out of plane.
a
g
g
h
Me
Me
Me
Cl
Me
Me
The structures of all products were established by spectro-
scopic methods. The structure of 7ab was independently
confirmed by an X-ray crystal structure analysis
(Figure 3).19 The fluorenone is, as expected, a flat mole-
The reaction of 1,3-bis(silyl enol ethers) 1a,c–e with 3- cules. An intramolecular hydrogen bond is present.
(silyloxy)-2-en-1-ones 2h–l, prepared from aryl ketones,
The reaction of 1,3-bis(silyl enol ether) 1a with 3-(silyl-
resulted in regioselective formation of salicylates 3i–r,
oxy)-2-en-1-one 8, prepared from 2-acetyl-1-tetralone, re-
which were transformed into fluorenones 7y–ah
(Scheme 2, Table 3). The regioselective formation of 3i–
r can be explained by isomerization of 2h–l into iso-2h–l
and subsequent cyclization as described above.
sulted in regioselective formation of the known6a
dihydrophenanthrene 9 (Scheme 3).
The regioselectivity can be again explained based on tita-
nium(IV) chloride mediated isomerization of 8 into iso-8
Synthesis 2009, No. 3, 445–463 © Thieme Stuttgart · New York

PAPER
Synthesis of Biaryls, Fluorenones, Cyclopenta[def]phenanthren-4-ones, and Benzophenones
447
O
OSiMe3
Table 2 Synthesis of 6 and 7
Me3SiO
Me
O
i
6,7 R1
R2
R3
R4
R5
R6
Yielda (%)
Me
R3
R4
6
7
R3
R4
2h–l
iso-2h–l
a
b
c
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
Et
H
H
H
H
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Et
Me
Me
Me
H
Me
Me
Me
Ph
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
OMe
H
79
87
87
84
79
75
95
91
44
58
89
83
71
46
75
88
76
86
59
44
82
90
88
59
85
94
90
OSiMe3
OR2
Me3SiO
R1
Me
OMe
H
1a,c–e
b
d
e
–
OH
OH
O
O
R1
R1
H
Ph
92
80
91
85
91
61
91
89
92
91
89
92
93
80
91
92
90
89
99
99
OR2
ii
f
H
Ph
Me
OMe
H
Me
Me
g
h
i
H
Me
Me
Me
R3
R4
R3
R4
H
7y–ah
3i–r
Scheme 2 Synthesis of fluorenones 7y–ah. Reagents and condi-
tions: (i) TiCl4, CH2Cl2, –78 to 20 °C; (ii) concd H2SO4, 1 h.
H
Me
OMe
H
j
(CH2)4
Table 3 Products and Yields
k
l
(CH2)4
(CH2)4
R3
Me
OMe
H
1
2
3
7
R1
R2
R4
Yielda (%)
3
7
m
n
o
p
q
r
Et
Et
Et
H
Me
a
a
c
h
i
i
y
z
H
H
Me
Me
Me
H
H
Cl
Cl
H
H
H
H
H
F
43
40
34
37
32
35
49
32
44
44
68
83
65
75
80
60
75
51
68
76
Me
Me
Et
j
Me
H
i
k
l
aa (CH2)5Me Me
H
a
d
e
j
ab
H
Me
Me
Et
Cl
Cl
Cl
F
Et
H
Et
Me
OMe
j
m
n
o
p
q
r
ac Me
ad Et
Et
H
Et
j
s
Et
H
Et
OMe OMe
a
d
a
e
k
k
l
ae
af
H
Me
Me
Me
Et
t
Me
Me
Me
Me
Me
Me
Cl
Cl
Cl
Cl
Me
Me
Me
Me
Me
H
H
H
H
H
OMe
OMe
Cl
Me
H
F
u
v
w
x
ag
H
l
ah Et
H
F
CF3
H
a Yields of isolated products.
a Yields of isolated products.
b Experiment was not performed.
Figure 2 ORTEP plot of 7b (50% probability level)
Figure 3 ORTEP plot of 7ab (50% probability level)
Synthesis 2009, No. 3, 445–463 © Thieme Stuttgart · New York

448
S. Reim et al.
PAPER
(silyloxy)-2-en-1-ones 15a and 15b afforded the function-
alized benzophenones 16a and 16b, respectively
(Scheme 4).
O
OSiMe3
Me3SiO
Me
O
i
Me
In conclusion, two methods for the synthesis of function-
alized fluorenones were developed. The first approach re-
lies on the [3+3] cyclization of 1,3-bis(silyloxy)buta-1,3-
dienes with 3-(silyloxy)-2-en-1-ones to give salicylates.
Suzuki cross-coupling reactions of the salicylate-derived
enol triflates afforded 2-(methoxycarbonyl)biaryls that
were subsequently transformed into the target molecules
by intramolecular Friedel–Crafts acylation. The second
approach allows a convenient synthesis of 1-hydroxy-
fluorenones. The cyclization of 3-aryl-3-(silyloxy)-2-en-
1-ones with 1,3-bis(silyloxy)buta-1,3-dienes afforded 6-
arylsalicylates that were subsequently transformed into
the products by intramolecular Friedel–Crafts acylation.
In this context, the synthesis of novel cyclopen-
ta[def]phenanthren-4-ones is reported. The synthesis of
functionalized benzophenones has also been reported.
The advantage of the synthetic strategies outlined herein
relies on the fact that various substitution patterns are
readily available based on a building-block strategy. The
products are not readily available by other methods.
iso-8
8
OSiMe3
Me3SiO
OMe
OH
1a
O
OH
O
OMe
ii
Me
Me
9 (41%)
11 (40%)
iii
iii
OH
O
OH
O
ii
OMe
Me
Me
All solvents were dried by standard methods and all reactions were
carried out under an inert atmosphere. For 1H and 13C NMR spectra
the deuterated solvents indicated were used. MS data were obtained
by electron ionization (EI, 70 eV), chemical ionization (CI, isobu-
tane), or electrospray ionization (ESI). For preparative scale chro-
matography silica gel 60 (0.063–0.200 mm, 70–230 mesh) was
used.
12 (27%)
10 (57%)
Scheme
3
Synthesis of cyclopenta[def]phenanthren-4-one 12.
Reagents and conditions: (i) TiCl4, CH2Cl2, –78 to 20 °C; (ii) H2SO4,
1 h; (iii) DDQ (2.0 equiv), 1,4-dioxane, reflux, 48 h.
and subsequent cyclization. Treatment of 9 with concen-
trated sulfuric acid afforded product 11, which was trans-
formed into cyclopenta[def]phenanthren-4-one 12 by
Salicylates 3 and 9; General Procedure
To a CH2Cl2 soln of 3-(silyloxy)-2-en-1-ones 2a–k or 8 (1.0 equiv)
oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquin- and 1,3-bis(silyl enol ethers) 1a–c (1.0 equiv) was added dropwise,
one (Scheme 3).16 The oxidation of 9 afforded the phenan-
threne 10. All attempts to transform 10 into 12 proved to
be unsuccessful, presumably due to the rigid character of
10.
at –78 °C, TiCl4 (1.0 equiv) under an argon atmosphere. The mix-
ture was stirred at –78 °C for 30 min and was then allowed to warm
to 20 °C over 18 h. To the mixture was added aq 10% HCl, the or-
ganic layer was separated, and the aqueous layer was repeatedly ex-
tracted with CH2Cl2. The combined organic extracts were dried
(Na2SO4) and filtered. The filtrate was concentrated in vacuo and
the residue was purified by chromatography (silica gel, n-heptane–
EtOAc) to give salicylates 3 or 9.
To the best of our knowledge, the synthesis of functional-
ized benzophenones based on formal [3+3] cycloconden-
sations has not been reported to date. The reaction of the
novel 1,3-bis(trimethylsilyloxy)buta-1,3-diene 14 with 3-
Methyl 6-Hydroxy-2,3,4-trimethylbenzoate (3a)
Starting with 1a (1.042 g, 4.0 mmol), 2a (0.745 g, 4.0 mmol), and
O
OSiMe3
Ph
OH
O
OMe
TiCl4 (0.40 mL, 4.0 mmol) in CH2Cl2 (8 mL), 3a was isolated after
column chromatography (silica gel, n-heptane–EtOAc, 20:1) as a
colorless solid; yield: 0.395 g (51%); mp 54–55 °C.
Me
15a
IR (Nujol): 1665 (s), 1598 (w), 1577 (w), 1346 (m), 1313 (s), 1234
(s), 1207 (s), 1155 (m), 1065 (w), 1006 cm–1 (w).
1H NMR (250 MHz, CDCl3): d = 2.12 (s, 3 H, CH3), 2.26 (s, 3 H,
CH3), 2.43 (s, 3 H, CH3), 3.94 (s, 3 H, OCH3), 6.68 (s, 1 H, CH),
10.48 (s, 1 H, OH).
13C NMR (63 MHz, CDCl3): d = 15.3, 19.0, 21.6 (CH3), 51.9
(OCH3), 111.4 (C), 116.2 (CH), 127.3, 138.2, 143.9 (C), 159.1
(COH), 172.0 (CO2Me).
Me
Ph
Me3SiO
OSiMe3
i
i
16a (30%)
MeO
14
OH
O
OMe
O
OSiMe3
Me
Me
Me
Me
Me
16b (38%)
Me
15b
MS (CI, isobutane): m/z (%) = 195 ([M + 1]+, 100).
Anal. Calcd for C11H14O3 (194.23): C, 68.02; H, 7.27. Found: C,
67.95; H, 7.27.
Scheme 4 Synthesis of benzophenones 16a,b. Reagents and condi-
tions: (i) TiCl4, CH2Cl2, –78 to 20 °C; (ii) concd H2SO4, 1 h.
Synthesis 2009, No. 3, 445–463 © Thieme Stuttgart · New York

PAPER
Synthesis of Biaryls, Fluorenones, Cyclopenta[def]phenanthren-4-ones, and Benzophenones
449
Methyl 3-Hydroxy-5-methylbiphenyl-2-carboxylate (3b)
Starting with 1a (2.605 g, 10.0 mmol), 2b (2.344 g, 10.0 mmol),
and TiCl4 (1.10 mL, 10.0 mmol) in CH2Cl2 (20 mL), 3b was isolat-
ed after column chromatography (silica gel, n-heptane–EtOAc,
20:1) as a colorless oil; yield: 1.333 g (55%). A small amount of
starting material could not be separated.
1H NMR (300 MHz, CDCl3): d = 1.07 (t, J = 7.2 Hz, 3 H, CH3),
2.47 (s, 3 H, CH3), 2.61 (s, 3 H, CH3), 2.63 (q, J = 7.1 Hz, 2 H,
CH2), 3.94 (s, 3 H, OCH3), 6.68 (s, 1 H, CH), 10.54 (s, 1 H, OH).
13C NMR (75 MHz, CDCl3): d = 13.7, 18.1, 20.7 (CH3), 22.3 (CH2),
51.9 (OCH3), 111.6 (C), 116.8 (CH), 133.3, 137.8, 143.6 (C), 159.3
(COH), 172.1 (CO2Me).
IR (Nujol): 1657 (s), 1611 (s), 1572 (m), 1359 (s), 1325 (s), 1272
(s), 1217 (s), 1165 (m), 1142 (w), 1100 (m), 1030 (w), 1010 cm–1
(w).
1H NMR (250 MHz, CDCl3): d = 2.33 (s, 3 H, CH3), 3.46 (s, 3 H,
OCH3), 6.61–6.62 (m, 1 H, CH), 6.81–6.82 (m, 1 H, CH), 7.19–7.22
(m, 2 H, CH), 7.29–7.35 (m, 3 H, CH), 10.76 (s, 1 H, OH).
13C NMR (75 MHz, CDCl3): d = 21.6 (CH3), 51.5 (OCH3), 109.3
(C), 116.9, 124.0, 126.7, 127.0, 127.5, 128.1, 128.6 (CH), 142.9,
144.7, 144.8 (C), 161.7 (COH), 171.0 (CO2Me).
MS (EI, 70 eV): m/z (%) = 208 (M+, 16), 176 (53), 161 (53), 28
(100).
Anal. Calcd for C12H16O3 (208.25): C, 69.21; H, 7.74. Found: C,
68.9; H, 7.77.
Methyl 2,4-Diethyl-6-hydroxybenzoate (3f)
Starting with 1a (2.605 g, 10.0 mmol), 2f (2.004 g, 10.0 mmol), and
TiCl4 (1.10 mL, 10.0 mmol) in CH2Cl2 (20 mL), 3f was isolated af-
ter column chromatography (silica gel, n-heptane–EtOAc, 20:1) as
a colorless oil; yield: 0.911 g (44%).
MS (EI, 70 eV): m/z (%) = 242 (M+, 29), 211 (15), 210 (100), 182
(35).
IR (neat): 3408 (br, w), 2969 (m), 2936 (m), 2877 (w), 1661 (s),
1617 (m), 1570 (m), 1438 (m), 1361 (m), 1323 cm–1 (m).
Methyl 2-Hydroxy-4,6-dimethylbenzoate (3c)
3
1H NMR (250 MHz, CDCl3): d = 1.18 (t, J = 7.3 Hz, 3 H, CH3),
Starting with 1a (2.605 g, 10.0 mmol), 2c (1.723 g, 10.0 mmol),
and TiCl4 (1.10 mL, 10.0 mmol) in CH2Cl2 (20 mL), 3c was isolat-
ed after column chromatography (silica gel, n-heptane–EtOAc,
20:1) as a colorless solid; yield: 0.825 g (46%); mp 41–43 °C.
1.21 (t, 3J = 7.6 Hz, 3 H, CH3), 2.57 (q, 3J = 7.6 Hz, 2 H, CH2), 2.90
(q, 3J = 7.3 Hz, 2 H, CH2), 3.94 (s, 3 H, OCH3), 6.58 (d, 4J = 1.8 Hz,
1 H, CH), 6.69 (d, 4J = 1.8 Hz, 1 H, CH), 11.24 (s, 1 H, OH).
13C NMR (75 MHz, CDCl3): d = 14.6, 16.1 (CH3), 28.8, 29.6
(CH2), 51.9 (OCH3), 114.5, 121.8 (CH), 109.1, 147.3, 151.5 (C),
162.9 (COH), 172.0 (CO2Me).
IR (Nujol): 1664 (s), 1625 (w), 1573 (w), 1316 (m), 1262 (s), 1212
(s), 1165 (w), 1100 (m), 1062 (w), 1035 cm–1 (w).
1H NMR (250 MHz, CDCl3): d = 2.26 (s, 3 H, CH3), 2.49 (s, 3 H,
CH3), 3.93 (s, 3 H, OCH3), 6.53 (s, 1 H, CH), 6.65 (s, 1 H, CH),
11.32 (s, 1 H, OH).
13C NMR (75 MHz, CDCl3): d = 21.5, 23.9 (CH3), 51.9 (OCH3),
109.6 (C), 115.8, 124.2 (CH), 141.0, 145.3 (C), 163.0 (COH), 172.2
(CO2Me).
MS (EI, 70 eV): m/z (%) = 208 (M+, 23), 177 (15), 176 (100), 133
(26).
Anal. Calcd for C12H16O3 (208.25): C, 69.21; H, 7.74. Found: C,
68.93; H, 7.83.
Methyl 3-Ethyl-2-hydroxy-4,5,6-trimethylbenzoate (3g)
Starting with 1b (2.885 g, 10.0 mmol), 2a (1.863 g, 10.0 mmol),
and TiCl4 (1.10 mL, 10.0 mmol) in CH2Cl2 (20 mL), 3g was isolat-
ed after column chromatography (silica gel, n-heptane–EtOAc,
20:1) as a yellow oil; yield: 1.073 g (50%).
MS (EI, 70 eV): m/z (%) = 180 (M+, 36), 149 (34), 148 (100), 120
(35), 91 (36).
Anal. Calcd for C10H12O3 (180.20): C, 66.65; H, 6.71. Found: C,
66.49; H, 6.72.
IR (Nujol): 1733 (w), 1718 (w), 1657 (s), 1599 (s), 1570 (m), 1355
(s), 1318 (s), 1273 (s), 1241 (m), 1203 cm–1 (s).
Methyl 2-Hydroxy-4-methyl-5,6,7,8-tetrahydronaphthalene-1-
carboxylate (3d)
Starting with 1a (1.302 g, 5.0 mmol), 2d (1.062 g, 5.0 mmol), and
TiCl4 (0.60 mL, 5.0 mmol) in CH2Cl2 (10 mL), 3d was isolated af-
ter column chromatography (silica gel, n-heptane–EtOAc, 20:1) as
a colorless solid; yield: 0.352 g (32%).
3
1H NMR (250 MHz, CDCl3): d = 1.10 (t, J = 7.5 Hz, 3 H, CH3),
2.15 (s, 3 H, CH3), 2.26 (s, 3 H, CH3), 2.40 (s, 3 H, CH3), 2.73 (q,
3J = 7.5 Hz, 2 H, CH2), 3.93 (s, 3 H, OCH3), 10.67 (s, 1 H, OH).
13C NMR (75 MHz, CDCl3): d = 13.6, 16.1, 16.6, 19.2 (CH3), 19.8
(CH2), 52.0 (OCH3), 111.2, 127.1, 128.1, 134.8, 141.5 (C), 156.8
(COH), 172.7 (CO2Me).
MS (EI, 70 eV): m/z (%) = 222 (M+, 36), 191 (21), 190 (90), 162
(100), 147 (24).
HRMS (EI): m/z [M]+ calcd for C13H18O3: 222.12505; found:
222.12559.
IR (KBr): 3429 (m), 2929 (s), 1657 (s), 1608 (s), 1443 (s), 1318 (s),
1234 (s), 1075 cm–1 (m).
1H NMR (300 MHz, CDCl3): d = 1.66–1.80 (m, 4 H, CH2), 2.19 (s,
3 H, CH3), 2.57 (m, 2 H, CH2), 2.98 (t, J = 6.3 Hz, 2 H, CH2), 3.93
(s, 3 H, OCH3), 6.69 (s, 1 H, CH), 10.84 (s, 1 H, OH).
13C NMR (75 MHz, CDCl3): d = 20.4 (CH3), 22.5, 23.1, 27.0, 30.2
[(CH2)4], 51.9 (OCH3), 110.4 (C), 116.5 (CH), 127.7, 139.3, 144.7
(C), 159.9 (COH), 172.2 (CO2Me).
Methyl 3-Chloro-6-hydroxy-2,4-dimethylbenzoate (3h)
Starting with 1a (1.980 g, 7.6 mmol), 2g (1.571 g, 7.6 mmol), and
TiCl4 (0.80 mL, 7.6 mmol) in CH2Cl2 (15 mL), 3h was isolated as a
colorless solid; yield: 1.010 g (62%); mp 59–60 °C.
MS (EI, 70 eV): m/z (%) = 220 (M+, 22), 189 (16), 188 (100), 160
(16), 132 (13), 28 (67).
Anal. Calcd for C13H16O3 (220.26): C, 70.89; H, 7.32. Found: C,
70.87; H, 7.35.
IR (KBr): 3426 (w), 3000 (w), 2952 (s), 2874 (m), 1663 (s), 1603
(s), 1564 (s), 1449 (s), 1381 (m), 1358 (s), 1310 (s), 1229 (s), 1190
(s), 1104 cm–1 (m).
Methyl 3-Ethyl-6-hydroxy-2,4-dimethylbenzoate (3e)
Starting with 1a (0.521 g, 2.0 mmol), 2e (0.401 g, 2.0 mmol), and
TiCl4 (0.20 mL, 2.0 mmol) in CH2Cl2 (4 mL), 3e was isolated after
column chromatography (silica gel, n-heptane–EtOAc, 20:1) as a
colorless solid; yield: 0.186 g (45%).
1H NMR (250 MHz, CDCl3): d = 2.35 (s, 3 H, CH3), 2.60 (s, 3 H,
CH3), 3.96 (s, 3 H, OCH3), 6.76 (s, 1 H, CH), 10.83 (s, 1 H, OH).
13C NMR (75 MHz, CDCl3): d = 19.9, 21.9 (CH3), 52.3 (OCH3),
111.9 (C), 117.4 (CH), 126.8, 137.9, 143.6 (C), 159.9 (COH), 171.3
(CO2Me).
IR (KBr): 3022 (m), 2969 (s), 1661 (s), 1445 (s), 1354 (s), 1228 (s),
1156 (s), 1074 cm–1 (s).
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450
S. Reim et al.
PAPER
MS (EI, 70 eV): m/z (%) = 214 (M+, 35Cl, 88), 184 (100), 154 (60),
HRMS (EI): m/z (M+, 35Cl) calcd for C21H25ClO3: 360.14867;
91 (64).
found: 360.147678.
Anal. Calcd for C10H11ClO3 (214.65): C, 55.96; H, 5.17. Found: C,
55.97; H, 5.17.
Methyl 2¢-Chloro-3-hydroxy-5-methylbiphenyl-2-carboxylate
(3l)
Starting with 1a (0.537 g, 2.2 mmol), 2j (0.591 g, 2.2 mmol), and
TiCl4 (0.20 mL, 2.2 mmol) in CH2Cl2 (4 mL), 3l was isolated as a
colorless solid; yield: 0.226 g (37%).
Methyl 3-Hydroxy-2¢,5-dimethylbiphenyl-2-carboxylate (3i)
Starting with 1a (0.287 g, 1.1 mmol), 2i (0.273 g, 1.1 mmol), and
TiCl4 (0.10 mL, 1.1 mmol) in CH2Cl2 (2 mL), 3i was isolated as a
yellow oil; yield: 0.120 g (43%).
IR (neat): 3070 (w), 3017 (w), 2952 (m), 2857 (w), 1660 (s), 1612
(m), 1572 (m), 1433 (m), 1353 (m), 1259 (s), 1215 (s), 1123 (m),
1013 cm–1 (s).
1H NMR (300 MHz, CDCl3): d = 2.24 (s, 3 H, CH3), 3.39 (s, 3 H,
OCH3), 6.42 (s, 1 H, CH), 6.77 (s, 1 H, CH), 7.08–7.11 (m, 1 H,
CH), 7.14–7.20 (m, 2 H, CH), 7.26–7.29 (m, 1 H, CH), 11.05 (s, 1
H, OH).
13C NMR (75 MHz, CDCl3): d = 20.6 (CH3), 50.8 (OCH3), 108.4
(C), 116.7, 122.6, 125.8, 127.5, 128.9, 130.6 (CH), 134.5, 140.3,
140.7, 144.3 (C), 160.9 (COH), 169.9 (CO2Me).
IR (neat): 3069 (w), 3015 (w), 2954 (m), 2853 (w), 1661 (s), 1612
(m), 1572 (m), 1438 (m), 1353 (m), 1259 (s), 1215 (s), 1123 (m),
1013 cm–1 (s).
1H NMR (300 MHz, CDCl3): d = 2.03 (s, 3 H, CH3), 2.33 (s, 3 H,
CH3), 3.43 (s, 3 H, OCH3), 6.50 (s, 1 H, CH), 6.82 (s, 1 H, CH),
6.99–7.02 (m, 1 H, CH), 7.15–7.20 (m, 3 H, CH), 11.11 (s, 1 H,
OH).
13C NMR (75 MHz, CDCl3): d = 18.8, 20.6 (CH3), 50.6 (OCH3),
108.3 (C), 115.8, 122.5, 123.9, 125.7, 128.4, 132.3 (CH), 133.7,
141.7, 143.2, 144.2 (C), 161.0 (COH), 170.3 (CO2Me).
MS (EI, 70 eV): m/z (%) = 276 (M+, 35Cl, 30), 241 (100), 152 (21).
MS (EI, 70 eV): m/z (%) = 256 (M+, 28), 225 (19), 224 (100), 181
HRMS (EI): m/z (M+, 35Cl) calcd for C15H13ClO3: 276.05477;
(19), 153 (26).
found: 276.054962.
HRMS (EI): m/z [M]+ calcd for C16H16O3: 256.10940; found:
256.110114.
Methyl 2¢-Chloro-3-hydroxy-4,5-dimethylbiphenyl-2-carboxy-
late (3m)
Starting with 1d (0.603 g, 2.2 mmol), 2j (0.535 g, 2.2 mmol), and
TiCl4 (0.417 g, 2.2 mmol) in CH2Cl2 (4 mL), 3m was isolated;
yield: 0.190 g (32%).
Methyl 4¢-Chloro-3-hydroxy-5-methylbiphenyl-2-carboxylate
(3j)
Starting with 1a (0.573 g, 2.2 mmol), 2i (0.591 g, 2.2 mmol), and
TiCl4 (0.20 mL, 2.2 mmol) in CH2Cl2 (4 mL), 3j was isolated as a
colorless solid; yield: 0.242 g (40%); mp 94–96 °C.
IR (KBr): 2958 (s), 2870 (m), 1655 (s), 1616 (m), 1503 (m), 1468
(m), 1415 (m), 1399 (m), 1246 (s), 1233 (s), 1097 cm–1 (m).
IR (neat): 3060 (w), 3020 (w), 2960 (m), 2848 (w), 1664 (s), 1612
(m), 1572 (m), 1438 (m), 1353 (m), 1259 (s), 1215 (s), 1123 (m),
1013 cm–1 (s).
1H NMR (300 MHz, CDCl3): d = 2.33 (s, 3 H, CH3), 3.50 (s, 3 H,
OCH3), 6.56 (br s, 1 H, CH), 6.82 (br s, 1 H, CH), 7.11–7.16 (m, 2
H, CH), 7.29–7.34 (m, 2 H, CH), 10.83 (s, 1 H, OH).
13C NMR (75 MHz, CDCl3): d = 21.6 (CH3), 51.6 (OCH3), 109.0
(C), 117.3, 123.9, 127.7, 129.4 (CH), 132.7, 141.4, 143.4, 145.0
(C), 161.9 (COH), 171.1 (CO2Me).
1H NMR (300 MHz, CDCl3): d = 2.13 (s, 3 H, CH3), 2.20 (s, 3 H,
CH3), 3.38 (s, 3 H, OCH3), 6.42 (s, 1 H, CH), 7.06–7.10 (m, 1 H,
CH), 7.12–7.16 (m, 2 H, CH), 7.25–7.28 (m, 1 H, CH), 11.34 (s, 1
H, OH).
13C NMR (75 MHz, CDCl3): d = 11.9, 20.9 (CH3), 52.5 (OCH3),
109.5 (C), 124.1 (CH), 125.1 (C), 126.6, 128.3, 128.9, 130.2 (CH),
133.1, 138.5, 142.4, 143.8 (C), 160.3 (COH), 171.9 (CO2Me).
GC-MS (EI, 70 eV): m/z (%) = 290 (M+, 35Cl, 9), 255 (57), 240 (5),
223 (100), 195 (9), 165 (18), 152 (14), 128 (6).
MS (EI, 70 eV): m/z (%) = 276 (M+, 35Cl, 30), 244 (100), 216 (26),
HRMS (EI): m/z (M+, 35Cl) calcd for C16H15ClO3: 290.07042;
152 (27).
found: 290.07117.
HRMS (EI): m/z (M+, 35Cl) calcd for C15H13ClO3: 276.05477;
found: 276.05567.
Ethyl 2¢-Chloro-4-ethyl-3-hydroxy-5-methylbiphenyl-2-car-
boxylate (3n)
Starting with 1e (0.651 g, 2.2 mmol), 2j (0.535 g, 2.2 mmol), and
TiCl4 (0.417 g, 2.2 mmol) in CH2Cl2 (4 mL), 3n was isolated; yield:
0.224 g (35%).
1H NMR (300 MHz, CDCl3): d = 0.66 (t, 3J = 7.5 Hz, 3 H,
CH2CH3), 1.08 (t, 3J = 7.4 Hz, 3 H, OCH2CH3), 2.23 (s, 3 H, CH3),
2.58–2.79 (m, 2 H, CH2CH3), 3.81–3.91 (m, 2 H, OCH2CH3), 6.40
(s, 1 H, CH), 7.07–7.10 (m, 1 H, CH), 7.11–7.15 (m, 2 H, CH),
7.24–7.27 (m, 1 H, CH), 11.47 (s, 1 H, OH).
13C NMR (75 MHz, CDCl3): d = 12.0 (CH2CH3), 18.4 (OCH2CH3),
18.5 (CH3), 18.6 (CH2CH3), 59.8 (OCH2CH3), 108.3 (C), 122.8,
126.7, 127.4, 128.8, 129.5 (CH), 131.9, 137.3, 141.4, 141.5 (C),
158.9 (COH), 170.0 (CO2Et).
Methyl 4¢-Chloro-4-hexyl-3-hydroxy-5-methylbiphenyl-2-car-
boxylate (3k)
Starting with 1c (0.758 g, 2.2 mmol), 2i (0.591 g, 2.2 mmol), and
TiCl4 (0.20 mL, 2.2 mmol) in CH2Cl2 (4 mL), 3k was isolated as a
yellow oil; yield: 0.273 g (34%).
IR (neat): 3074 (w), 3022 (w), 2955 (m), 2860 (w), 1665 (s), 1617
(m), 1568 (m), 1429 (m), 1353 (m), 1259 (s), 1215 (s), 1123 (m),
1013 cm–1 (s).
1H NMR (250 MHz, CDCl3): d = 0.76–0.82 (m, 3 H, CH3), 1.19 [m,
8 H, (CH2)4], 2.04 (s, 3 H, CH3), 3.43 (m, 2 H, CH2), 3.63 (s, 3 H,
OCH3), 6.72 (s, 1 H, CH), 7.34 (d, J = 8.6 Hz, 2 H, CH), 7.76 (d,
J = 8.6 Hz, 2 H, CH), 11.00 (s, 1 H, OH).
13C NMR (62 MHz, CDCl3): d = 14.0, 17.6 (CH3), 19.2, 27.3, 28.8,
31.7, 48.1 (CH2), 52.3 (OCH3), 124.2, 128.7, 128.9 (CH), 137.2,
139.1, 154.5, 166.9, 189.6 (C), 200.8 (CO2Me).
GC-MS (EI, 70 eV): m/z (%) = 318 (M+, 35Cl, 10), 283 (50), 272
(11), 255 (17), 237 (100), 165 (21), 152 (6).
HRMS (EI): m/z (M+, 35Cl) calcd for C18H19ClO3: 318.10172;
found: 318.102.
MS (EI, 70 eV): m/z (%) = 360 (M+, 35Cl, 49), 311 (28), 257 (68),
223 (100), 165 (46).
Synthesis 2009, No. 3, 445–463 © Thieme Stuttgart · New York

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Synthesis of Biaryls, Fluorenones, Cyclopenta[def]phenanthren-4-ones, and Benzophenones
451
Methyl 2¢-Fluoro-3-hydroxy-5-methylbiphenyl-2-carboxylate
(3o)
Starting with 1a (0.286 g, 1.1 mmol), 2k (0.252 g, 1.0 mmol), and
TiCl4 (0.120 mL, 1.1 mmol) in CH2Cl2 (2 mL), 3o was isolated as a
yellowish oil; yield: 0.127 g (49%).
1H NMR (300 MHz, CDCl3): d = 0.73 (t, 3J = 7.2 Hz, 3 H,
CH2CH3), 1.09 (t, 3J = 7.4 Hz, 3 H, OCH2CH3), 2.25 (s, 3 H, CH3),
2.66 (q, 3J = 7.4 Hz, 2 H, CH2CH3), 3.91 (q, 3J = 7.3 Hz, 2 H,
OCH2CH3), 6.49 (s, 1 H, CHAr), 6.91–6.97 (m, 2 H, CHAr), 7.08–
7.11 (m, 2 H, CHAr), 11.14 (s, 1 H, OH).
IR (neat): 3060 (w), 3025 (w), 2960 (m), 2851 (w), 1653 (s), 1612
(m), 1572 (m), 1438 (m), 1353 (m), 1259 (s), 1215 (s), 1112 (m),
1013 (s), 848 (m), 722 (s), 697 (s), 626 cm–1 (w).
1H NMR (300 MHz, CDCl3): d = 2.24 (s, 3 H, CH3), 3.43 (s, 3 H,
OCH3), 6.50 (s, 1 H, ArH), 6.76 (s, 1 H, ArH), 6.91–6.97 (m, 1 H,
ArH), 7.03–7.21 (m, 3 H, ArH), 10.93 (s, 1 H, OH).
13C NMR (75 MHz, CDCl3): d = 12.0 (CH2CH3), 18.4 (OCH2CH3),
18.5 (CH3), 28.6 (CH2CH3), 59.8 (OCH2CH3), 108.3 (C), 113.2,
123.2 (CH), 128.7 (C), 129.0 (CH), 136.6, 138.4, 141.1 (C), 158.7
(COH), 160.8 (d, 1J = 244.0 Hz, CF), 170.3 (CO2Et).
GC-MS (EI, 70 eV): m/z (%) = 302 (M+, 53), 256 (73), 241 (100),
223 (10), 213 (57), 199 (8), 183 (29).
13C NMR (75 MHz, CDCl3): d = 22.0 (CH3), 52.1 (OCH3), 110.1
(C), 114.7, 118.2, 124.0, 124.6, 129.1, 130.4 (CH), 138.1, 145.6,
158.1, 161.3, 162.3 (C), 171.4 (C=O).
HRMS (EI): m/z [M]+ calcd for C18H19FO3: 302.13127; found:
302.13190.
Methyl 3-Hydroxy-1-methyl-9,10-dihydrophenanthrene-4-car-
boxylate (9)
Starting with 1a (2.605 g, 10.0 mmol), 8 (1.302 g, 5.0 mmol), and
TiCl4 (0.60 mL, 5.0 mmol) in CH2Cl2 (10 mL), 9 was isolated after
column chromatography (silica gel, n-heptane–EtOAc, 9:1) as a
yellow oil; yield: 0.549 g (41%).
MS (EI, 70 eV): m/z (%) = 260 (M+, 37), 229 (18), 228 (100), 200
(42), 171 (17), 151 (3).
HRMS (EI): m/z [M]+ calcd for C15H13FO3: 260.08432; found:
260.083875.
Methyl 2¢-Fluoro-3-hydroxy-4,5-dimethylbiphenyl-2-carboxy-
late (3p)
Starting with 1d (0.452 g, 1.6 mmol), 2k (0.412 g, 1.5 mmol), and
TiCl4 (0.313 g, 1.6 mmol) in CH2Cl2 (3 mL), 3p was isolated as a
yellow solid; yield: 0.150 g (32%).
1H NMR (300 MHz, CDCl3): d = 2.13 (s, 3 H, CH3), 2.21 (s, 3 H,
CH3), 3.43 (s, 3 H, OCH3), 6.51 (s, 1 H, CH), 6.90–6.96 (m, 1 H,
CH), 7.04–7.07 (m, 1 H, CH), 7.11–7.22 (m, 2 H, CH), 11.27 (s, 1
H, OH).
13C NMR (75 MHz, CDCl3): d = 11.5, 20.4 (CH3), 51.7 (OCH3),
109.3 (C), 114.4, 123.6, 124.3 (CH), 124.8 (C), 128.6, 130.1 (CH),
130.8, 134.4, 143.4 (C), 159.7 (d, 1J = 240.9 Hz, CF), 159.9 (COH),
171.6 (CO2Me).
IR (neat): 3330 (w), 3278 (w), 3067 (w), 3021 (w), 2949 (m), 2896
(w), 2840 (w), 1731 (w), 1666 (s), 1605 (m), 1572 (s), 1492 (m),
1435 (s), 1317 (s), 1236 (s), 1209 (s), 1128 (m), 1066 cm–1 (s).
1H NMR (250 MHz, CDCl3): d = 2.31 (s, 3 H, CH3), 2.57–2.62 (m,
2 H, CH2), 2.78–2.83 (m, 2 H, CH2), 3.64 (s, 3 H, OCH3), 6.79 (s, 1
H, CH), 7.04–7.08 (m, 1 H, CH), 7.16–7.24 (m, 2 H, CH), 7.26–7.28
(m, 1 H, CH), 9.53 (s, 1 H, OH).
13C NMR (75 MHz, CDCl3): d = 20.3 (CH3), 24.8, 29.1 (CH2), 51.6
(OCH3), 109.2 (C), 117.5, 125.4, 127.1, 127.3, 129.0 (CH), 130.6,
134.4, 136.6, 137.9, 141.9 (C), 158.1 (COH), 172.0 (C=O).
MS (EI, 70 eV): m/z (%) = 268 (M+, 35), 237 (21), 236 (100), 208
(19), 165 (32).
GC-MS (EI, 70 eV): m/z (%) = 274 (M+, 45), 242 (100), 227 (58),
213 (10), 199 (59), 183 (12), 170 (16).
Anal. Calcd for C17H16O3 (268.31): C, 76.10; H, 6.01. Found: C,
76.36; H, 6.05.
HRMS (EI): m/z [M]+ calcd for C16H15FO3: 274.09997; found:
274.09978.
Triflates 4; General Procedure
To a soln of 3a–h (1.0 equiv) in CH2Cl2 (10 mL/mmol) was added
pyridine (2.0 equiv) at –78 °C under an argon atmosphere. After
10 min, Tf2O (1.2 equiv) was added at –78 °C. The mixture was al-
lowed to warm up to 0 °C and stirred for 4 h. The products were iso-
lated by column chromatography (silica gel; CH2Cl2).
Methyl 4¢-Fluoro-3-hydroxy-5-methylbiphenyl-2-carboxylate
(3q)
Starting with 1a (0.378 g, 1.5 mmol), 2l (0.429 g, 1.6 mmol), and
TiCl4 (0.312 g, 1.6 mmol) in CH2Cl2 (3 mL), 3q was isolated as a
colorless oil; yield: 0.168 g (44%).
Methyl 2,3,4-Trimethyl-6-(trifluoromethylsulfonyloxy)ben-
zoate (4a)
Starting with 3a (0.833 g, 4.3 mmol), pyridine (0.70 mL,
8.6 mmol), and Tf2O (0.90 mL, 5.1 mmol) in CH2Cl2 (43 mL), 4a
was isolated as a colorless oil; yield: 1.342 g (96%).
1H NMR (500 MHz, CDCl3): d = 2.19 (s, 3 H, CH3), 2.29 (s, 3 H,
CH3), 2.32 (s, 3 H, CH3), 3.93 (s, 3 H, OCH3), 6.96 (s, 1 H, CH).
13C NMR (126 MHz, CDCl3): d = 15.5, 17.6, 21.0 (CH3), 52.5
(OCH3), 118.5 (q, 1JC,F = 320.5 Hz, CF3), 120.0 (CH), 125.3, 136.4,
136.8, 140.4, 143.8 (C), 166.2 (CO2Me).
MS (EI, 70 eV): m/z (%) = 326 (M+, 51), 295 (39), 193 (100), 162
(37), 161 (36), 133 (41).
IR (KBr): 2948 (s), 2895 (m), 1675 (s), 1616 (m), 1493 (m), 1458
(m), 1405 (m), 1399 (m), 1254 (s), 1219 (s), 1068 (m), 748 cm–1 (s).
1H NMR (300 MHz, CDCl3): d = 2.25 (s, 3 H, CH3), 3.41 (s, 3 H,
OCH3), 6.49 (s, 1 H, CH), 6.74 (s, 1 H, CH), 6.92–9.98 (m, 2 H,
CH), 6.83 (s, 2 H, CH), 10.74 (s, 1 H, OH).
13C NMR (75 MHz, CDCl3): d = 20.5 (CH3), 50.5 (OCH3), 108.2
(C), 113.4, 116.1, 123.0, 128.5 (CH), 137.8, 142.5, 143.9 (C), 160.9
(d, 1J = 219.5 Hz, CF), 162.5 (COH), 170.2 (CO2Me).
GC-MS (EI, 70 eV): m/z (%) = 260 (M+, 34), 228 (100), 200 (46),
171 (21), 157 (6), 146 (4).
HRMS (EI): m/z [M]+ calcd for C15H13FO3: 260.08432; found:
260.08383.
Methyl 5-Methyl-3-(trifluoromethylsulfonyloxy)biphenyl-2-
carboxylate (4b)
Starting with 3b (0.700 g, 2.9 mmol), pyridine (0.50 mL,
5.8 mmol), and Tf2O (0.60 mL, 3.5 mmol) in CH2Cl2 (29 mL), 4b
was isolated as a colorless solid; yield: 0.749 g (69%).
1H NMR (250 MHz, CDCl3): d = 2.45 (s, 3 H, CH3), 3.66 (s, 3 H,
OCH3), 7.13 (s, 1 H, CH), 7.23 (m, 1 H, CH), 7.31–7.36 (m, 2 H,
CH), 7.36–7.39 (m, 2 H, CH), 7.40–7.44 (m, 1 H, CH).
Ethyl 4-Ethyl-4¢-fluoro-3-hydroxy-5-methylbiphenyl-2-carbox-
ylate (3r)
Starting with 1e (0.378 g, 1.5 mmol), 2l (0.484 g, 1.6 mmol), and
TiCl4 (0.312 g, 1.6 mmol) in CH2Cl2 (3 mL), 3r was isolated as a
colorless oil; yield: 0.224 g (44%).
IR (KBr): 2958 (s), 2870 (m), 1655 (s), 1616 (m), 1503 (m), 1468
(m), 1415 (m), 1399 (m), 1246 (s), 1233 (s), 1097 cm–1 (m).
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13C NMR (75 MHz, CDCl3): d = 21.4 (CH3), 52.4 (OCH3), 118.5 (q,
1JC,F = 320.4 Hz, CF3), 120.7 (CH), 124.0 (C), 128.1, 128.2, 128.5,
130.6 (CH), 139.0, 142.3, 143.1, 146.4 (C), 165.4 (CO2Me).
(q, 3J = 7.6 Hz, 2 H, CH2), 3.92 (s, 3 H, OCH3), 6.96 (br s, 1 H, CH),
7.10 (br s, 1 H, CH).
13C NMR (75 MHz, CDCl3): d = 14.9, 15.5 (CH3), 26.9, 28.6 (CH2),
1
52.5 (OCH3), 118.4, 128.5 (CH), 118.5 (q, JC,F = 320.0 Hz, CF3),
Methyl 2,4-Dimethyl-6-(trifluoromethylsulfonyloxy)benzoate
(4c)
Starting with 3c (0.773 g, 4.3 mmol), pyridine (0.70 mL,
8.6 mmol), and Tf2O (0.90 mL, 5.2 mmol) in CH2Cl2 (43 mL), 4c
was isolated as colorless oil; yield: 1.302 g (97%).
123.7, 145.6, 146.7, 148.7 (C), 165.6 (CO2Me).
MS (EI, 70 eV): m/z (%) = 340 (M+, 27), 309 (36), 207 (62), 176
(29), 175 (100).
Anal. Calcd for C13H15F3O5S (340.32): C, 45.88; H, 4.44. Found: C,
45.80; H, 4.49.
IR (KBr): 2959 (m), 1736 (s), 1624 (s), 1568 (m), 1425 (s), 1278 (s),
1212 (s), 1143 (s), 1089 (s), 1023 cm–1 (s).
1H NMR (250 MHz, CDCl3): d = 2.36 (s, 3 H, CH3), 2.40 (s, 3 H,
CH3), 3.92 (s, 3 H, OCH3), 6.94 (s, 1 H, CH), 7.06 (s, 1 H, CH).
13C NMR (63 MHz, CDCl3): d = 20.1, 21.2 (CH3), 52.4 (OCH3),
118.5 (q, 1JC,F = 320.4 Hz, CF3), 119.6 (CH), 123.7 (C), 131.3 (CH),
139.7, 142.4, 146.9 (C), 165.4 (CO2Me).
Methyl 3-Ethyl-4,5,6-trimethyl-2-(trifluoromethylsulfonyl-
oxy)benzoate (4g)
Starting with 3g (0.218 g, 1.0 mmol), pyridine (0.20 mL,
2.0 mmol), and Tf2O (0.20 mL, 1.2 mmol) in CH2Cl2 (10 mL), 4g
was isolated as yellow solid; yield: 0.326 g (94%); mp 67–68 °C;
Rf = 0.22 (n-heptane–EtOAc, 5:1).
3
MS (EI, 70 eV): m/z (%) = 312 (M+, 42), 281 (50), 179 (100), 147
(44), 119 (33), 91 (37).
1H NMR (250 MHz, CDCl3): d = 1.13 (t, J = 7.5 Hz, 3 H, CH3),
2.21 (s, 3 H, CH3), 2.25 (s, 3 H, CH3), 2.30 (s, 3 H, CH3), 2.77 (q,
3J = 7.5 Hz, 2 H, CH2), 3.90 (s, 3 H, OCH3).
Methyl 4-Methyl-2-(trifluoromethylsulfonyloxy)-5,6,7,8-tetra-
hydronaphthalene-1-carboxylate (4d)
Starting with 3d (0.269 g, 1.2 mmol), pyridine (0.20 mL,
2.4 mmol), and Tf2O (0.20 mL, 1.5 mmol) in CH2Cl2 (12 mL), 4d
was isolated as a colorless solid; yield: 0.416 g (97%).
13C NMR (75 MHz, CDCl3): d = 13.6, 16.5, 16.6, 17.8 (CH3), 20.8
(CH2), 52.5 (OCH3), 118.4 (q, 1JC,F = 320.0 Hz, CF3), 126.0, 133.5,
133.7, 137.0, 139.1, 141.0 (C), 166.7 (CO2Me).
MS (EI, 70 eV): m/z (%) = 354 (M+, 35), 323 (27), 221 (40), 190
(29), 189 (100).
HRMS (EI): m/z [M]+ calcd for C14H17F3O5S: 354.07433; found:
354.07433.
IR (KBr): 3443 (m), 2940 (m), 1735 (s), 1607 (m), 1423 (s), 1233
(s), 1214 (s), 1145 cm–1 (s).
1H NMR (300 MHz, CDCl3): d = 1.74–1.85 (m, 4 H, CH2), 2.26 (s,
3 H, CH3), 2.61 (t, J = 6.1 Hz, 2 H, CH2), 2.80 (t, J = 6.1 Hz, 2 H,
CH2), 3.92 (s, 3 H, OCH3), 6.94 (s, 1 H, CH).
13C NMR (75 MHz, CDCl3): d = 19.9 (CH3), 21.9, 22.2, 26.8, 27.8
[(CH2)4], 52.4 (OCH3), 116.3 (C), 119.6 (CH), 124.4, 136.7, 137.6,
140.9, 143.7 (C), 166.1 (CO2Me).
Methyl 3-Chloro-2,4-dimethyl-6-(trifluoromethylsulfonyl-
oxy)benzoate (4h)
Starting with 3h (0.279 g, 1.3 mmol), pyridine (0.20 mL,
2.6 mmol), and Tf2O (0.30 mL, 1.6 mmol) in CH2Cl2 (13 mL), 4h
was isolated as a colorless oil; yield: 0.440 g (98%).
MS (EI, 70 eV): m/z (%) = 352 (M+, 15), 219 (34), 187 (100).
IR (KBr): 2958 (w), 1740 (s), 1426 (s), 1272 (s), 1243 (s), 1214 (s),
1141 (s), 1023 cm–1 (m).
Methyl 3-Ethyl-2,4-dimethyl-6-(trifluoromethylsulfonyl-
oxy)benzoate (4e)
Starting with 3e (0.739 g, 3.6 mmol), pyridine (0.60 mL,
7.1 mmol), and Tf2O (0.70 mL, 4.3 mmol) in CH2Cl2 (36 mL), 4e
was isolated as colorless oil; yield: 1.070 g (89%).
1H NMR (300 MHz, CDCl3): d = 2.43 (s, 3 H, CH3), 2.44 (s, 3 H,
CH3), 3.95 (s, 3 H, OCH3), 7.08 (s, 1 H, CH).
13C NMR (75 MHz, CDCl3): d = 18.3, 21.3 (CH3), 52.8 (OCH3),
118.4 (q, JC,F = 318.2 Hz, CF3), 120.9 (CH), 126.3, 135.3, 137.0,
140.4, 143.9 (C), 164.9 (CO2Me).
GC-MS (EI, 70 eV): m/z (%) = 346 (M+, 35Cl, 20), 315 (27), 213
(100), 182 (44), 153 (51), 91 (57), 69 (64).
HRMS (EI): m/z [M]+ calcd for C11H10ClF3O5S: 345.9884; found:
345.9876.
IR (KBr): 2971 (s), 2884 (m), 1738 (s), 1607 (s), 1421 (s), 1278 (s),
1211 (s), 1147 (s), 1048 (s), 1012 cm–1 (s).
1H NMR (300 MHz, CDCl3): d = 1.11 (t, J = 7.1 Hz, 3 H, CH3),
2.34 (s, 3 H, CH3), 2.37 (s, 3 H, CH3), 2.66 (q, J = 6.9 Hz, 2 H,
CH2), 3.94 (s, 3 H, OCH3), 6.96 (s, 1 H, CH).
13C NMR (75 MHz, CDCl3): d = 13.2, 17.0, 20.5 (CH3), 22.6 (CH2),
52.6 (OCH3), 116.4 (C), 120.4 (CH), 120.8, 136.7, 140.4, 142.5,
144.2 (C), 166.3 (CO2Me).
MS (EI, 70 eV): m/z (%) = 340 (M+, 58), 309 (42), 207 (100), 176
(39), 175 (75), 146.5 (23), 119 (30).
Biaryls 6; General Procedure
A 1,4-dioxane soln of the arylboronic acid, K3PO4, Pd(PPh3)4, and
triflate 4 was stirred at 110 °C for 4–20 h. After cooling to r.t., sat.
aq NH4Cl soln was added, the organic and the aqueous layer were
separated, and the latter was extracted with Et2O. The combined or-
ganic layers were dried (Na2SO4), and filtered and the filtrate was
concentrated in vacuo. The residue was purified by chromatogra-
phy.
Anal. Calcd for C13H15F3O5S (340.32): C, 45.88; H, 4.44. Found: C,
46.11; H, 4.52.
Methyl 2,4-Diethyl-6-(trifluoromethylsulfonyloxy)benzoate (4f)
Starting with 3f (0.771 g, 3.7 mmol), pyridine (0.60 mL,
7.4 mmol), and Tf2O (0.70 mL, 4.4 mmol) in CH2Cl2 (37 mL), 4f
was isolated as colorless liquid; yield: 1.119 g (89%); Rf = 0.90
(CH2Cl2).
Methyl 4¢-Methoxy-3,4,5-trimethylbiphenyl-2-carboxylate (6a)
Starting with triflate 4a (0.228 g, 0.7 mmol), 4-methoxyphenyl-
boronic acid (0.138 g, 0.9 mmol), K3PO4 (0.238 g, 1.1 mmol),
Pd(PPh3)4 (0.024 g, 0.02 mmol, 3 mol%), and 1,4-dioxane
(1.8 mL), 6a was isolated as a colorless oil; yield: 0.158 g (79%).
IR (neat): 2973 (m), 2940 (m), 2880 (w), 1737 (s), 1621 (m), 1565
(m), 1424 (s), 1288 (m), 1220 (br, s), 1142 cm–1 (s).
IR (neat): 3031 (w), 2997 (m), 2948 (m), 2865 (w), 2837 (m), 1725
(br s), 1610 (s), 1578 (w), 1516 (s), 1462 (s), 1435 (s), 1394 (m),
1321 (w), 1290 (s), 1260 (s), 1248 (s), 1180 (s), 1164 (s), 1129 (s),
1080 (m), 1043 cm–1 (s).
3
1H NMR (250 MHz, CDCl3): d = 1.22 (t, J = 7.6 Hz, 3 H, CH3),
1.24 (t, 3J = 7.6 Hz, 3 H, CH3), 2.67 (q, 3J = 7.6 Hz, 2 H, CH2), 2.73
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Synthesis of Biaryls, Fluorenones, Cyclopenta[def]phenanthren-4-ones, and Benzophenones
453
1H NMR (500 MHz, CDCl3): d = 2.23 (s, 3 H, CH3), 2.28 (s, 3 H,
CH3), 2.33 (s, 3 H, CH3), 3.62 (s, 3 H, OCH3), 3.83 (s, 3 H, OCH3),
6.88–6.94 (m, 2 H, CH), 7.02 (s, 1 H, CH), 7.26–7.32 (m, 2 H, CH).
13C NMR (126 MHz, CDCl3): d = 15.4, 17.3, 20.7 (CH3), 51.7, 55.2
(OCH3), 113.6, 128.8, 129.3 (CH), 131.7, 133.1, 133.5, 134.2,
136.5, 137.7, 158.8 (C), 171.1 (CO2Me).
1H NMR (250 MHz, CDCl3): d = 2.43 (s, 3 H, CH3), 3.38 (s, 3 H,
OCH3), 3.83 (s, 3 H, OCH3), 6.89–6.95 (m, 2 H, CH), 7.16–7.17 (m,
2 H, CH), 7.29–7.31 (m, 1 H, CH), 7.32–7.35 (m, 2 H, CH), 7.36–
7.38 (m, 3 H, CH), 7.39–7.40 (m, 1 H, CH).
13C NMR (75 MHz, CDCl3): d = 21.3 (CH3), 51.7, 55.2 (OCH3),
113.7, 127.3, 128.2, 128.3, 129.2, 129.4, 129.6 (CH), 130.0, 133.0,
139.2, 139.9, 140.3, 140.7, 159.0 (C), 170.2 (CO2Me).
MS (EI, 70 eV): m/z (%) = 285 (18), 284 (M+, 100), 253 (69), 252
(26), 238 (27).
MS (EI, 70 eV): m/z (%) = 333 (20), 332 (M+, 85), 302 (22), 301
(100), 258 (14), 215 (25).
HRMS (EI): m/z [M]+ calcd for C22H20O3: 332.14070; found:
HRMS (EI): m/z [M]+ calcd for C18H20O3: 284.14070; found:
284.13999.
332.14079.
Methyl 3,4,5-Trimethylbiphenyl-2-carboxylate (6b)
Starting with triflate 4a (0.228 g, 0.7 mmol), phenylboronic acid
(0.111 g, 0.9 mmol), K3PO4 (0.238 g, 1.1 mmol), Pd(PPh3)4
(0.024 g, 0.02 mmol, 3 mol%), and 1,4-dioxane (1.8 mL), 6b was
isolated as a colorless solid; yield: 0.154 g (87%); mp 63–64 °C.
Methyl 5¢-Methyl-1,1¢;3¢,1¢¢-terphenyl-2¢-carboxylate (6e)
Starting with triflate 4b (0.097 g, 0.26 mmol), phenylboronic acid
(0.041 g, 0.3 mmol), K3PO4 (0.089 g, 0.4 mmol), Pd(PPh3)4
(0.009 g, 0.01 mmol, 3 mol%), and 1,4-dioxane (0.7 mL), 6e was
isolated as a colorless solid; yield: 0.062 g (79%); mp 120–122 °C.
IR (KBr): 3452 (br m), 3411 (m), 3065 (w), 3036 (w), 2995 (w),
2946 (m), 2925 (w), 1714 (s), 1598 (w), 1558 (w), 1502 (w), 1458
(m), 1433 (s), 1395 (w), 1382 (w), 1319 (w), 1272 (s), 1262 (s),
1188 (s), 1166 (s), 1134 (m), 1078 (w), 1047 (s), 1009 cm–1 (w).
IR (KBr): 3437 (m), 3064 (w), 3028 (w), 2946 (w), 2918 (w), 1731
(s), 1600 (m), 1497 (w), 1450 (w), 1436 (w), 1259 (s), 1189 (m),
1104 (s), 1055 cm–1 (m).
1H NMR (250 MHz, CDCl3): d = 2.23 (s, 3 H, CH3), 2.29 (s, 3 H,
CH3), 2.34 (s, 3 H, CH3), 3.56 (s, 3 H, OCH3), 7.04 (s, 1 H, CH),
7.26–7.40 (m, 5 H, CH).
13C NMR (75 MHz, CDCl3): d = 15.4, 17.3, 20.8 (CH3), 51.8
(OCH3), 127.0, 128.1, 128.2, 128.8 (CH), 131.6, 133.2, 134.7,
136.9, 137.8, 141.0 (C), 171.0 (CO2Me).
1H NMR (250 MHz, CDCl3): d = 2.44 (s, 3 H, CH3), 3.36 (s, 3 H,
OCH3), 7.19 (m, 2 H, CH), 7.30–7.40 (m, 10 H, CH).
13C NMR (75 MHz, CDCl3): d = 21.3 (CH3), 51.6 (OCH3), 127.4,
128.2, 128.3, 129.5, 130.1 (CH), 139.3, 140.4, 140.6 (C), 170.0
(CO2Me).
MS (EI, 70 eV): m/z (%) = 302 (M+, 53), 272 (20), 271 (100), 228
(20), 165 (12).
MS (EI, 70 eV): m/z (%) = 255 (41), 254 (M+, 100), 223 (100), 222
(83), 180 (77), 179 (76), 165 (82).
HRMS (EI): m/z [M]+ calcd for C17H18O2: 254.1301; found:
HRMS (EI): m/z [M]+ calcd for C21H18O2: 302.13013; found:
302.13015.
254.1295.
Methyl 4,5¢-Dimethyl-1,1¢;3¢,1¢¢-terphenyl-2¢-carboxylate (6f)
Starting with triflate 4b (0.101 g, 0.27 mol), 4-methylphenylboron-
ic acid (0.048 g, 0.4 mmol), K3PO4 (0.091 g, 0.4 mmol), Pd(PPh3)4
(0.009 g, 0.01 mmol, 3 mol%), and 1,4-dioxane (0.7 mL), 6f was
isolated as a colorless oil; yield: 0.064 g (75%).
Methyl 3,4,4¢,5-Tetramethylbiphenyl-2-carboxylate (6c)
Starting with triflate 4a (0.300 g, 0.9 mmol), 4-methylphenylboron-
ic acid (0.163 g, 1.2 mmol), K3PO4 (0.312 g, 1.5 mmol), Pd(PPh3)4
(0.032 g, 0.03 mmol, 3 mol%), and 1,4-dioxane (2.3 mL), 6c was
isolated as a colorless solid; yield: 0.215 g (87%); mp 67–68 °C.
IR (neat): 3027 (m), 2947 (m), 2921 (m), 2865 (w), 1729 (br s),
1600 (s), 1574 (m), 1515 (s), 1441 (s), 1427 (s), 1262 (br s), 1190
(s), 1100 (s), 1052 cm–1 (s).
1H NMR (250 MHz, CDCl3): d = 2.40 (s, 3 H, CH3), 2.45 (s, 3 H,
CH3), 3.39 (s, 3 H, OCH3), 7.19 (m, 2 H, CH), 7.22 (s, 1 H, CH),
7.29 (s, 1 H, CH), 7.32 (s, 1 H, CH), 7.34–7.43 (m, 6 H, CH).
13C NMR (75 MHz, CDCl3): d = 21.2, 21.3 (CH3), 51.7 (OCH3),
127.4, 128.1, 128.2, 128.2, 128.3, 128.5, 129.0, 129.4, 129.6, 130.0
(CH), 137.1, 137.7, 139.0, 139.3, 140.4, 140.7, 142.3 (C), 170.2
(CO2Me).
MS (EI, 70 eV): m/z (%) = 316 (M+, 46), 286 (23), 285 (100), 242
(22), 241 (23), 239 (20).
HRMS (EI): m/z [M]+ calcd for C22H20O2: 316.14578; found:
316.14543.
IR (KBr): 3438 (w), 3026 (w), 2953 (m), 2922 (w), 2862 (w), 1734
(s), 1515 (w), 1460 (w), 1425 (m), 1383 (w), 1274 (s), 1260 (s),
1213 (w), 1184 (m), 1162 (m), 1126 (m), 1081 (w), 1043 (m), 1019
cm–1 (w).
1H NMR (250 MHz, CDCl3): d = 2.29 (s, 3 H, CH3), 2.36 (s, 3 H,
CH3), 2.40 (s, 3 H, CH3), 2.44 (s, 3 H, CH3), 3.68 (s, 3 H, OCH3),
7.12 (s, 1 H, CH), 7.23 (s, 1 H, CH), 7.32 (s, 1 H, CH), 7.36–7.43
(s, 2 H, CH).
13C NMR (75 MHz, CDCl3,): d = 15.2, 17.2, 20.6, 20.9 (CH3), 51.6
(OCH3), 127.9, 128.7, 128.8 (CH), 131.5, 133.0 134.3, 136.5,
136.7, 137.6, 138.0 (C), 171.0 (CO2Me).
MS (EI, 70 eV): m/z (%) = 268 (M+, 96), 237 (100), 236 (29), 221
(29), 194 (31), 179 (39).
HRMS (EI): m/z [M]+ calcd for C18H20O2: 268.1458; found:
268.1457.
Methyl 4¢-Methoxy-3,5-dimethylbiphenyl-2-carboxylate (6g)
Starting with triflate 4c (0.219 g, 0.7 mmol), 4-methoxyphenyl-
boronic acid (0.138 g, 0.9 mmol), K3PO4 (0.238 g, 1.1 mmol),
Pd(PPh3)4 (0.024 g, 0.02 mmol, 3 mol%), and 1,4-dioxane
(1.8 mL), 6g was isolated as a colorless oil; yield: 0.180 g (95%).
Methyl 4-Methoxy-5¢-methyl-1,1¢;3¢,1¢¢-terphenyl-2¢-carboxy-
late (6d)
Starting with triflate 4b (0.101 g, 0.27 mmol), 4-methoxyphenyl-
boronic acid (0.053 g, 0.4 mmol), K3PO4 (0.091 g, 0.4 mmol),
Pd(PPh3)4 (0.009 g, 0.01 mmol, 3 mol%), and 1,4-dioxane
(0.7 mL), 6d was isolated as a colorless solid; yield: 0.075 g (84%);
mp 82–83 °C.
IR (neat): 3033 (w), 2997 (w), 2950 (s), 2925 (s), 2854 (m), 1727
(br s), 1609 (s), 1576 (w), 1514 (s), 1457 (m), 1442 (m), 1379 (w),
1263 (s), 1250 (s), 1180 (s), 1128 (m), 1082 (s), 1035 cm–1 (s).
1H NMR (250 MHz, CDCl3): d = 2.34 (s, 6 H, CH3), 3.59 (s, 3 H,
OCH3), 3.83 (s, 3 H, OCH3), 6.87–6.89 (m, 1 H, CH), 6.91–6.93 (m,
1 H, CH), 6.99–7.00 (m, 2 H, CH), 7.24–7.26 (m, 1 H, CH), 7.28–
7.30 (m, 1 H, CH).
IR (KBr): 3437 (br m), 3034 (w), 3002 (w), 2953 (w), 2837 (w),
1729 (s), 1611 (m), 1599 (w), 1514 (s), 1457 (w), 1441 (w), 1271
(s), 1247 (s), 1177 (m), 1103 (m), 1053 (m), 1030 cm–1 (m).
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13C NMR (75 MHz, CDCl3): d = 19.6, 21.2 (CH3), 51.8, 55.2
(OCH3), 113.7, 127.9, 129.2, 129.5 (CH), 130.3, 133.5, 135.4,
139.3, 139.8, 158.9 (C), 170.7 (CO2Me).
HRMS (EI): m/z [M]+ calcd for C20H22O3: 310.15635; found:
310.15590.
Methyl 4-Methyl-2-phenyl-5,6,7,8-tetrahydronaphthalene-1-
carboxylate (6k)
Starting with triflate 4d (0.201 g, 0.6 mmol), phenylboronic acid
(0.090 g, 0.7 mmol), K3PO4 (0.193 g, 0.9 mmol), Pd(PPh3)4
(0.020 g, 0.02 mmol, 3 mol%), and 1,4-dioxane (1.4 mL), 6k was
isolated as a colorless solid; yield: 0.142 g (89%); mp 151 °C; Rf =
0.23 (n-heptane–EtOAc, 10:1).
MS (EI, 70 eV): m/z (%) = 270 (M+, 100), 239 (97), 238 (45), 223
(12), 196 (17).
HRMS (EI): m/z [M]+ calcd for C17H18O3: 270.12505; found:
270.12425.
Methyl 3,5-Dimethylbiphenyl-2-carboxylate (6h)
Starting with triflate 4c (0.153 g, 0.5 mmol), phenylboronic acid
(0.078 g, 0.6 mmol), K3PO4 (0.166 g, 0.8 mmol), Pd(PPh3)4
(0.017 g, 0.02 mmol, 3 mol%), and 1,4-dioxane (1.2 mL), 6h was
isolated as a colorless oil; yield: 0.107 g (91%).
IR (KBr): 2924 (m), 2863 (m), 1715 (s), 1635 (br, w), 1600 (w),
1557 (w), 1451 (m), 1432 (m), 1396 (w), 1252 cm–1 (s).
1H NMR (250 MHz, CDCl3): d = 1.71–1.92 (m, 4 H, CH2), 2.26 (s,
3 H, CH3), 2.67 (t, 3J = 6.1 Hz, 2 H, CH2), 2.78 (t, 3J = 6.0 Hz, 2 H,
CH2), 3.55 (s, 3 H, OCH3), 7.03 (br s, 1 H, CH), 7.26–7.41 (m, 5 H,
CH).
13C NMR (75 MHz, CDCl3): d = 19.7 (CH3), 22.5, 22.8, 26.9, 27.5
[(CH2)4], 51.7 (OCH3), 127.1, 128.2, 128.2, 128.4 (CH), 131.0,
134.0, 135.1, 136.8, 138.2, 141.0 (C), 170.7 (CO2Me).
MS (EI, 70 eV): m/z (%) = 280 (M+, 73), 248 (100), 249 (42), 233
(23), 205 (21).
HRMS (EI): m/z [M]+ calcd for C19H20O2: 280.14578; found:
280.14552.
IR (neat): 3058 (w), 3030 (w), 2949 (m), 2924 (m), 2857 (w), 1727
(br s), 1606 (m), 1577 (w), 1497 (w), 1436 (m), 1380 (w), 1269 (s),
1189 (m), 1128 (m), 1084 (s), 1032 cm–1 (w).
1H NMR (250 MHz, CDCl3): d = 2.36 (s, 6 H, CH3), 3.55 (s, 3 H,
OCH3), 7.03 (br s, 2 H, CH), 7.27–7.41 (m, 5 H, CH).
13C NMR (75 MHz, CDCl3): d = 19.6, 21.2 (CH3), 51.7 (OCH3),
127.2, 127.9, 128.1, 128.2, 129.9 (CH), 130.3, 135.5, 139.4, 140.3,
141.1 (C), 170.4 (CO2Me).
MS (EI, 70 eV): m/z (%) = 240 (M+, 60), 210 (16), 209 (100), 208
(26), 166 (24), 165 (42).
HRMS (EI): m/z [M]+ calcd for C16H16O2: 240.11448; found:
240.11519.
Methyl 4-Methyl-2-(4-tolyl)-5,6,7,8-tetrahydronaphthalene-1-
carboxylate (6l)
Starting with triflate 4d (0.201 g, 0.57 mmol), 4-methylphenylbo-
ronic acid (0.101 g, 0.7 mmol), K3PO4 (0.193 g, 0.9 mmol),
Pd(PPh3)4 (0.034 g, 0.03 mmol, 5 mol%), and 1,4-dioxane
(1.4 mL), 6l was isolated as a colorless solid; yield: 0.139 g (83%);
mp 82 °C; Rf = 0.22 (n-heptane–EtOAc, 15:1).
Methyl 3,4¢,5-Trimethylbiphenyl-2-carboxylate (6i)
Starting with triflate 4c (0.500 g, 1.6 mmol), 4-methylphenylboron-
ic acid (0.283 g, 2.1 mmol), K3PO4 (0.543 g, 2.6 mmol), Pd(PPh3)4
(0.055 g, 0.05 mmol, 3 mol%), and 1,4-dioxane (4.0 mL), 6i was
isolated as a colorless oil; yield: 0.181 g (44%).
IR (KBr): 2928 (m), 2860 (m), 1724 (s), 1596 (w), 1558 (w), 1518
(m), 1458 (m), 1434 (m), 1392 (w), 1252 cm–1 (s).
1H NMR (250 MHz, CDCl3): d = 1.70–1.91 (m, 4 H, CH2), 2.25 (s,
3 H, CH3), 2.36 (s, 3 H, CH3), 2.66 (t, 3J = 6.1 Hz, 2 H, CH2), 2.77
(t, 3J = 5.8 Hz, 2 H, CH2), 3.58 (s, 3 H, OCH3), 7.01 (s, 1 H, CH),
7.12–7.28 (m, 4 H, CH).
13C NMR (75 MHz, CDCl3): d = 19.7, 21.1 (CH3), 22.5, 22.8, 26.9,
27.5 [(CH2)4], 51.7 (OCH3), 126.8, 128.1, 128.4, 129.0, 129.4 (CH),
131.0, 133.9, 134.8, 136.7, 138.0, 138.2, 170.8 (C), 181.3 (CO2Me).
IR (neat): 3024 (m), 2993 (m), 2948 (m), 2923 (m), 2865 (m), 1726
(br s), 1605 (m), 1576 (w), 1515 (m), 1437 (m), 1269 (s), 1188 (m),
1181 (m), 1127 (m), 1082 cm–1 (s).
1H NMR (250 MHz, CDCl3): d = 2.36 (s, 6 H, CH3), 2.37 (s, 3 H,
CH3), 3.59 (s, 3 H, OCH3), 7.01 (m, 2 H, CH), 7.16–7.19 (m, 2 H,
CH), 7.22–7.27 (m, 2 H, CH).
13C NMR (75 MHz, CDCl3): d = 19.6, 21.1, 21.2 (CH3), 51.7
(OCH3), 128.0, 129.0, 129.7, (CH), 130.3, 135.4, 136.9, 138.1,
139.3, 140.2 (C), 170.6 (CO2Me).
MS (EI, 70 eV): m/z (%) = 254 (M+, 68), 223 (100), 222 (36), 179
(27), 165 (42).
HRMS (EI): m/z [M]+ calcd for C17H18O2: 254.13013; found:
254.12981.
MS (EI, 70 eV): m/z (%) = 294 (M+, 77), 263 (41), 262 (100), 247
(55), 219 (23).
Anal. Calcd for C20H22O2 (294.39): C, 81.60; H, 7.53. Found: C,
81.22; H, 7.65.
Methyl 4-Ethyl-4¢-methoxy-3,5-dimethylbiphenyl-2-carboxy-
late (6m)
Starting with triflate 4e (0.201 g, 0.6 mmol), 4-methoxyphenylbo-
ronic acid (0.117 g, 0.8 mmol), K3PO4 (0.200 g, 0.9 mmol),
Pd(PPh3)4 (0.021 g, 0.02 mmol, 3 mol%), and 1,4-dioxane
(1.5 mL), 6m was isolated as a colorless solid; yield: 0.125 g (71%);
mp 61 °C; Rf = 0.14 (n-heptane–EtOAc, 10:1).
Methyl 2-(4-Methoxyphenyl)-4-methyl-5,6,7,8-tetrahydro-
naphthalene-1-carboxylate (6j)
Starting with triflate 4d (0.250 g, 0.7 mmol), 4-methoxyphenyl-
boronic acid (0.140 g, 0.9 mmol), K3PO4 (0.242 g, 1.1 mmol),
Pd(PPh3)4 (0.024 g, 0.02 mmol, 3 mol%), and 1,4-dioxane
(1.8 mL), 6j was isolated as a colorless oil; yield: 0.128 g (58%);
Rf = 0.53 (n-heptane–EtOAc, 15:1).
1H NMR (500 MHz, CDCl3): d = 1.72–1.90 (m, 4 H, CH2), 2.25 (s,
3 H, CH3), 2.66 (t, 3J = 6.1 Hz, 2 H, CH2), 2.77 (t, 3J = 6.1 Hz, 2 H,
CH2), 3.59 (s, 3 H, OCH3), 3.82 (s, 3 H, OCH3), 6.86–6.95 (m, 2 H,
CH), 7.01 (s, 1 H, CH), 7.24–7.32 (m, 2 H, CH).
13C NMR (126 MHz, CDCl3): d = 19.7 (CH3), 22.5, 22.8, 26.9, 27.5
[(CH2)4], 51.8, 55.2 (OCH3), 113.7, 128.4, 129.3 (CH), 131.0,
133.4, 133.9, 134.7, 136.3, 138.1, 158.8 (C), 170.9 (CO2Me).
IR (KBr): 2996 (m), 2964 (m), 2952 (m), 2935 (m), 1725 (s), 1610
(m), 1595 (m), 1517 (s), 1465 (m), 1447 cm–1 (m).
3
1H NMR (250 MHz, CDCl3): d = 1.13 (t, J = 7.6 Hz, 3 H, CH3),
3
2.30 (s, 3 H, CH3), 2.35 (s, 3 H, CH3), 2.69 (q, J = 7.6 Hz, 2 H,
CH2), 3.60 (s, 3 H, OCH3), 3.82 (s, 3 H, OCH3), 6.85–6.94 (m, 2 H,
CH), 7.00 (s, 1 H, CH), 7.21–7.32 (m, 2 H, CH).
13C NMR (75 MHz, CDCl3): d = 13.2, 16.3, 19.9 (CH3), 22.6 (CH2),
51.8, 55.2 (OCH3), 113.6, 129.3 (CH), 132.0, 132.5, 133.4, 136.5,
137.2, 140.0, 158.8 (C), 171.3 (CO2Me).
MS (EI, 70 eV): m/z (%) = 310 (M+, 100), 279 (33), 278 (84), 263
(40), 247 (24).
Synthesis 2009, No. 3, 445–463 © Thieme Stuttgart · New York

PAPER
Synthesis of Biaryls, Fluorenones, Cyclopenta[def]phenanthren-4-ones, and Benzophenones
455
MS (EI, 70 eV): m/z (%) = 298 (M+, 100), 283 (33), 267 (31), 251
(32), 239 (12).
HRMS (EI): m/z [M]+ calcd for C19H22O3: 298.15635; found:
298.15567.
Methyl 3,5-Diethyl-4¢-methylbiphenyl-2-carboxylate (6q)
Starting with triflate 4f (0.245 g, 0.7 mmol), 4-methylphenylboron-
ic acid (0.128 g, 0.9 mmol), K3PO4 (0.244 g, 1.2 mmol), Pd(PPh3)4
(0.034 g, 0.03 mmol, 4 mol%), and 1,4-dioxane (1.8 mL), 6q was
isolated as a colorless oil; yield: 0.154 g (76%); Rf = 0.39 (n-hep-
tane–EtOAc, 10:1).
Methyl 4-Ethyl-3,5-dimethylbiphenyl-2-carboxylate (6n)
Starting with triflate 4e (0.231 g, 0.7 mmol), phenylboronic acid
(0.107 g, 0.9 mmol), K3PO4 (0.231 g, 1.1 mmol), Pd(PPh3)4
(0.031 g, 0.03 mmol, 4 mol%), and 1,4-dioxane (1.7 mL), 6n was
isolated as a colorless solid; yield: 0.084 g (46%); mp 60 °C; Rf =
0.14 (n-heptane–EtOAc, 20:1).
IR (neat): 3024 (m), 2966 (s), 2874 (m), 1727 (s), 1603 (m), 1573
(m), 1516 (m), 1458 (m), 1430 (m), 1278 cm–1 (s).
3
1H NMR (250 MHz, CDCl3): d = 1.24 (t, J = 7.6 Hz, 3 H, CH3),
1.25 (t, 3J = 7.6 Hz, 3 H, CH3), 2.37 (s, 3 H, CH3), 2.66 (q,
3J = 7.6 Hz, 2 H, CH2), 2.68 (q, 3J = 7.6 Hz, 2 H, CH2), 3.57 (s, 3 H,
OCH3), 7.01–7.08 (m, 2 H, CH), 7.14–7.29 (m, 4 H, CH).
3
1H NMR (250 MHz, CDCl3): d = 1.14 (t, J = 7.6 Hz, 3 H, CH3),
2.32 (s, 3 H, CH3), 2.36 (br s, 3 H, CH3), 2.71 (q, 3J = 7.6 Hz, 2 H,
CH2), 3.56 (s, 3 H, OCH3), 7.03 (s, 1 H, CH), 7.22–7.41 (m, 5 H,
CH).
13C NMR (75 MHz, CDCl3): d = 15.4, 15.8, 21.1 (CH3), 26.8, 28.7
(CH2), 51.7 (OCH3), 126.9, 127.0, 128.1, 129.0 (CH), 130.1, 136.9,
138.3, 140.2, 141.7, 145.8 (C), 170.7 (CO2Me).
MS (EI, 70 eV): m/z (%) = 282 (M+, 100), 251 (87), 250 (31), 235
(19), 2221 (89).
13C NMR (75 MHz, CDCl3): d = 13.2, 16.3, 19.9 (CH3), 22.6 (CH2),
51.8 (OCH3), 127.1, 128.2, 128.2, 129.3 (CH), 132.0, 132.7, 137.0,
137.3, 140.4, 141.0 (C), 171.1 (CO2Me).
MS (EI, 70 eV): m/z (%) = 268 (M+, 100), 253 (40), 237 (71), 221
(31), 178 (20).
Anal. Calcd for C19H22O2 (282.38): C, 80.82; H, 7.85. Found: C,
80.57; H, 7.99.
HRMS (EI): m/z [M]+ calcd for C18H20O2: 268.14578; found:
268.14558.
Methyl 3,5-Diethyl-4¢-methoxybiphenyl-2-carboxylate (6r)
Starting with triflate 4f (0.221 g, 0.65 mmol), 4-methoxyphenyl-
boronic acid (0.129 g, 0.9 mmol), K3PO4 (0.221 g, 1.0 mmol),
Pd(PPh3)4 (0.030 g, 0.03 mmol, 4 mol%), and 1,4-dioxane
(1.6 mL), 6r was isolated as a yellow oil; yield: 0.167 g (86%); Rf =
0.52 (toluene–EtOAc, 30:1).
Methyl 4-Ethyl-3,4¢,5-trimethylbiphenyl-2-carboxylate (6o)
Starting with triflate 4e (0.201 g, 0.6 mmol), 4-methylphenylboron-
ic acid (0.105 g, 0.8 mmol), K3PO4 (0.200 g, 0.9 mmol), Pd(PPh3)4
(0.035 g, 0.03 mmol, 5 mol%), and 1,4-dioxane (1.5 mL), 6o was
isolated as a colorless oil; yield: 0.125 g (75%); Rf = 0.21 (n-hep-
tane–EtOAc, 10:1).
IR (neat): 2966 (s), 2936 (m), 2875 (m), 2836 (m), 1725 (s), 1609
(s), 1577 (m), 1515 (s), 1461 (s), 1430 cm–1 (s).
3
1H NMR (250 MHz, CDCl3): d = 1.24 (t, J = 7.6 Hz, 3 H, CH3),
IR (neat): 3023 (m), 2968 (s), 2948 (m), 2924 (m), 2872 (m), 1727
(s), 1596 (m), 1557 (w), 1517 (m), 1454 cm–1 (m).
1.25 (t, 3J = 7.6 Hz, 3 H, CH3), 2.67 (q, 3J = 7.6 Hz, 2 H, CH2), 2.68
(q, 3J = 7.6 Hz, 2 H, CH2), 3.58 (s, 3 H, OCH3), 3.83 (s, 3 H, OCH3),
6.86–8.96 (m, 2 H, CH), 6.99–7.08 (m, 2 H, CH), 7.23–7.34 (m, 2
H, CH).
3
1H NMR (250 MHz, CDCl3): d = 1.14 (t, J = 7.6 Hz, 3 H, CH3),
2.32 (s, 3 H, CH3), 2.36 (br s, 6 H, CH3), 2.71 (q, 3J = 7.6 Hz, 2 H,
CH2), 3.60 (s, 3 H, OCH3), 7.02 (s, 1 H, CH), 7.12–7.28 (m, 4 H,
CH).
13C NMR (63 MHz, CDCl3): d = 15.4, 15.8 (CH3), 26.8, 28.7 (CH2),
51.7, 55.2 (OCH3), 113.7, 126.9, 129.3 (CH), 130.1, 133.7, 139.8,
141.6, 145.7, 158.9 (C), 170.7 (CO2Me).
MS (EI, 70 eV): m/z (%) = 298 (M+, 100), 267 (45), 266 (32), 237
(70), 235 (18).
13C NMR (63 MHz, CDCl3): d = 13.2, 16.3, 19.9, 21.1 (CH3), 22.6
(CH2), 51.8 (OCH3), 128.0, 128.9, 129.3 (CH), 131.9, 132.5, 136.7,
136.9, 137.2, 138.0, 140.2 (C), 171.2 (CO2Me).
MS (EI, 70 eV): m/z (%) = 282 (M+, 100), 267 (34), 251 (48), 235
(37), 182 (54).
Anal. Calcd for C19H22O3 (298.38): C, 76.48; H, 7.43. Found: C,
76.47; H, 7.58.
HRMS (EI): m/z [M]+ calcd for C19H22O2: 282.16143; found:
282.16140.
Methyl 3,5-Diethyl-3¢,4¢,5¢-trimethoxybiphenyl-2-carboxylate
(6s)
Methyl 3,5-Diethylbiphenyl-2-carboxylate (6p)
Starting with triflate 4f (0.180 g, 0.53 mmol), 3,4,5-trimethoxyphe-
nylboronic acid (0.146 g, 0.7 mmol), K3PO4 (0.180 g, 0.9 mmol),
Pd(PPh3)4 (0.018 g, 0.02 mmol, 3 mol%), and 1,4-dioxane
(1.3 mL), 6s was isolated as a yellow solid; yield: 0.113 g (59%);
mp 84–87 °C; Rf = 0.32 (toluene–EtOAc, 10:1).
Starting with triflate 4f (0.214 g, 0.63 mmol), phenylboronic acid
(0.100 g, 0.8 mmol), K3PO4 (0.214 g, 1.0 mmol), Pd(PPh3)4
(0.022 g, 0.02 mmol, 3 mol%), and 1,4-dioxane (1.6 mL), 6p was
isolated as a colorless oil; yield: 0.149 g (88%); Rf = 0.17 (n-hep-
tane–EtOAc, 20:1).
3
1H NMR (250 MHz, CDCl3): d = 1.24 (t, J = 7.6 Hz, 3 H, CH3),
IR (neat): 3057 (m), 3028 (m), 2966 (s), 2874 (m), 1727 (s), 1603
(m), 1577 (m), 1459 (m), 1430 (m), 1279 cm–1 (s).
1.26 (t, 3J = 7.6 Hz, 3 H, CH3), 2.67 (q, 3J = 7.6 Hz, 4 H, CH2), 3.60
(s, 3 H, OCH3), 3.86 (br s, 6 H, OCH3), 3.87 (s, 3 H, OCH3), 6.59
(s, 2 H, CH), 7.06 (d, 4J = 1.7 Hz, 1 H, CH), 7.08 (d, 4J = 1.7 Hz, 1
H, CH).
3
1H NMR (250 MHz, CDCl3): d = 1.25 (t, J = 7.6 Hz, 3 H, CH3),
1.26 (t, 3J = 7.6 Hz, 3 H, CH3), 2.68 (q, 3J = 7.6 Hz, 2 H, CH2), 2.70
(q, 3J = 7.6 Hz, 2 H, CH2), 3.54 (s, 3 H, OCH3), 7.06 (d, 4J = 1.7 Hz,
1 H, CH), 7.08 (d, 4J = 1.7 Hz, 1 H, CH), 7.27–7.48 (m, 5 H, CH).
13C NMR (75 MHz, CDCl3): d = 15.4, 15.7 (CH3), 26.8, 28.7 (CH2),
51.9, 56.1, 60.9 (OCH3), 105.4, 126.6, 127.3 (CH), 130.2, 136.8,
137.2, 140.0, 141.7, 145.8, 153.0 (C), 170.6 (CO2Me).
MS (EI, 70 eV): m/z (%) = 358 (M+, 100), 343 (53), 297 (14), 295
(31).
13C NMR (75 MHz, CDCl3): d = 15.4, 15.8 (CH3), 26.8, 28.7 (CH2),
51.7 (OCH3), 126.9, 127.2, 127.3, 128.2, 128.7 (CH), 130.1, 140.3,
141.3, 141.8, 145.8 (C), 170.5 (CO2Me).
MS (EI, 70 eV): m/z (%) = 268 (M+, 96), 237 (100), 236 (69), 207
HRMS (EI): m/z [M]+ calcd for C21H26O5: 358.17748; found:
(95), 165 (12).
358.17676.
Anal. Calcd for C18H20O2 (268.35): C, 80.56; H, 7.51. Found: C,
80.56; H, 7.72.
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S. Reim et al.
PAPER
Methyl 6-Ethyl-4¢-methoxy-3,4,5-trimethylbiphenyl-2-carboxy-
late (6t)
ane (1.7 mL), 6w was isolated as a colorless solid; yield: 0.204 g
(88%); mp 84–85 °C; Rf = 0.41 (n-heptane–EtOAc, 10:1).
Starting with triflate 4g (0.244 g, 0.7 mmol), 4-methoxyphenyl-
boronic acid (0.137 g, 0.9 mmol), K3PO4 (0.233 g, 1.1 mmol),
Pd(PPh3)4 (0.032 g, 0.03 mmol, 4 mol%), and 1,4-dioxane
(1.7 mL), 6t was isolated as a yellow solid; yield: 0.096 g (44%);
mp 89 °C; Rf = 0.37 (toluene–EtOAc, 50:1).
IR (KBr): 2954 (m), 2928 (m), 1727 (s), 1617 (m), 1570 (m), 1438
(m), 1387 (m), 1326 (s), 1262 (s), 1232 cm–1 (m).
1H NMR (250 MHz, CDCl3): d = 2.41 (s, 3 H, CH3), 2.44 (s, 3 H,
CH3), 3.59 (s, 3 H, OCH3), 7.09 (s, 1 H, CH), 7.44 (d, 3J = 8.1 Hz,
2 H, CH), 7.64 (d, 3J = 8.1 Hz, 2 H, CH).
3
1H NMR (250 MHz, CDCl3): d = 0.92 (t, J = 7.5 Hz, 3 H, CH3),
13C NMR (75 MHz, CDCl3): d = 18.0, 21.0 (CH3), 52.2 (OCH3),
2.22 (s, 3 H, CH3), 2.24 (s, 3 H, CH3), 2.30 (s, 3 H, CH3), 2.44 (q,
3J = 7.5 Hz, 2 H, CH2), 3.41 (s, 3 H, OCH3), 3.83 (s, 3 H, OCH3),
6.83–6.93 (m, 2 H, CH), 7.07–7.17 (m, 2 H, CH).
124.1 (q, 1J = 272.0 Hz, CF3), 125.3 (q, 3J = 3.8 Hz, CF3CCH),
2
128.6, 129.4 (CH), 129.7 (q, J = 32.5 Hz, CF3C), 132.5, 133.8,
135.2, 136.4, 138.0, 143.7 (C), 169.3 (CO2Me).
MS (EI, 70 eV): m/z (%) = 342 (M+, 35Cl, 64), 311 (100), 248 (21).
HRMS (EI): m/z (M+, 35Cl) calcd for C17H14ClF3O2: 342.06289;
found: 342.06222.
13C NMR (75 MHz, CDCl3): d = 14.7, 16.2, 16.3, 17.6 (CH3), 23.7
(CH2), 51.5, 55.1 (OCH3), 113.0, 130.8 (CH), 129.1, 132.1, 133.5,
135.2, 135.8, 135.9, 138.7, 158.4 (C), 171.0 (CO2Me).
MS (EI, 70 eV): m/z (%) = 312 (M+, 100), 281 (21), 265 (36), 238
(17), 237 (16).
Methyl 4-Chloro-3,5-dimethylbiphenyl-2-carboxylate (6x)
Starting with triflate 4h (0.208 g, 0.6 mmol), phenylboronic acid
(0.095 g, 0.8 mmol), K3PO4 (0.204 g, 1.0 mmol), Pd(PPh3)4
(0.021 g, 0.02 mmol, 3 mol%), and 1,4-dioxane (1.5 mL), 6x was
isolated as a colorless solid; yield: 0.097 g (59%); mp 55 °C.
HRMS (EI): m/z [M]+ calcd for C20H24O3: 312.17200; found:
312.17130.
Methyl 4-Chloro-4¢-methoxy-3,5-dimethylbiphenyl-2-carboxy-
late (6u)
Starting with triflate 4h (0.257 g, 0.74 mmol), 4-methoxyphenyl-
boronic acid (0.146 g, 1.0 mmol), K3PO4 (0.250 g, 1.2 mmol), Pd
catalyst (0.025 g, 0.02 mmol, 3 mol%), and 1,4-dioxane (1.9 mL),
6u was isolated as a colorless oil; yield: 0.186 g (82%); Rf =
0.39 (toluene).
IR (KBr): 3428 (m), 2994 (w), 2946 (w), 1722 (s), 1466 (m), 1447
(m), 1433 (m), 1438 (m), 1252 (s), 1226 (m), 1094 (m), 1012 cm–1
(m).
1H NMR (300 MHz, CDCl3): d = 2.41 (s, 3 H, CH3), 2.43 (s, 3 H,
CH3), 3.57 (s, 3 H, OCH3), 7.12 (s, 1 H, CH), 7.25–7.38 (m, 5 H,
CH).
13C NMR (75 MHz, CDCl3): d = 17.9, 21.0 (CH3), 52.0 (OCH3),
127.5, 128.1, 128.3, 129.5 (CH), 132.5, 133.3, 134.3, 137.6, 137.8,
140.0 (C), 169.7 (CO2Me).
IR (neat): 3035 (m), 2998 (m), 2950 (m), 2837 (m), 1728 (s), 1610
(s), 1514 (s), 1456 (s), 1439 (s), 1383 cm–1 (m).
1H NMR (250 MHz, CDCl3): d = 2.34 (br s, 3 H, CH3), 2.41 (br s, 3
H, CH3), 3.61 (s, 3 H, OCH3), 3.82 (s, 3 H, OCH3), 6.87–6.94 (m, 2
H, CH), 7.05–7.12 (m, 1 H CH), 7.21–7.29 (m, 2 H, CH).
MS (EI, 70 eV): m/z (%) = 274 (M+, 35Cl, 93), 243 (100), 207 (21),
13C NMR (75 MHz, CDCl3): d = 17.9, 21.0 (CH3), 52.1, 55.2
(OCH3), 113.8, 129.3, 129.6 (CH), 132.4, 132.6, 133.2, 134.0,
137.4, 137.6, 159.1 (C), 169.9 (CO2Me).
MS (EI, 70 eV): m/z (%) = 304 (M+, 35Cl, 100), 272 (41), 238 (33).
HRMS (EI): m/z (M+, 35Cl) calcd for C17H17ClO3: 304.08607;
180 (37), 165 (43).
HRMS (EI): m/z (M+, 35Cl) calcd for C16H15ClO2: 274.0755; found:
274.0750.
Fluorenones 7 and 11; General Procedure
Compound 6 was dissolved in concd H2SO4 and the mixture was
stirred at 20 °C for 1 h. The mixture was poured into ice water and
extracted with Et2O (3 ×). The combined organic layers were dried
(Na2SO4), filtered, and the filtrate was concentrated in vacuo to give
7. Compounds 7a–i,x–z,aa–ah, and 11 were purified by precipita-
tion and washing with Et2O. The other fluorenones were purified by
chromatography.
found: 304.08598.
Methyl 4,4¢-Dichloro-3,5-dimethylbiphenyl-2-carboxylate (6v)
Starting with triflate 4h (0.270 g, 0.8 mmol), 4-chlorophenylboron-
ic acid (0.158 g, 1.0 mmol), K3PO4 (0.265 g, 1.3 mmol), Pd(PPh3)4
(0.027 g, 0.02 mmol, 3 mol%), and 1,4-dioxane (2.0 mL), 6v was
isolated as a colorless solid; yield: 0.218 g (90%); mp 98–99 °C;
Rf = 0.27 (n-heptane–EtOAc, 20:1).
7-Methoxy-1,2,3-trimethyl-9H-fluoren-9-one (7a)
Starting with 6a (0.097 g, 0.34 mmol) and concd H2SO4 (4.1 mL),
7a was isolated as a yellow solid; yield: 0.073 g (85%); mp 135–136
°C.
IR (KBr): 2949 (m), 2922 (m), 2856 (m), 1722 (s), 1489 (m), 1436
(m), 1381 (m), 1274 (s), 1233 (m), 1105 cm–1 (m).
1H NMR (250 MHz, CDCl3): d = 2.40 (s, 3 H, CH3), 2.42 (br s, 3 H,
CH3), 3.60 (s, 3 H, OCH3), 7.07 (s, 1 H, CH), 7.21–7.29 (m, 2 H
CH), 7.30–7.38 (m, 2 H, CH).
13C NMR (75 MHz, CDCl3): d = 18.0, 21.0 (CH3), 52.1 (OCH3),
128.5, 129.4, 129.5 (CH), 132.5, 133.6, 133.7, 134.8, 136.6, 137.9,
138.5 (C), 169.5 (CO2Me).
IR (KBr): 3437 (br, m), 2952 (w), 2937 (w), 2833 (w), 1696 (s),
1601 (s), 1482 (m), 1462 (s), 1433 (s), 1372 (w), 1289 (s), 1259 (m),
1222 (s), 1200 (w), 1192 (w), 1069 (w), 1031 cm–1 (w).
1H NMR (500 MHz, CDCl3): d = 2.13 (s, 3 H, CH3), 2.29 (s, 3 H,
CH3), 2.57 (s, 3 H, CH3), 3.83 (s, 3 H, OCH3), 6.91 (dd, 3J = 8.2 Hz,
4J = 2.5 Hz, 1 H, CH), 7.03 (s, 1 H, CH), 7.12 (d, 4J = 2.5 Hz, 1 H,
CH), 7.29 (d, 3J = 8.2 Hz, 1 H, CH).
13C NMR (126 MHz, CDCl3): d = 13.8, 14.6, 15.4 (CH3), 55.7
(OCH3), 108.9, 119.1, 119.7, 120.4 (CH), 129.3, 135.9, 136.3,
136.6, 138.7, 142.7, 143.2, 160.5 (C), 195.2 (C=O).
MS (EI, 70 eV): m/z (%) = 308 (M+, 35Cl, 86), 277 (100), 241 (39).
HRMS (EI): m/z (M+, 35Cl) calcd for C16H14Cl2O2: 308.03654;
found: 308.03617.
Methyl 4-Chloro-3,5-dimethyl-4¢-(trifluoromethyl)biphenyl-2-
carboxylate (6w)
MS (EI, 70 eV): m/z (%) = 252 (M+, 100), 237 (67), 165 (48).
Starting with triflate 4h (0.236 g, 0.68 mmol), 4-(trifluorometh-
yl)phenylboronic acid (0.167 g, 0.9 mmol), K3PO4 (0.231 g,
1.1 mmol), Pd(PPh3)4 (0.023 g, 0.02 mmol, 3 mol%), and 1,4-diox-
HRMS (EI): m/z [M]+ calcd for C17H16O2: 252.1145; found:
252.1143.
Synthesis 2009, No. 3, 445–463 © Thieme Stuttgart · New York

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Synthesis of Biaryls, Fluorenones, Cyclopenta[def]phenanthren-4-ones, and Benzophenones
457
Anal. Calcd for C17H16O2 (252.31): C, 80.93; H, 6.39. Found: C,
80.90; H, 6.51.
3,7-Dimethyl-1-phenyl-9H-fluoren-9-one (7f)
Starting with 6f (0.035 g, 0.11 mmol) and concd H2SO4 (1.3 mL),
7f was isolated as a orange oil; yield: 0.025 g (80%).
1,2,3-Trimethyl-9H-fluoren-9-one (7b)
IR (KBr): 3436 (br, s), 3433 (s), 2923 (w), 1706 (s), 1607 (m), 1468
(w), 1428 (w), 1279 (w), 1219 (m), 1143 (m), 1091 (w), 1035 cm–1
(w).
1H NMR (250 MHz, CDCl3): d = 2.36 (s, 3 H, CH3), 2.43 (s, 3 H,
CH3), 6.97 (br s, 1 H, CH), 7.28 (br s, 2 H, CH), 7.36 (br s, 1 H, CH),
7.39 (br s, 1 H, CH), 7.40–7.45 (m, 3 H, CH), 7.49–7.53 (m, 2 H,
CH).
13C NMR (CDCl3, 63 MHz): d = 21.4, 22.0 (CH3), 119.6, 119.9,
124.6, 127.8, 128.1, 129.1, 131.6, 134.7 (CH), 134.8, 137.6, 140.8,
142.1, 143.7, 145.2, 146.1, 148.2 (C), 195.5 (C=O).
Starting with 6b (0.028 g, 0.11 mmol) and concd H2SO4 (1.3 mL),
7b was isolated as a yellow solid; yield: 0.023 g (94%); mp 167–
168 °C.
IR (KBr): 3439 (br, m), 3382 (m), 3058 (w), 3050 (w), 2977 (w),
2919 (m), 2856 (w), 1701 (s), 1612 (s), 1598 (s), 1468 (w), 1452
(m), 1416 (w), 1372 (m), 1297 (w), 1257 (w), 1199 (w), 1177 (m),
1132 (w), 1087 cm–1 (w).
1H NMR (250 MHz, CDCl3): d = 2.18 (s, 3 H, CH3), 2.34 (s, 3 H,
CH3), 2.61 (s, 3 H, CH3), 7.17 ( br s, 1 H, CH), 7.20–7.24 (m, 1 H,
CH), 7.40–7.43 (m, 2 H, CH), 7.56–7.60 (m, 1 H, CH).
13C NMR (75 MHz, CDCl3): d = 13.8, 14.8, 21.7 (CH3), 119.4,
119.7, 123.7, 128.2 (CH), 129.1 (C), 134.0 (CH), 134.8, 137.3,
138.6, 142.3, 143.1, 143.7 (C), 195.4 (C=O).
MS (EI, 70 eV): m/z (%) = 284 (M+, 63), 283 (100), 239 (18), 141
(13), 134 (19).
HRMS (EI): m/z [M – H] calcd for C21H15O: 283.11174; found:
283.11180.
MS (EI, 70 eV): m/z (%) = 222 (M+, 100), 207 (66), 179 (52), 178
(58), 165 (23), 152 (22).
HRMS (EI): m/z [M]+ calcd for C16H14O: 222.1039; found:
222.1036.
7-Methoxy-1,3-dimethyl-9H-fluoren-9-one (7g)
Starting with 6g (0.049 g, 0.18 mmol) and concd H2SO4 (2.2 mL),
7g was isolated as a yellow solid; yield: 0.039 g (91%); mp 113–114
°C.
Anal. Calcd for C16H14O (222.28): C, 86.45; H, 6.35. Found: C,
86.19; H, 6.54.
IR (KBr): 3439 (br, m), 3391 (m), 2923 (m), 2853 (m), 1728 (w),
1703 (s), 1606 (m), 1590 (m), 1491 (m), 1471 (m), 1434 (m), 1373
(w), 1293 (s), 1268 (m), 1225 (m), 1199 (m), 1145 (w), 1091 (w),
1021 cm–1 (m).
1H NMR (250 MHz, CDCl3): d = 2.34 (s, 3 H, CH3), 2.55 (s, 3 H,
CH3), 3.84 (s, 3 H, OCH3), 6.75–6.76 (m, 1 H, CH), 6.94 (dd,
3J = 8.2 Hz, 4J = 2.4 Hz, 1 H, CH), 7.05–7.06 (m, 1 H, CH), 7.15 (d,
4J = 2.4 Hz, 1 H, CH), 7.35 (d, 3J = 8.2 Hz, 1 H, CH).
13C NMR (63 MHz, CDCl3): d = 17.7, 21.9 (CH3), 55.7 (OCH3),
108.8, 118.2, 119.6, 120.8, 131.1 (CH), 136.3, 139.4, 145.2, 148.0,
160.7, 183.2 (C), 194.5 (C=O).
MS (EI, 70 eV): m/z (%) = 238 (M+, 100), 223 (48), 195 (11), 167
(12).
1,2,3,7-Tetramethyl-9H-fluoren-9-one (7c)
Starting with 6c (0.043 g, 0.16 mmol) and concd H2SO4 (1.9 mL),
7c was isolated as a yellow solid; yield: 0.034 g (90%); mp 151–152
°C.
IR (KBr): 3456 (br, m), 3384 (m), 3034 (m), 2921 (m), 2861 (m),
1703 (s), 1604 (s), 1591 (m), 1486 (m), 1456 (m), 1427 (m), 1374
(m), 1277 (m), 1221 (m), 1200 (m), 1144 (m), 1099 (w), 1069 (w),
1007 cm–1 (w).
1H NMR (500 MHz, CDCl3): d = 2.16 (s, 3 H, CH3), 2.32 (s, 3 H,
CH3), 2.35 (s, 3 H, CH3), 2.59 (s, 3 H, CH3), 7.11 (s, 1 H, CH), 7.21
(br d, 3J = 7.5 Hz, 1 H, CH), 7.30 (d, 3J = 7.5 Hz, 1 H, CH), 7.38 (br
s, 1 H, CH).
13C NMR (126 MHz, CDCl3): d = 13.8, 14.7, 21.3, 21.7 (CH3),
119.2, 119.4, 124.4 (CH), 129.3 (C), 134.5 (CH), 135.2, 136.7,
138.4, 138.5, 141.1, 142.5, 143.0 (C), 195.7 (C=O).
MS (EI, 70 eV): m/z (%) = 237 (36), 236 (M+, 100), 221 (88), 193
(47), 178 (34).
HRMS (EI): m/z [M]+ calcd for C16H14O2: 238.0988; found:
238.0993.
1,3-Dimethyl-9H-fluoren-9-one (7h)
Starting with 6h (0.031 g, 0.13 mmol) and concd H2SO4 (1.6 mL),
7h was isolated as a yellow solid; yield: 0.023 g (85%); mp 108–
109 °C.
HRMS (EI): m/z [M]+ calcd for C17H16O: 236.1196; found:
236.1191.
IR (KBr): 3440 (br, m), 2918 (w), 1699 (s), 1616 (m), 1602 (m),
1592 (m), 1458 (w), 1375 (w), 1293 (w), 1173 (w), 1134 cm–1 (w).
3-Methyl-1-phenyl-9H-fluoren-9-one (7e)
Starting with 6e (0.036 g, 0.12 mmol) and concd H2SO4 (1.5 mL),
7e was isolated as a yellow solid; yield: 0.030 g (92%); mp 83–85
°C.
1H NMR (250 MHz, CDCl3): d = 2.36 (s, 3 H, CH3), 2.57 (s, 3 H,
CH3), 6.83–6.84 (m, 1 H, CH), 7.16 (m, 1 H, CH), 7.22–7.29 (m, 1
H, CH), 7.40–7.49 (m, 2 H, CH), 7.60 (dt, 3J = 7.3 Hz, 4J = 1.1 Hz,
1 H, CH).
IR (KBr): 3437 (br, m), 3395 (m), 3056 (m), 3029 (m), 2921 (m),
1709 (s), 1613 (s), 1604 (s), 1573 (m), 1467 (m), 1456 (w), 1290
(w), 1275 (w), 1183 (m), 1127 (m), 1076 (w), 1030 cm–1 (w).
13C NMR (75 MHz, CDCl3): d = 17.7, 21.9 (CH3), 118.9, 119.8,
123.7, 128.8, 132.3, 134.0 (CH), 134.9, 139.4, 143.7, 145.0, 145.2,
181.3 (C), 194.7 (C=O).
MS (EI, 70 eV): m/z (%) = 208 (M+, 100), 193 (14), 179 (10), 178
(13), 165 (30).
HRMS (EI): m/z [M]+ calcd for C15H12O: 208.0883; found:
208.0879.
1H NMR (250 MHz, CDCl3): d = 2.45 (s, 3 H, CH3), 7.00–7.01 (m,
3
4
1 H, CH), 7.27 (dt, J = 7.3 Hz, J = 1.2 Hz, 1 H, CH), 7.33–7.34
(m, 1 H, CH), 7.40–7.58 (m, 8 H, CH).
13C NMR (75 MHz, CDCl3): d = 22.0 (CH3), 119.8, 120.1, 123.9,
127.8, 128.1, 128.2, 128.3, 129.0, 132.0, 134.2, 134.8 (CH), 137.5,
139.3, 140.6, 142.2, 143.4, 145.2, 145.9 (C), 192.7 (C=O).
MS (EI, 70 eV): m/z (%) = 270 (M+, 56), 269 (100), 239 (18), 134
(12), 120 (10).
1,3,7-Trimethyl-9H-fluoren-9-one (7i)
Starting with 6i (0.086 g, 0.34 mmol) and concd H2SO4 (4.1 mL), 7i
was isolated as a yellow solid; yield: 0.069 g (91%); mp 121–122
°C.
HRMS (EI): m/z [M]+ calcd for C20H14O: 270.10392; found:
270.10329.
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S. Reim et al.
PAPER
IR (KBr): 3439 (br, w), 3383 (w), 3022 (w), 2919 (m), 2856 (w),
1699 (s), 1608 (s), 1592 (m), 1491 (w), 1456 (w), 1373 (w), 1283
(m), 1219 (w), 1187 (w), 1155 (m), 1115 (w), 1090 (w), 1035 cm–1
(w).
IR (KBr): 2933 (s), 2857 (m), 1695 (s), 1616 (m), 1598 (s), 1487
(m), 1459 (m), 1438 (m), 1287 (m), 1203 cm–1 (m).
1H NMR (250 MHz, CDCl3): d = 1.68–1.89 (m, 4 H, CH2), 2.24 (s,
3 H, CH3), 2.34 (s, 3 H, CH3), 2.58 (t, 3J = 6.0 Hz, 2 H, CH2), 3.16
1H NMR (500 MHz, CDCl3): d = 2.34 (s, 3 H, CH3), 2.35 (s, 3 H,
(t, J = 6.0 Hz, 2 H, CH2), 7.08 (s, 1 H, CH), 7.14–7.39 (m, 3 H,
3
CH3), 2.55 (s, 3 H, CH3), 6.79 (br s, 1 H, CH), 7.10 (br s, 1 H, CH),
CH).
3
3
7.22 (br d, J = 7.5 Hz, 1 H, CH), 7.33 (d, J = 7.5 Hz, 1 H, CH),
13C NMR (75 MHz, CDCl3): d = 20.7, 21.3 (CH3), 21.9, 22.8, 26.1,
27.1 [(CH2)4], 119.2, 119.2, 124.2, 134.2 (CH), 128.5, 135.1, 137.7,
138.4, 139.2, 141.2, 142.6, 143.6 (C), 195.5 (C=O).
MS (EI, 70 eV): m/z (%) = 262 (M+, 91), 247 (66), 202 (9).
HRMS (EI): m/z [M]+ calcd for C19H18O: 262.13522; found:
7.40 (br s, 1 H, CH).
13C NMR (126 MHz, CDCl3): d = 17.7, 21.3, 21.9 (CH3), 118.6,
119.6, 124.3 (CH), 128.8 (C), 131.8, 134.4 (CH), 135.2, 138.9,
139.2, 141.1, 144.9, 145.4 (C), 194.9 (C=O).
MS (EI, 70 eV): m/z (%) = 223 (23), 222 (M+, 100), 179 (34).
HRMS (EI): m/z [M]+ calcd for C16H14O: 222.1039; found:
262.13506.
222.1035.
2-Ethyl-7-methoxy-1,3-dimethyl-9H-fluoren-9-one (7m)
Starting with 6m (0.090 g, 0.3 mmol) and concd H2SO4 (3.6 mL),
7m was isolated after column chromatography (silica gel, toluene)
as an orange solid; yield: 0.074 g (92%); mp 133–134 °C; Rf = 0.68
(toluene–EtOAc, 10:1).
9-Methoxy-5-methyl-1,2,3,4-tetrahydro-11H-benzo[a]fluoren-
11-one (7j)
Starting with 6j (0.102 g, 0.33 mmol) and concd H2SO4 (4.0 mL),
7j was isolated after column chromatography (silica gel, n-heptane–
EtOAc, 10:1) as a yellow solid; yield: 0.056 g (61%); mp 149–150
°C; Rf = 0.35 (n-heptane–EtOAc, 10:1).
IR (KBr): 2964 (m), 2927 (m), 1868 (m), 1700 (s), 1602 (s), 1489
(m), 1457 (m), 1436 (m), 1377 (m), 1294 cm–1 (s).
3
1H NMR (250 MHz, CDCl3): d = 1.09 (t, J = 7.6 Hz, 3 H, CH3),
IR (KBr): 2942 (m), 2924 (m), 2868 (m), 2833 (m), 1698 (s), 1598
(s), 1486 (m), 1460 (s), 1436 (s), 1286 cm–1 (s).
1H NMR (250 MHz, CDCl3): d = 1.67–1.89 (m, 4 H, CH2), 2.23 (s,
3 H, CH3), 2.57 (t, 3J = 6.0 Hz, 2 H, CH2), 3.15 (t, 3J = 6.1 Hz, 2 H,
CH2), 3.83 (s, 3 H, OCH3), 6.90 (dd, 3J = 8.1 Hz, 4J = 2.4 Hz, 1 H,
3
2.34 (s, 3 H, CH3), 2.61 (s, 3 H, CH3), 2.64 (q, J = 7.6 Hz, 2 H,
CH2), 3.83 (s, 3 H, OCH3), 6.91 (dd, 3J = 8.2 Hz, 4J = 2.5 Hz, 1 H,
4
CH), 7.04 (s, 1 H, CH), 7.13 (d, J = 2.5 Hz, 1 H, CH), 7.30 (d,
3J = 8.2 Hz, 1 H, CH).
13C NMR (75 MHz, CDCl3): d = 13.1, 13.3, 20.8 (CH3), 21.7 (CH2),
55.7 (OCH3), 108.2, 119.6, 116.7, 120.4 (CH), 129.6, 136.2, 136.6,
138.2, 141.8, 142.8, 142.8, 160.4 (C), 195.2 (C=O).
MS (EI, 70 eV): m/z (%) = 266 (M+, 52), 252 (18), 251 (100), 208
(13), 165 (11).
HRMS (EI): m/z [M]+ calcd for C18H18O2: 266.13013; found:
266.12994.
4
CH), 7.03 (s, 1 H, CH), 7.11 (d, J = 2.4 Hz, 1 H, CH), 7.29 (d,
3J = 8.1 Hz, 1 H, CH).
13C NMR (75 MHz, CDCl3): d = 20.7 (CH3), 22.0, 22.8, 26.1, 27.0
[(CH2)4], 55.7 (OCH3), 108.9, 118.9, 119.4, 120.4 (CH), 128.6,
136.0, 136.4, 136.6, 139.4, 142.9, 143.8, 160.4 (C), 195.0 (C=O).
MS (EI, 70 eV): m/z (%) = 278 (M+, 100), 279 (18), 263 (66), 235
(15), 189 (15).
HRMS (EI): m/z [M]+ calcd for C19H18O2: 278.13013; found:
278.12967.
Anal. Calcd for C18H18O2 (266.33): C, 81.17; H, 6.81. Found: C,
80.78; H, 6.79.
2-Ethyl-1,3-dimethyl-9H-fluoren-9-one (7n)
5-Methyl-1,2,3,4-tetrahydro-11H-benzo[a]fluoren-11-one (7k)
Starting with 6k (0.081 g, 0.29 mmol) and concd H2SO4 (3.5 mL),
7k was isolated after column chromatography (silica gel, n-hep-
tane–EtOAc, 10:1) as a yellow solid; yield: 0.066 g (91%); mp 95–
97 °C; Rf = 0.47 (n-heptane–EtOAc, 10:1).
Starting with 6n (0.070 g, 0.26 mmol) and concd H2SO4 (3.1 mL),
7n was isolated after column chromatography (silica gel, n-hep-
tane–EtOAc, 10:1) as a yellow solid; yield: 0.056 g (91%); mp 112–
113 °C; Rf = 0.44 (n-heptane–EtOAc, 5:1).
IR (Nujol): 1703 (s), 1611 (m), 1599 (m), 1292 (m), 1217 (w), 1177
(m), 1130 (m), 1083 cm–1 (m).
IR (KBr): 2938 (br, m), 2870 (m), 1696 (s), 1609 (m), 1598 (s),
1464 (m), 1451 (m), 1408 (m), 1383 (w), 1299 cm–1 (m).
1H NMR (250 MHz, CDCl3): d = 1.68–1.90 (m, 4 H, CH2), 2.24 (s,
3 H, CH3), 2.58 (t, 3J = 6.0 Hz, 2 H, CH2), 3.17 (t, 3J = 6.0 Hz, 2 H,
CH2), 7.11 (br s, 1 H, CH), 7.14–7.27 (m, 1 H, CH), 7.33–7.44 (m,
2 H, CH), 7.50–7.59 (m, 1 H, CH).
13C NMR (75 MHz, CDCl3): d = 20.7 (CH3), 21.9, 22.8, 26.1, 27.2
[(CH2)4], 119.4, 119.5, 123.5, 128.3 (CH), 128.4 (C), 133.9 (CH),
134.8, 137.3, 139.3, 142.4, 143.7, 143.9 (C), 195.2 (C=O).
MS (EI, 70 eV): m/z (%) = 248 (M+, 91), 233 (100), 215 (24), 202
(22), 189 (22).
HRMS (EI): m/z [M]+ calcd for C18H16O: 248.11957; found:
248.11892.
3
1H NMR (250 MHz, CDCl3): d = 1.10 (t, J = 7.6 Hz, 3 H, CH3),
3
2.37 (s, 3 H, CH3), 2.63 (s, 3 H, CH3), 2.66 (q, J = 7.6 Hz, 2 H,
CH2), 7.15 (s, 1 H, CH), 7.16–7.12 (m, 1 H, CH), 7.35–7.45 (m, 2
H, CH), 7.52–7.62 (m, 1 H, CH).
13C NMR (63 MHz, CDCl3): d = 13.1, 13.3, 20.8 (CH3), 21.8 (CH2),
119.4, 120.2, 123.7, 128.3, 134.0 (CH), 139.4, 134.8, 138.1, 142.4,
142.6, 143.1, 143.6 (C), 195.4 (C=O).
MS (EI, 70 eV): m/z (%) = 236 (M+, 44), 222 (18), 221 (100), 178
(18).
HRMS (EI): m/z [M]+ calcd for C17H16O: 236.11957; found:
236.11918.
2-Ethyl-1,3,7-trimethyl-9H-fluoren-9-one (7o)
5,9-Dimethyl-1,2,3,4-tetrahydro-11H-benzo[a]fluoren-11-one
(7l)
Starting with 6l (0.100 g, 0.34 mmol) and concd H2SO4 (4.1 mL), 7l
was isolated after column chromatography (silica gel, n-heptane–
EtOAc, 10:1) as a yellow solid; yield: 0.079 g (89%); mp 203–204
°C; Rf = 0.42 (n-heptane–EtOAc, 5:1).
Starting with 6o (0.082 g, 0.29 mmol) and concd H2SO4 (3.5 mL),
7o was isolated after column chromatography (silica gel, n-hep-
tane–EtOAc, 10:1) as a yellow solid; yield: 0.065 g (89%); mp 164–
165 °C; Rf = 0.45 (n-heptane–EtOAc, 5:1).
IR (KBr): 2965 (m), 2923 (m), 2867 (m), 1700 (s), 1616 (m), 1605
(m), 1486 (m), 1460 (br, m), 1375 (m), 1280 cm–1 (m).
Synthesis 2009, No. 3, 445–463 © Thieme Stuttgart · New York

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Synthesis of Biaryls, Fluorenones, Cyclopenta[def]phenanthren-4-ones, and Benzophenones
459
3
1H NMR (250 MHz, CDCl3): d = 1.10 (t, J = 7.6 Hz, 3 H, CH3),
2.34 (s, 3 H, CH3), 2.35 (s, 3 H, CH3), 2.62 (s, 3 H, CH3), 2.65 (q,
3J = 7.6 Hz, 2 H, CH2), 7.10 (s, 1 H, CH), 7.16–7.41 (m, 3 H, CH).
13C NMR (75 MHz, CDCl3): d = 14.7, 15.1 (CH3), 24.8, 29.4 (CH2),
55.7 (OCH3), 108.3, 117.1, 119.6, 120.8, 128.4 (CH), 128.4, 136.4,
136.7, 145.9, 146.2, 151.8, 160.7 (C), 194.3 (C=O).
13C NMR (75 MHz, CDCl3): d = 13.1, 13.3, 20.8, 21.3 (CH3), 21.8
(CH2), 119.2, 119.9, 124.4, 134.5 (CH), 129.5, 135.1, 138.0, 138.4,
141.0, 142.5, 142.6 (C), 195.6 (C=O).
MS (EI, 70 eV): m/z (%) = 266 (M+, 100), 251 (36), 237 (25), 165
(16).
Anal. Calcd for C18H18O2 (266.33): C, 81.17; H, 6.81. Found: C,
80.76; H, 6.89.
MS (EI, 70 eV): m/z (%) = 250 (M+, 38), 235 (100), 236 (17), 191
(10).
6,8-Diethyl-1,2,3-trimethoxy-9H-fluoren-9-one (7s)
Starting with 6s (0.093 g, 0.26 mmol) and concd H2SO4 (3.1 mL),
7s was isolated after column chromatography (silica gel, toluene–
EtOAc, 4:1) as a yellow oil; yield: 0.077 g (91%); Rf = 0.50 (tolu-
ene–EtOAc, 2:1).
HRMS (EI): m/z [M]+ calcd for C18H18O: 250.13522; found:
250.13538.
1,3-Diethyl-9H-fluoren-9-one (7p)
Starting with 6p (0.107 g, 0.4 mmol) and concd H2SO4 (4.8 mL), 7p
was isolated after column chromatography (silica gel, n-heptane–
EtOAc, 5:1) as a yellow solid; yield: 0.087 g (92%); mp 46–47 °C;
Rf = 0.50 (n-heptane–EtOAc, 5:1).
IR (Nujol): 1690 (m), 1596 (m), 1308 (m), 1240 (m), 1198 (w),
1124 (m), 1074 (w), 1045 cm–1 (m).
3
1H NMR (250 MHz, CDCl3): d = 1.23 (t, J = 7.5 Hz, 3 H, CH3),
IR (neat): 3052 (m), 2967 (m), 2932 (m), 2872 (m), 1704 (s), 1613
(s), 1603 (s), 1589 (s), 1469 (m), 1460 cm–1 (m).
1.27 (t, 3J = 7.6 Hz, 3 H, CH3), 2.65 (q, 3J = 7.6 Hz, 2 H, CH2), 3.01
(q, 3J = 7.5 Hz, 2 H, CH2), 3.85 (s, 3 H, OCH3), 3.98 (s, 3 H, OCH3),
4.09 (s, 3 H, OCH3), 6.81 (s, 1 H, CH), 6.85 (br s, 1 H, CH), 7.10
(br s, 1 H, CH).
3
1H NMR (250 MHz, CDCl3): d = 1.25 (t, J = 7.6 Hz, 3 H, CH3),
1.28 (t, 3J = 7.5 Hz, 3 H, CH3), 2.66 (q, 3J = 7.6 Hz, 2 H, CH2), 3.03
(q, 3J = 7.5 Hz, 2 H, CH2), 6.85–6.93 (m, 1 H, CH), 7.13–7.29 (m,
2 H, CH), 7.36–7.63 (m, 3 H, CH).
13C NMR (63 MHz, CDCl3): d = 14.9, 15.2 (CH3), 24.5, 29.3 (CH2),
56.4, 61.4, 62.0 (OCH3), 99.5, 116.9, 129.5 (CH), 118.9, 128.9,
141.5, 142.0, 144.0, 145.4, 150.6, 153.1, 158.7 (C), 191.5 (C=O).
MS (EI, 70 eV): m/z (%) = 326 (M+, 98), 311 (100), 293 (29), 283
(22), 253 (34).
13C NMR (75 MHz, CDCl3): d = 14.7, 15.3 (CH3), 24.7, 29.4 (CH2),
117.7, 119.7, 123.7, 128.7, 129.5, 134.0 (CH), 128.3, 134.9, 143.8,
145.5, 146.1, 151.6 (C), 194.5 (C=O).
MS (EI, 70 eV): m/z (%) = 236 (M+, 100), 221 (41), 207 (71), 178
HRMS (EI): m/z [M]+ calcd for C20H22O4: 326.15126; found:
(33), 165 (13).
326.15071.
HRMS (EI): m/z [M]+ calcd for C17H16O: 236.11957; found:
236.11902.
4-Ethyl-7-methoxy-1,2,3-trimethyl-9H-fluoren-9-one (7t)
Starting with 6t (0.084 g, 0.27 mmol) and concd H2SO4 (3.2 mL),
7t was isolated after column chromatography (silica gel, toluene–
EtOAc, 50:1) as an orange solid; yield: 0.070 g (92%); mp 160–161
°C; Rf = 0.73 (toluene–EtOAc, 10:1).
1,3-Diethyl-7-methyl-9H-fluoren-9-one (7q)
Starting with 6q (0.110 g, 0.39 mmol) and concd H2SO4 (4.7 mL),
7q was isolated after column chromatography (silica gel, toluene)
as a orange solid; yield: 0.091 g (93%); mp 88–89 °C; Rf =
0.83 (toluene).
IR (KBr): 2975 (m), 2956 (m), 2927 (m), 2836 (m), 1694 (s), 1622
(m), 1590 (m), 1574 (m), 1483 (s), 1438 cm–1 (m).
3
IR (Nujol): 1698 (m), 1607 (m), 1582 (m), 1281 (m), 1218 (w),
1185 (w), 1155 (m), 1088 (w), 1060 cm–1 (w).
1H NMR (250 MHz, CDCl3): d = 1.24 (t, J = 7.6 Hz, 3 H, CH3),
2.17 (s, 3 H, CH3), 2.26 (s, 3 H, CH3), 2.59 (s, 3 H, CH3), 2.90 (q,
3J = 7.6 Hz, 2 H, CH2), 3.84 (s, 3 H, OCH3), 6.92 (dd, 3J = 8.4 Hz,
3
1H NMR (250 MHz, CDCl3): d = 1.24 (t, J = 7.6 Hz, 3 H, CH3),
4J = 2.6 Hz, 1 H, CH), 7.17 (d, J = 2.6 Hz, 1 H, CH), 7.48 (d,
4
1.27 (t, 3J = 7.6 Hz, 3 H, CH3), 2.35 (s, 3 H, CH3), 2.65 (q,
3J = 7.6 Hz, 2 H, CH2), 3.02 (q, 3J = 7.6 Hz, 2 H, CH2), 6.82–6.89
(m, 1 H, CH), 7.14 (br s, 1 H, CH), 7.19–7.27 (m, 1 H, CH), 7.30–
7.42 (m, 2 H, CH).
3J = 8.4 Hz, 1 H, CH).
13C NMR (75 MHz, CDCl3): d = 13.4, 13.9, 15.6, 16.0 (CH3), 22.7
(CH2), 55.6 (OCH3), 108.8, 119.5, 123.7 (CH), 129.4, 135.4, 136.3,
136.5, 136.7, 137.3, 140.1, 142.0, 159.6 (C), 195.4 (C=O).
13C NMR (75 MHz, CDCl3): d = 14.8, 15.2, 21.4 (CH3), 24.6, 29.3
(CH2), 117.5, 119.6, 124.4, 129.1, 134.5 (CH), 128.4, 135.2, 138.9,
141.2, 145.7, 146.0, 151.5 (C), 194.8 (C=O).
MS (EI, 70 eV): m/z (%) = 280 (M+, 84), 266 (27), 265 (100), 222
(16), 178 (18).
MS (EI, 70 eV): m/z (%) = 250 (M+, 100), 236 (22), 235 (26), 207
HRMS (EI): m/z [M]+ calcd for C19H20O2: 280.14578; found:
(14), 178 (22).
280.14588.
HRMS (EI): m/z [M]+ calcd for C18H18O: 250.13522; found:
250.13487.
2-Chloro-7-methoxy-1,3-dimethyl-9H-fluoren-9-one (7u)
Starting with 6u (0.146 g, 0.48 mmol) and concd H2SO4 (5.8 mL),
7u was isolated after column chromatography (silica gel, toluene–
EtOAc, 30:1) as a yellow solid; yield: 0.118 g (90%); mp 141–143
°C; Rf = 0.75 (toluene–EtOAc, 10:1).
1,3-Diethyl-7-methoxy-9H-fluoren-9-one (7r)
Starting with 6r (0.140 g, 0.47 mmol) and concd H2SO4 (5.6 mL),
7r was isolated after column chromatography (silica gel, toluene) as
an orange solid; yield: 0.100 g (80%); mp 45–46 °C; Rf
0.71 (toluene–EtOAc, 10:1).
=
IR (KBr): 2951 (m), 2925 (m), 1711 (s), 1603 (m), 1492 (m), 1455
(m), 1434 (m), 1380 (m), 1293 (m), 1261 cm–1 (m).
IR (Nujol): 1709 (m), 1608 (m), 1589 (m), 1284 (m), 1274 (m),
1233 (m), 1190 (w), 1028 cm–1 (m).
1H NMR (250 MHz, CDCl3): d = 2.40 (s, 3 H, CH3), 2.65 (s, 3 H,
CH3), 3.84 (s, 3 H, OCH3), 6.94 (dd, 3J = 8.2 Hz, 4J = 2.4 Hz, 1 H,
CH), 7.11 (br s, 1 H, CH), 7.13 (d, 4J = 2.4 Hz, 1 H, CH), 7.31 (d,
3J = 8.2 Hz, 1 H, CH).
13C NMR (63 MHz, CDCl3): d = 14.3, 21.9 (CH3), 55.7 (OCH3),
109.1, 119.5, 120.1, 120.9 (CH), 135.1, 135.5, 136.3, 138.0, 142.6,
143.1, 147.8, 160.8 (C), 193.8 (C=O).
3
1H NMR (250 MHz, CDCl3): d = 1.23 (t, J = 7.5 Hz, 3 H, CH3),
1.26 (t, 3J = 7.6 Hz, 3 H, CH3), 2.63 (q, 3J = 7.6 Hz, 2 H, CH2), 3.00
(q, 3J = 7.5 Hz, 2 H, CH2), 3.84 (s, 3 H, OCH3), 6.81 (br s, 1 H, CH),
6.93 (dd, 3J = 8.1 Hz, 4J = 2.4 Hz, 1 H, CH), 7.07 (br s, 1 H, CH),
7.14 (d, 4J = 2.4 Hz, 1 H, CH), 7.35 (d, 3J = 8.1 Hz, 1 H, CH).
Synthesis 2009, No. 3, 445–463 © Thieme Stuttgart · New York

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S. Reim et al.
PAPER
MS (EI, 70 eV): m/z (%) = 272 (M+, 35Cl, 100), 257 (60), 201 (28),
165 (47).
HRMS (EI): m/z (M+, 35Cl) calcd for C16H13ClO2: 272.05986;
found: 272.05936.
IR (neat): 3339 (s), 2355 (m), 2923 (m), 1675 (s), 1627 (s), 1602 (s),
1587 (m), 1457 (m), 1334 (m), 1295 (m), 1238 (m), 1207 (m), 1172
cm–1 (m).
1H NMR (300 MHz, CDCl3): d = 2.35 (s, 3 H, CH3), 2.52 (s, 3 H,
CH3), 6.54 (s, 1 H, CH), 6.89 (s, 1 H, CH), 7.13–7.23 (m, 2 H, CH),
7.46 (d, 3J = 7.1 Hz, 1 H, CH), 8.60 (s, 1 H, OH).
13C NMR (75 MHz, CDCl3): d = 20.1, 22.6 (CH3), 115.5 (C), 117.5,
121.5, 128.7 (CH), 134.1, 135.1 (C), 137.0 (CH), 141.6, 144.7,
149.1 (C), 157.5 (COH), 196.1 (C=O).
MS (EI, 70 eV): m/z (%) = 224 (M+, 100), 195 (17), 181 (37), 165
(16), 152 (20).
HRMS (EI): m/z [M]+ calcd for C15H12O2: 224.08318; found:
224.083191.
2,7-Dichloro-1,3-dimethyl-9H-fluoren-9-one (7v)
Starting with 6v (0.139 g, 0.45 mmol) and concd H2SO4 (5.4 mL),
7v was isolated after column chromatography (silica gel, toluene) as
a yellow solid; yield: 0.111 g (89%); mp 181–182 °C; Rf =
0.83 (toluene).
IR (KBr ): 2955 (w), 2923 (w), 1705 (s), 1609 (m), 1598 (m), 1452
(m), 1430 (m), 1376 (m), 1245 (m), 1186 cm–1 (s).
1H NMR (250 MHz, CDCl3): d = 2.41 (br s, 3 H CH3), 2.64 (s, 3 H,
CH3), 7.16 (br s, 1 H, CH), 7.28–7.43 (m, 2 H, CH), 7.48–7.54 (m,
1 H, CH).
13C NMR (75 MHz, CDCl3): d = 14.4, 21.9 (CH3), 120.3, 120.9,
124.3, 133.9 (CH), 129.9, 135.0, 136.0, 136.6, 138.4, 141.0, 141.8,
143.0 (C), 192.3 (C=O).
7-Chloro-1-hydroxy-3-methyl-9H-fluoren-9-one (7z)
Starting with 3j (0.199 g, 0.72 mmol) and concd H2SO4 (8.9 mL),
7z was isolated as a yellow solid; yield: 0.146 g (83%), mp 165–167
°C.
MS (EI, 70 eV): m/z (%) = 276 (M+, 35Cl, 100), 241 (39), 176 (64).
HRMS (EI): m/z (M+, 35Cl) calcd for C15H10Cl2O: 276.01032;
IR (neat): 3402 (s), 2917 (w), 1680 (s), 1624 (s), 1604 (s), 1445 (m),
1391 (w), 1309 (s), 1257 (m), 1217 (m), 1190 (s), 1160 (m), 1098
cm–1 (m).
1H NMR (300 MHz, CDCl3): d = 2.35 (s, 3 H, CH3), 6.58 (br s, 1 H,
CH), 6.84 (br s, 1 H, CH), 7.40–7.41 (m, 2 H, CH), 7.56 (br s, 1 H,
CH), 8.22 (s, 1 H, OH).
found: 276.00990.
2-Chloro-1,3-dimethyl-7-(trifluoromethyl)-9H-fluoren-9-one
(7w)
Starting with 6w (0.075 g, 0.22 mmol) and concd H2SO4 (2.6 mL),
7w was isolated after column chromatography (silica gel, n-hep-
tane–EtOAc, 10:1) as a yellow solid; yield: 0.068 g (99%); mp 171–
172 °C; Rf = 0.66 (n-heptane–EtOAc, 10:1).
13C NMR (75 MHz, CDCl3): d = 22.4 (CH3), 114.4 (CH), 115.3 (C),
118.2, 121.7, 124.2, 133.8 (CH), 135.0, 136.4, 142.0, 143.0, 149.8
(C), 157.4 (COH), 194.0 (C=O).
MS (EI, 70 eV): m/z (%) = 244 (M+, 35Cl, 100), 181 (17), 152 (30).
HRMS (EI): m/z (M+, 35Cl) calcd for C14H9ClO2: 244.02856; found:
IR (KBr): 2987 (w), 2928 (w), 1657 (s), 1701 (s), 1623 (s), 1594
(m), 1455 (m), 1390 (m), 1327 (s), 1279 cm–1 (m).
1H NMR (250 MHz, CDCl3): d = 2.45 (s, 3 H, CH3), 2.68 (s, 3 H,
CH3), 7.29 (s, 1 H, CH), 7.49–7.57 (m, 1 H, CH), 7.66–7.76 (m, 1
H, CH), 7.82 (br s, 1 H, CH).
244.028552.
7-Chloro-2-hexyl-1-hydroxy-3-methyl-9H-fluoren-9-one (7aa)
Starting with 3k (0.249 g, 0.7 mmol) and concd H2SO4 (8.5 mL),
7aa was isolated as a yellowish solid; yield: 0.147 g (65%), mp 73–
75 °C.
13C NMR (75 MHz, CDCl3): d = 14.4, 22.0 (CH3), 120.0, 120.9
3
2
(CH), 121.0 (q, J = 3.8 Hz, CCH), 131.2 (q, J = 33 Hz, CCF3),
3
1
131.3 (q, J = 3.8 Hz, CCH), 123.7 (q, J = 272 Hz, CF3), 130.2,
IR (neat): 3349 (w), 2949 (m), 2918 (s), 2851 (m), 1676 (s), 1624
(m), 1596 (m), 1451 (m), 1384 (w), 1298 (m), 1258 (m), 1168 (s),
1115 (m), 1094 (m), 1031 cm–1 (w).
134.8, 137.6, 138.6, 141.2, 143.2, 145.9 (C), 192.8 (C=O).
MS (EI, 70 eV): m/z (%) = 310 (M+, 35Cl, 100), 275 (54), 247 (16),
91 (16).
1H NMR (250 MHz, CDCl3): d = 0.86–0.91 (m, 3 H, CH3), 1.24–
1.33 (m, 8 H, CH2), 2.32 (s, 3 H, CH3), 2.56–2.62 (m, 2 H, CH2),
6.81 (s, 1 H, CH), 7.35–7.41 (m, 2 H, CH), 7.53 (dd, 3J = 1.7 Hz,
5J = 0.6 Hz, 1 H, CH), 8.49 (s, 1 H, OH).
Anal. Calcd for C16H10ClF3O (310.70): C, 61.85; H, 3.24. Found: C,
61.74; H, 3.18.
2-Chloro-1,3-dimethyl-9H-fluoren-9-one (7x)
Starting with 6x (0.055 g, 0.2 mmol) and concd H2SO4 (2.5 mL), 7x
was isolated as a yellow solid; yield: 0.048 g (99%), mp 142 °C.
13C NMR (62 MHz, CDCl3): d = 14.1, 20.5 (CH3), 22.6, 25.4, 28.9,
29.5, 31.7 (CH2), 115.4, 121.5, 124.2 (CH), 127.6, 131.1 (C), 133.7
(CH), 134.4, 136.4, 139.7, 142.4, 146.9 (C), 156.1 (COH), 194.8
(C=O).
MS (EI, 70 eV): m/z (%) = 328 (M+, 35Cl, 21), 258 (55), 257 (100),
165 (19).
IR (KBr): 3381 (w), 2953 (w), 2920 (w), 2851 (w), 1703 (s), 1609
(m), 1597 (m), 1448 (m), 1186 (m), 1138 cm–1 (m).
1H NMR (300 MHz, CDCl3): d = 2.42 (s, 3 H, CH3), 2.67 (s, 3 H,
CH3), 7.20 (s, 1 H, CH), 7.24–7.60 (m, 4 H, CH).
13C NMR (75 MHz, CDCl3): d = 14.3, 21.9 (CH3), 119.8, 120.1,
124.0, 128.9 (CH), 130.0 (C), 134.3 (CH), 134.5, 136.3, 138.0,
142.5, 142.6, 142.9 (C), 193.9 (C=O).
MS (EI, 70 eV): m/z (%) = 242 (M+, 35Cl, 100), 207 (42), 178 (23).
HRMS (EI): m/z (M+, 35Cl) calcd for C15H11ClO: 242.0493; found:
HRMS (EI): m/z (M+, 35Cl) calcd for C20H21ClO2: 328.12246;
found: 328.122093.
5-Chloro-1-hydroxy-3-methyl-9H-fluoren-9-one (7ab)
Starting with 3l (0.219 g, 0.8 mmol) and concd H2SO4 (9.7 mL),
7ab was isolated as a colorless solid; yield: 0.145 g (75%), mp 145–
150 °C.
242.0490.
IR (neat): 3345 (s), 2918 (m), 1694 (s), 1619 (s), 1592 (s), 1445 (m),
1412 (w), 1377 (w), 1316 (m), 1296 (s), 1239 (m), 1168 cm–1 (s).
1H NMR (300 MHz, CDCl3): d = 2.36 (s, 3 H, CH3), 6.59 (s, 1 H,
CH), 7.19 (t, 3J = 7.6 Hz, 1 H, CH), 7.36–7.39 (m, 2 H, CH), 7.50
(d, 3J = 7.6 Hz, 1 H, CH), 8.44 (s, 1 H, OH).
1-Hydroxy-3,5-dimethyl-9H-fluoren-9-one (7y)
Starting with 3i (0.118 g, 0.46 mmol) and concd H2SO4 (5.7 mL),
7y was isolated as a yellow solid; yield: 0.070 mg (68%), mp 140–
145 °C.
Synthesis 2009, No. 3, 445–463 © Thieme Stuttgart · New York

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Synthesis of Biaryls, Fluorenones, Cyclopenta[def]phenanthren-4-ones, and Benzophenones
461
13C NMR (75 MHz, CDCl3): d = 22.7 (CH3), 115.2 (C), 118.3 (CH),
118.4 (C), 118.5, 122.1, 129.8, 135.7 (CH), 137.1, 140.1, 142.2,
149.7 (C), 157.5 (COH), 194.2 (C=O).
MS (EI, 70 eV): m/z (%) = 244 (M+, 35Cl, 100), 216 (17), 181 (32),
152 (31).
13C NMR (62 MHz, CDCl3): d = 10.6, 21.0 (CH3), 114.7 (C),
118.6, 119.7, 122.2 (CH), 125.9 (C), 129.7, 130.2 (CH), 137.3,
137.4, 147.5 (C), 155.9 (COH), 157.6 (d, 1J = 253.5 Hz, CF), 195.0
(C=O).
GC-MS (EI, 70 eV): m/z (%) = 242 (M+, 100), 227 (81), 213 (9),
199 (22), 183 (12), 170 (16).
HRMS (EI): m/z [M]+ calcd for C15H11FO2: 242.07376; found:
HRMS (EI): m/z (M+, 35Cl) calcd for C14H9ClO2: 244.02856; found:
244.028810.
242.07375.
5-Chloro-1-hydroxy-2,3-dimethyl-9H-fluoren-9-one (7ac)
Starting with 3m (31 mg, 0.1 mmol) and concd H2SO4 (1.5 mL),
7ac was isolated as a yellow solid; yield: 0.023 g (80%).
1H NMR (300 MHz, CDCl3): d = 2.04 (s, 3 H, CH3), 2.22 (s, 3 H,
CH3), 7.05–7.11 (m, 1 H, CH), 7.26–7.29 (m, 2 H, CH), 7.41 (dd,
3J = 7.3 Hz, 4J = 1.0 Hz, 1 H, CH), 8.65 (s, 1 H, OH).
13C NMR (75 MHz, CDCl3): d = 10.6, 21.2 (CH3), 115.0 (C), 118.8,
122.0 (CH), 126.3 (C), 129.3 (CH), 129.4 (C), 135.6 (CH), 136.9,
138.9, 140.4, 147.3 (C), 156.0 (COH), 194.8 (C=O).
GC-MS (EI, 70 eV): m/z (%) = 258 (M+, 35Cl, 100), 243 (59), 215
(12), 195 (8), 176 (11), 165 (22), 152 (14).
HRMS (EI): m/z (M+, 35Cl) calcd for C15H11ClO2: 258.04421;
found: 258.04370.
7-Fluoro-1-hydroxy-3-methyl-9H-fluoren-9-one (7ag)
Starting with 3q (0.114 g, 0.44 mmol) and concd H2SO4 (2.3 mL),
7ag was isolated as a yellow oil; yield: 0.067 g (68%).
1H NMR (300 MHz, CDCl3): d = 2.27 (s, 3 H, CH3), 6.45 (s, 1 H,
CH), 6.74 (s, 1 H, CH), 7.01–7.09 (m, 1 H, CH), 7.21 (dd,
3J = 7.4 Hz, 4J = 3.0 Hz,
1
H, CH), 7.34 (dd, 3J = 7.5 Hz,
4J = 4.5 Hz, 1 H, CH), 8.15 (s, 1 H, OH).
13C NMR (62 MHz, CDCl3): d = 22.5 (CH3), 111.4, 114.1, 117.7,
120.4, 122.0 (CH), 129.4, 137.2, 139.6, 143.4, 149.9 (C), 157.5
(COH), 163.4 (d, 1J = 247.4 Hz, CF), 194.0 (C=O).
GC-MS (EI, 70 eV): m/z (%) = 228 (M+, 100), 199 (36), 170 (26),
151 (3), 100 (5), 85 (9).
HRMS (EI): m/z [M]+ calcd for C14H9FO2: 228.05811; found:
5-Chloro-2-ethyl-1-hydroxy-3-methyl-9H-fluoren-9-one (7ad)
Starting with 3n (80 mg, 0.27 mmol) and concd H2SO4 (3.0 mL),
7ad was isolated as a yellow solid; yield: 0.041 g (60%).
1H NMR (300 MHz, CDCl3): d = 1.04 (t, 3J = 7.8 Hz, 3 H,
CH2CH3), 2.25 (s, 3 H, CH3), 2.54 (q, 3J = 7.3 Hz, 2 H, CH2CH3),
7.02–7.08 (m, 1 H, CH), 7.22–7.26 (m, 2 H, CH), 7.38 (dd,
3J = 8.0 Hz, 4J = 0.9 Hz, 1 H, CH), 8.61 (s, 1 H, OH).
13C NMR (75 MHz, CDCl3): d = 13.1 (CH2CH3), 28.2 (CH2CH3),
20.1 (CH3), 115.2 (C), 119.2, 121.9, 129.3 (CH), 129.5, 132.5 (C),
135.5 (CH), 137.0, 139.0, 140.2, 146.4 (C), 156.0 (COH), 194.8
(C=O).
228.057995.
2-Ethyl-7-fluoro-1-hydroxy-3-methyl-9H-fluoren-9-one (7ah)
Starting with 3r (0.132 g, 0.44 mmol) and concd H2SO4 (2.3 mL),
7ah was isolated as a yellow viscous oil; yield: 0.085 g (76%).
1H NMR (300 MHz, CDCl3): d = 1.06 (t, 3J = 7.6 Hz, 3 H,
CH2CH3), 2.26 (s, 3 H, CH3), 2.56 (q, 3J = 7.4 Hz, 2 H, CH2CH3),
6.57 (s, 1 H, CH), 7.03 (ddd, 3J = 8.2 Hz, 3J = 6.3 Hz, 4J = 0.5 Hz,
1 H, CH), 7.19 (m, 1 H, CH), 7.29 (m, 1 H, CH), 8.42 (s, 1 H, OH).
13C NMR (75 MHz, CDCl3): d = 11.2 (CH2CH3), 18.3 (CH3), 28.2
(CH2CH3), 109.6 (CH), 111.9 (C), 113.1, 118.4, 119.7 (CH), 126.4,
129.7 (C), 135.0, 138.0, 144.7 (C), 154.0 (COH), 161.2 (d,
1J = 245.5 Hz, CF), 192.7 (C=O).
GC-MS (EI, 70 eV): m/z (%) = 272 (M+, 35Cl, 40), 257 (100), 229
(7), 189 (4), 165 (15).
HRMS (EI): m/z (M+, 35Cl) calcd for C16H13ClO2: 272.05986;
found: 272.05940.
GC-MS (EI, 70 eV): m/z (%) = 256 (M+, 42), 241 (100), 213 (8),
183 (12), 170 (7).
HRMS (EI): m/z [M]+ calcd for C16H13FO2: 256.08941; found:
5-Fluoro-1-hydroxy-3-methyl-9H-fluoren-9-one (7ae)
Starting with 3o (0.120 g, 0.46 mmol) and concd H2SO4 (5.7 mL),
7ae was isolated as a colorless solid; yield: 0.079 g (75%), mp 113–
118 °C.
256.08976.
3-Hydroxy-1-methyl-8,9-dihydro-4H-cyclopenta[def]phenan-
thren-4-one (11)
Starting with 9 (0.164 g, 0.6 mmol) in concd H2SO4 (7.5 mL), 11
was isolated as a brownish solid; yield: 0.056 g (40%).
1H NMR (250 MHz, CDCl3): d = 2.21 (s, 3 H, CH3), 2.83–2.89 (m,
2 H, CH2), 3.01–3.07 (m, 2 H, CH2), 6.43 (s, 1 H, CH), 6.92 (s, 1 H,
OH), 7.08–7.19 (m, 2 H, CH), 7.30–7.33 (m, 1 H, CH).
13C NMR (75 MHz, CDCl3): d = 18.6 (CH3), 22.3, 25.0 (CH2),
113.3 (C), 118.6 (CH), 121.3 (C), 122.0, 129.4 (CH), 130.3, 132.2
(C), 132.3 (CH), 140.6, 141.6, 147.2 (C), 154.2 (COH), 195.0
(C=O).
IR (neat): 3341 (s), 2923 (s), 2853 (m), 1649 (s), 1620 (s), 1585 (s),
1455 (m), 1305 (m), 1240 (s), 1199 (s), 1144 (s), 1113 cm–1 (m).
1H NMR (300 MHz, CDCl3): d = 2.36 (s, 3 H, CH3), 6.59 (s, 1 H,
CH), 7.03 (s, 1 H, CH), 7.13–7.19 (m, 1 H, CH), 7.23–7.29 (m, 1 H,
CH), 7.43 (d, 3J = 7.2 Hz, 1 H, CH), 8.30 (s, 1 H, OH).
13C NMR (75 MHz, CDCl3): d = 22.9 (CH3), 113.9 (C), 117.1,
118.8, 121.2 (CH), 128.3 (C), 129.7 (CH), 136.4, 139.7, 148.9,
155.2, 156.4, 158.5 (C), 193.3 (C=O).
MS (EI, 70 eV): m/z (%) = 228 (M+, 100), 200 (15), 199 (41), 171
(12), 170 (22).
DDQ-Mediated Dehydrogenation; General Procedure
To a soln of the substrate (1.0 equiv) in 1,4-dioxane (7 mL/mmol)
was added DDQ (2.0 equiv) under an argon atmosphere at 20 °C.
The mixture was heated under reflux for 48 h and then cooled to 20
°C and the solvent was removed in vacuo. To the residue was added
Et2O to give a precipitate, which was filtered off. The filtrate was
concentrated in vacuo and the residue was purified by column chro-
matography (silica gel, n-heptane–EtOAc, 10:1) to give the prod-
ucts.
HRMS (EI): m/z [M]+ calcd for C14H9FO2: 228.05811; found:
228.0577962.
5-Fluoro-1-hydroxy-2,3-dimethyl-9H-fluoren-9-one (7af)
Starting with 3p (111 mg, 0.4 mmol) and concd H2SO4 (4.8 mL),
7af was isolated as a yellow solid; yield: 50 mg (51%).
1H NMR (300 MHz, CDCl3): d = 2.04 (s, 3 H, CH3), 2.21 (s, 3 H,
CH3), 6.88 (s, 1 H, CH), 7.00–7.18 (m, 2 H, CH), 7.29–7.32 (m, 1
H, CH), 8.51 (s, 1 H, OH).
Synthesis 2009, No. 3, 445–463 © Thieme Stuttgart · New York

462
S. Reim et al.
PAPER
Methyl 3-Hydroxy-1-methylphenanthrene-4-carboxylate (10)
Starting with 9 (0.140 g, 0.5 mmol) and DDQ (0.308 g, 1.0 mmol)
in 1,4-dioxane (3.6 mL), 10 was isolated after column chromatog-
raphy (silica gel, n-heptane–EtOAc, 10:1) as a yellow oil; yield:
0.078 g (57%).
1H NMR (250 MHz, CDCl3): d = 2.71 (s, 3 H, CH3), 3.81 (s, 3 H,
OCH3), 7.12 (s, 1 H, CH), 7.42–7.49 (m, 1 H, CH), 7.52–7.58 (m, 1
H, CH), 7.68–7.71 (m, 1 H, CH), 7.81–7.94 (m, 3 H, CH), 9.76 (s,
1 H, OH).
1H NMR (250 MHz, CDCl3): d = 1.78 (s, 3 H, CH3), 1.97 (s, 3 H,
CH3), 2.09 (s, 3 H, CH3), 3.79 (s, 3 H, OCH3), 6.64 (s, 1 H, CHAr),
6.92–6.95 (m, 2 H, CHAr), 7.06 (d, 3J = 7.4 Hz, 1 H, CHAr), 7.19 (dd,
3J = 7.6 Hz, 4J = 1.8 Hz, 1 H, CHAr), 11.46 (br s, 1 H, OH).
13C NMR (75 MHz, CDCl3): d = 13.1, 18.7, 20.5 (CH3), 54.8
(OCH3), 110.8, 115.3, 119.6 (CHAr), 120.5, 126.1 (C), 129.1
(CHAr), 130.6 (C), 131.5 (CHAr), 134.3, 144.3 (C), 157.3 (COH),
160.3 (C), 200.1 (CO).
GC-MS (EI, 70 eV): m/z (%) = 270 (M+, 55), 255 (49), 239 (100),
224 (22), 209 (8), 162 (65), 119.1 (8), 91 (21), 77 (29), 65 (8), 51
(5), 39 (5).
13C NMR (75 MHz, CDCl3): d = 20.3 (CH3), 51.9 (OCH3), 106.7
(C), 118.8, 121.9, 124.4, 125.3 (CH), 126.2 (C), 126.7, 127.9, 128.7
(CH), 129.1, 130.5, 133.1, 142.4 (C), 159.0 (COH), 172.5 (C=O).
HRMS (EI): m/z [M]+ calcd for C17H18O3: 270.12505; found:
270.12454.
MS (EI, 70 eV): m/z (%) = 266 (M+, 40), 235 (24), 234 (100), 206
(27), 178 (61).
HRMS (EI): m/z [M]+ calcd for C17H14O3: 266.09375; found:
266.09411.
Acknowledgment
We are grateful to Dr. D. Michalik for detailed NMR studies. Finan-
cial support from the State of Pakistan (HEC scholarships for I.H.
and M.A.Y.) and from the State of Mecklenburg-Vorpommern
(scholarship for Z.A. and funds) is gratefully acknowledged.
3-Hydroxy-1-methyl-4H-cyclopenta[def]phenanthren-4-one
(12)
Starting with 11 (0.015 g, 0.06 mmol) and DDQ (0.029 g,
0.13 mmol) in 1,4-dioxane (0.5 mL), 12 was isolated after column
chromatography (silica gel, n-heptane–EtOAc, 10:1) as a yellow
solid; yield: 0.004 g (27%).
References
1H NMR (250 MHz, CDCl3): d = 2.63 (s, 3 H, CH3), 6.82 (s, 1 H,
CH), 7.49–7.61 (m, 2 H, CH), 7.68–7.74 (m, 2 H, CH), 7.85 (d,
3J = 7.9 Hz, 1 H, CH).
13C NMR (75 MHz, CDCl3): d = 18.4 (CH3), 112.5 (C), 120.3 (CH),
121.7 (C), 122.6, 122.7, 122.8 (CH), 127.7 (C), 129.0, 130.9 (CH),
133.9, 137.3, 139.4, 145.0 (C), 153.7 (COH), 194.0 (C=O).
MS (EI, 70 eV): m/z (%) = 234 (M+, 100), 233 (11), 205 (12), 178
(11).
HRMS (EI): m/z [M]+ calcd for C16H10O2: 234.06753; found:
(1) (a) Talapatra, S. K.; Bose, S.; Mallik Asok, K.; Talapatra, B.
Tetrahedron 1985, 41, 2765. (b) Sargent, M. V. J. Chem.
Soc., Perkin Trans. 1 1987, 2553. (c) Fan, C.; Wang, W.;
Wang, Y.; Qin, G.; Zhao, W. Phytochemistry 2001, 57,
1255. (d) Wu, X. Y.; Qin, G. W.; Fan, D. J.; Xu, R. S.
Phytochemistry 1994, 36, 477.
(2) Campo, M. A.; Larock, R. C. J. Org. Chem. 2002, 67, 5616;
and references cited therein.
(3) Tierney, M. T.; Grinstaff, M. W. J. Org. Chem. 2000, 65,
5355.
(4) Perry, P. J.; Read, M. A.; Davies, R. T.; Gowan, S. M.;
Reszka, A. P.; Wood, A. A.; Kelland, L. R.; Neidle, S.
J. Med. Chem. 1999, 42, 2679.
234.06716.
(3-Hydroxy-5-methylbiphenyl-2-yl)(2-methoxyphenyl)meth-
anone (16a)
Starting with 15a (0.468 g, 2.0 mmol), 14 (0.799 g, 2.2 mmol), and
TiCl4 (0.238 mL, 2.2 mmol), 16a was isolated after chromatogra-
phy (silica gel) as a colorless oil; yield: 0.190 g (30%).
(5) Gould, S. J.; Melville, C. R.; Cone, M. C.; Chen, J.; Carney,
J. R. J. Org. Chem. 1997, 62, 320.
(6) Tilly, D.; Samanta, S. S.; Faigl, F.; Mortier, J. Tetrahedron
Lett. 2002, 43, 8347.
(7) (a) Underwood, H. W.; Kochmann, E. L. J. Am. Chem. Soc.
1924, 46, 2073. (b) Lemal, D. M.; Gosselink, E. P.;
McGregor, S. D. J. Am. Chem. Soc. 1966, 88, 582.
(c) Bandyopadhyay, T. K.; Bhattacharya, A. J. Indian
J. Chem., Sect. B: Org. Chem. Incl. Med. Chem. 1980, 19,
439. (d) Kym, P. R.; Hummert, K. L.; Nilsson, A. G.; Lubin,
M.; Katzenellenbogen, J. A. J. Med. Chem. 1996, 39, 4897.
(e) Gruber, J.; Li, R. W. C.; Aguiar, L. H.; Benvenho, J. M.
C.; Adriano, R. V.; Lessmann, R.; Huemmelgen, I. A.
J. Mater. Chem. 2005, 15, 517. (f) Olah, G. A.; Mathew, T.;
Farnia, M.; Prakash, S. Synlett 1999, 1067.
(8) Danheiser, L. R.; Gould, E. A.; Pradilla, F. R.; Helgason, L.
A. J. Org. Chem. 1994, 59, 5514.
(9) (a) Murahashi, S.-I.; Komiya, N.; Oda, Y.; Kuwabara, T.;
Naota, T. J. Org. Chem. 2000, 65, 9186. (b) Lippert, E.;
Walter, H. Angew. Chem. 1959, 71, 429.
IR (neat): 3427 (w), 3054 (w), 2922 (m), 1623 (s), 1490 (s), 1432
(m), 1279 (s), 1207 (s), 1162 (m), 1023 (m), 917 (s), 754 (s), 700
(m), 639 cm–1 (w).
1H NMR (250 MHz, CDCl3): d = 2.26 (s, 3 H, CH3), 3.52 (s, 3 H,
OCH3), 6.05 (s, 1 H, CHAr), 6.28 (d, 3J = 7.3 Hz, 1 H, CHAr), 6.46–
6.49 (m, 3 H, CHAr), 6.78 (s, 1 H, CHAr), 6.80–6.89 (m, 4 H, CHAr),
7.70–7.72 (d, 3J = 7.5 Hz, 1 H, CHAr), 11.10 (br s, 1 H, OH).
13C NMR (75 MHz, CDCl3): d = 22.2 (CH3), 55.3 (OCH3), 110.9,
117.2, 119.4, 123.9, 127.2, 127.4, 127.6, 129.0, 129.6, 130.0
(CHAr), 130.9 (C), 132.3 (CHAr), 132.6, 141.4, 145.7, 146.1 (C),
156.6 (COH), 162.0 (C), 194.1 (CO).
GC-MS (EI, 70 eV): m/z (%) = 318 (M+, 12), 317 (12), 303 (22),
287 (100), 210 (5), 182 (4), 165 (6), 135 (8), 77 (9).
Anal. Calcd for C21H18O3: C 78.93, H 5.33; found: C 78.97, H 5.35.
(10) Fu, J.-m.; Zhao, B.-p.; Sharp, M. J.; Snieckus, V. J. Org.
Chem. 1991, 56, 1683.
(11) Yu, Z.; Velasco, D. Tetrahedron Lett. 1999, 40, 3229.
(12) Ciske, F. L.; Jones, W. D. Jr. Synthesis 1998, 1195.
(13) Schmidt, J. M.; Tremblay, G. B.; Page, M.; Mercure, J.;
Feher, M.; Dunn-Dufault, R.; Peter, M. G.; Redden, P. R.
J. Med. Chem. 2003, 46, 1289.
(6-Hydroxy-2,3,4-trimethylphenyl)(2-methoxyphenyl)meth-
anone (16b)
Starting with 15b (0.371 g, 2.0 mmol), 14 (0.799 g, 2.2 mmol), and
TiCl4 (0.238 mL, 2.2 mmol), 16b was isolated after chromatogra-
phy (silica gel) as a colorless solidifying oil; yield: 0.205 g (38%);
mp 127–130 °C.
IR (neat): 3333 (m), 1663 (s), 1596 (m), 1486 (m), 1442 (s), 1317
(m), 1244 (s), 1075 (w), 908 (w), 855 (w), 759 cm–1 (m).
Synthesis 2009, No. 3, 445–463 © Thieme Stuttgart · New York

PAPER
Synthesis of Biaryls, Fluorenones, Cyclopenta[def]phenanthren-4-ones, and Benzophenones
463
(14) (a) Chan, T.-H.; Brownbridge, P. J. Am. Chem. Soc. 1980,
102, 3534. (b) Brownbridge, P.; Chan, T.-H.; Brook, M. A.;
Kang, G. J. Can. J. Chem. 1983, 61, 688.
chlorinated and fluorinated arenes, we have recently
reported the synthesis of fluorenones: (a) Hussain, I.;
Yawer, M. A.; Lau, M.; Pundt, T.; Fischer, C.; Reinke, H.;
Görls, H.; Langer, P. Eur. J. Org. Chem. 2008, 503.
(b) Yawer, M. A.; Hussain, I.; Reim, S.; Ahmed, Z.; Ullah,
E.; Iqbal, I.; Fischer, C.; Reinke, H.; Görls, H.; Langer, P.
Tetrahedron 2007, 63, 12562.
(15) For a review of 1,3-bis(silyl enol ethers), see: Langer, P.
Synthesis 2002, 441.
(16) For a review of [3+3] cyclizations, see: Feist, H.; Langer, P.
Synthesis 2007, 327.
(17) Reim, S.; Lau, M.; Langer, P. Tetrahedron Lett. 2006, 47,
6903.
(18) An isolated example of this method has been previously
reported by Chan: see ref. 14a. During the synthesis of
(19) CCDC 626089 and CCDC 698467 contain the
crystallographic details of 7b and 7ab. These data are
available free of charge at www.ccdc.cam.ac.uk/conts/
retrieving.html or can be ordered from the following
address: Cambridge Crystallographic Data Centre, 12 Union
Road, Cambridge CB2 1EZ, UK; Fax: +44(1223)336033, or
deposit@ccdc.cam.ac.uk.
Synthesis 2009, No. 3, 445–463 © Thieme Stuttgart · New York