Manganese(III) acetate-mediated cyclization of diarylmethylenecyclopropa[ b ]naphthalenes: A method for the synthesis of 1,2-benzanthracene derivatives

Article abstract of DOI:10.1021/jo2015906

The manganese(III) acetate-mediated free radical cyclization of diarylmethylenecyclopropa[b]naphthalenes with nucleophiles such as carboxylic acid and sulfonic acid provides an efficient method for the synthesis of 1,2-benzanthracenes in moderate to good yields under mild conditions. In addition, after several steps of simple and routine operations, the obtained 1,2-benzanthracenes bearing an acetoxy group could be easily converted to structurally more sophisticated 1,2-benzanthracene derivatives, which are not easily accessible yet potentially useful candidates for materials science.

Full text of DOI:10.1021/jo2015906

Article
pubs.acs.org/joc
Manganese(III) Acetate-Mediated Cyclization of
Diarylmethylenecyclopropa[b]naphthalenes: A Method for the
Synthesis of 1,2-Benzanthracene Derivatives
Jian Cao,† Maozhong Miao,† Wanli Chen,‡ Luling Wu,*,† and Xian Huang†,§,⊥
†Department of Chemistry, Zhejiang University, Xi-xi Campus, Hangzhou 310028, People’s Republic of China
‡Zhejiang University of Technology, Chaowang Road, Hangzhou, People’s Republic of China
§State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences,
Shanghai 200032, People’s Republic of China
S
* Supporting Information
ABSTRACT: The manganese(III) acetate-mediated free radical
cyclization of diarylmethylenecyclopropa[b]naphthalenes with
nucleophiles such as carboxylic acid and sulfonic acid provides
an efficient method for the synthesis of 1,2-benzanthracenes in
moderate to good yields under mild conditions. In addition, after
several steps of simple and routine operations, the obtained 1,2-benzanthracenes bearing an acetoxy group could be easily
converted to structurally more sophisticated 1,2-benzanthracene derivatives, which are not easily accessible yet potentially useful
candidates for materials science.
prepared from naphthalene according to the known procedure
(Scheme 1).45 Due to their unusual structure, which contains a
triafulvene, a [3]radialene, and a cycloproparene unit,
diarylmethylenecyclopropa[b]naphthalenes 1 are of considerable
importance for physical and theoretical study.46−49 Recently, they
also have attracted much attention from synthetic viewpoints and
have been used as building blocks for the synthesis of otherwise
inaccessible compounds. In this regard, we have reported a highly
regioselective Pd(0)-catalyzed [3 + 2] cycloaddition reaction of
diarylmethylenecyclopropa[b]naphthalenes with alkenes, alkynes,
or arynes to produce 1(3)-alkylidene-2,3-dihydro-1H-cyclopenta-
[b]naphthalene, 1-alkylidene-1H-cyclopenta[b]naphthalene, and
11-diarylmethylene-11H-benzo[b]fluorine derivatives.43,44 As a
continuing exploration on the synthetic utility of these interesting
compounds, in this paper, we wish to disclose a manganese(III)
acetate-mediated radical cyclization reaction of 1 with nucleophiles
such as carboxylic acid, sulfonic acid, and hydrazoic acid, affording
an efficient synthesis of 1,2-benzanthracenes 2. Meanwhile, we
also demonstrate that compounds 2 could be easily converted to
1,2-benzanthracene derivatives with more advanced structures
after several simple and routine operations (Scheme 2).
INTRODUCTION
■
The chemistry of polycyclic aromatic hydrocarbons (PAHs) has
become a field of increasing interest during the past decades,
particularly in materials science because of their unique electrical
and optical properties.1−5 The charge transport properties exhibited
by some PAHs, for example, make them potential candidates for
organic optoelectronic devices such as light-emitting diodes, field-
effect transistors, and photovoltaics.6−12 PAHs with 1,2-benzan-
thracene skeletons are also of considerable importance due to their
applications as carcinogenic activity compounds in medical
chemistry as well as valuable synthetic intermediates in organic
synthesis.13 Therefore, much attention has been paid to the
synthesis of 1,2-benzanthracene derivatives. Many known methods
have provided reliable routes; however, most of them require
multiple steps or harsh conditions.14−21 Thus, it remains highly
desired to develop facile and efficient protocols for their synthesis.
On the other hand, the Mn(III)-mediated radical cyclization has
become a valuable method for the synthesis of cyclic compounds
during the past 30 years.22−25 The previous investigations have
shown that Mn(OAc)3·2H2O is a useful reagent for oxidative
single-electron transfer processes leading to a large number of
novel carbon−carbon and carbon−heteroatom bond-forming
reactions. Numerous chemo-, regio-, and stereoselective synthetic
methods have been developed in both inter- and intramolecular
manners, and their applicability to the construction of natural and
biologically active molecules has been demonstrated, as well.26−37
We have been engaged in the synthetic application of
methylenecyclopropanes (MCPs) for years, and a variety of
useful reactions for the synthesis of various compounds were
developed based on these structurally interesting molecules.38−44
Recently, we were interested in the chemistry of its analogues,
diarylmethylenecyclopropa[b]naphthalenes 1, which can be
RESULTS AND DISCUSSION
■
As an initial examination on the reaction of 1-(diphenyl-
methylene)-1H-cyclopropa[b]naphthalene 1a with 3.0 equiv of
manganese(III) acetate dihydrate (Mn(OAc)3·2H2O) in HOAc
at 25 °C, fortunately, we found that 5-phenyl-1,2-benzan-
thracene-6-yl acetate 2a was produced in 80% yield after 24 h
(Table 1, entry 1). The structure of 2a was unambiguously
Received: July 30, 2011
Published: October 12, 2011
© 2011 American Chemical Society
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Scheme 1
Scheme 2
Table 1. Optimization on the Reaction of 1-(Diphenylmethylene)-1H-cyclopropa[b]naphthalene 1a with Oxidants under
a
Various Conditions
b
entry
Mn(OAc)3·2H2O (equiv)
solvent
temp (°C)
time (h)
yield of 2a (%)
1
2
3
4
5
6
7
8
9
3.0
3.0
3.0
2.4
2.4
2.4
2.4
HOAc
HOAc
HOAc
HOAc
THF
25
40
60
40
60
60
60
40
24
4
80
93
86
93
0.5
4
c
24
24
24
24
0.5
trace
c
CHCl3
CH3OH
HOAc
HOAc
trace
d
20
e
2.4
trace
trace
f
2.4
40
a
b
c
d
The reactions were conducted with 0.2 mmol of 1a in 2 mL of solvent. Isolated yield. 90% of 1a was recovered. 70% of 1a was recovered.
e
f
Cu(OAc)2 was used instead of Mn(OAc)3·2H2O. (NH4)2Ce(NO3)6 was used instead of Mn(OAc)3·2H2O.
confirmed by X-ray diffraction analysis.50 Several reaction
reaction. As shown in Table 2, diarylmethylenecyclopropa[b]-
naphthalenes 1 with electron-withdrawing aryl groups such as
p-FC6H4, p-Cl C6H4, and p-Br C6H4 all gave the corresponding
products in good yields (Table 2, entries 2−4). Substrate 1e
bearing electron-donating aryl groups (Ar = 3,5-dimethoxyphenyl)
also reacted smoothly to produce the expected product 2e in 84%
yield (Table 2, entry 5). Treatment of diarylmethylenecyclopropa-
[b]naphthalene bearing p-tolyl groups (1f) with Mn(OAc)3·2H2O
efficiently gave a 90% yield of desired compound 2f.
Comparatively, the reaction of diarylmethylenecyclopropa[b]-
naphthalene with a m-tolyl group (1g) gave the corresponding
compounds 2g and 2g′ as a 1:1 mixture of inseparable isomers in
an 85% overall yield (Table 2, entries 6 vs 7). In addition, an
interesting result was observed when we employed the substrate 1h
which bears a phenyl and methyl group; the desired compound 2h
was produced in 35% yield together with 1-(naphthalen-2-yl)-2-
phenylprop-2-en-1-one (2h′) in 33% yield (Scheme 3).
We also examined the reaction of diarylmethylenecyclopropa-
[b]naphthalenes 1 with other carboxylic acids. The corresponding
1,2-benzanthracenes were also successfully obtained. For example,
the reaction of 1a with Mn(OAc)3·2H2O in hexanoic acid
produced 5-phenyl-1,2-benzanthracene-6-yl hexanoate (2i) in 86%
yield (eq 1, Scheme 4), and treatment of 1a with excessive benzoic
acid using THF as solvent also selectively led to the formation of
parameters were subsequently investigated to optimize the
reaction conditions. The results are summarized in Table 1. It
was found that the reaction proceeded much more efficiently at
40 °C, therefore producing 2a in 93% yield within 4 h (Table 1,
entry 2). However, the yield dropped to 86% at 60 °C,
although the reaction could complete within 0.5 h (Table 1,
entry 3). The amount of Mn(OAc)3·2H2O could be reduced
from 3.0 equiv to 2.4 equiv with a similar yield of 2a (Table 1,
entry 4). The reaction conducted in other solvents such as
THF, CHCl3, or CH3OH gave 2a in very low yields (entries
5−7). For example, in THF and CHCl3, only trace amount of
2a was obtained, and in CH3OH, the yield of 2a was limited to
20%. In addition, other oxidants such as ammonium cerium-
(IV) nitrate (CAN) and copper(II) acetate (Cu(OAc)2)
were also examined, but only a trace amount of 2a was formed
(Table 1, entries 8 and 9). Overall, the optimized reaction
condition is defined as follows: 1.0 equiv of 1 reacted with
2.4 equiv of Mn(OAc)3·2H2O in HOAc at 40 °C(Table 1,
entry 4).
With the optimized reaction conditions in hand, a variety of
diarylmethylenecyclopropa[b]naphthalenes 1, which bear substi-
tuted phenyl rings as the Ar group, were synthesized and treated
with Mn(OAc)3·2H2O and HOAc to examine the scope of the
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a
Table 2. Reactions of Diarylmethylenecyclopropa[b]naphthalenes 1 with Mn(OAc)3·2H2O To Produce 5-Aryltetraphen-6-yl Acetate 2
b
entry
Ar (1)
C6H5 (1a)
R (2)
2-H (2a)
time (h)
yield (%)
1
2
3
4
5
6
7
4
8
93
85
82
86
84
90
4-FC6H4 (1b)
2-F (2b)
4-ClC6H4 (1c)
4-BrC6H4 (1d)
3,5-MeOC6H4 (1e)
4-MeC6H4 (1f)
3-MeC6H4 (1g)
2-Cl (2c)
20
24
12
2
2-Br (2d)
1,3-MeO (2e)
2-Me (2f)
c
3-Me (2g)/1-Me (2g′)
4
85 (1:1)
a
b
c
The reactions were conducted with 0.2 mmol of 1 and 0.48 mmol of Mn(OAc)3·2H2O in 2 mL of HOAc at 40 °C. Isolated yield. The ratio of
1
products was determined by H NMR spectral analysis
Scheme 3. Reactions of 1h with Mn(OAc)3·2H2O
Scheme 4. Reactions of 1-(Diphenylmethylene)-1H-
cyclopropa[b]naphthalene 1a with Nucleophiles and
Mn(OAc)3·2H2O and the Synthetic Utilities of 2l
benzanthracene (2k) and 6-azido-5-phenyl-1,2-benzanthracene
(2l), albeit in a relatively low yield. Herein, it should also be
mentioned that 6-azido-5-phenyl-1,2-benzanthracene (2l) may be
quite useful for the synthesis of polycyclic aromatic hydrocarbons
with heterocycles due to the versatile transformation of the azido
group.51−53 As exemplified in eq 4, by direct heating a solution of
2l in toluene and HOAc for 5 h, a new polycyclic compound, 11H-
benzo[c]naphtho[2,3-a]carbazole (3a), could be obtained in 91%
yield via an unprecedented oxidative cyclization reaction.
On the basis of the above results and the known chemistry of the
manganese(III) acetate-mediated reaction,22−25 the current reaction
can be rationalized as follows (Scheme 5). The single-electron
oxidation of 1 by Mn(OAc)3 may furnish radical cation A,54,55
which subsequently accepts the nucleophilic attack of Nu−, with
high regioselectivity to give the radical intermediate B. Then the
ring opening occurs with the highly strained three-membered ring
of intermediate B giving radical intermediate C or D.41 The
intramolecular cyclization of intermediate C, in which the phenyl
group and the free radical is on the same side, produces 2 with the
loss of a proton and oxidation by another molecule of Mn(OAc)3
(Scheme 5, path a); when R is a methyl group and it is on the same
side with the free radical (Scheme 5, path b), the 1,5-H shift of
radical intermediate D produces the allylic radical intermediate E.
In the presence of another molecule of Mn(OAc)3, E can be
further converted to the allylic cation F. Then the migration of the
CC of F gives the intermediate G, which can be attacked by
OH− to furnish H. At last, 2h′ is obtained by the elimination of a
molecule of HOAc from H.
Transition-metal-catalyzed coupling reaction of aryl esters
with organometallic reagents is a very useful method to
synthesize aryl−aryl products with extended π system.56−58
Considering the readily available 1,2-benzanthracenes 2 bearing
ester functionality with the current protocol, our further
experiments applying the nickel-catalyzed Suzuki coupling
reaction of 2a with arylboronic acids demonstrated that a
5-phenyl-1,2-benzanthracene-6-yl benzoate (2j) in 60% yield (eq 2,
Scheme 4). Interestingly, when diarylmethylenecyclopropa[b]-
naphthalene 1a was treated with PhSO2H or HN3, which were
generated in situ from a mixture of PhSO2Na or NaN3 with HOAc,
we also observed the formation of 5-phenyl-6-(phenylsulfonyl)-1,2-
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variety of 1,2-benzanthracene derivatives could be successfully
obtained. As shown in Table 3, arylboronic acids both with
electron-donating and electron-withdrawing substituents
coupled smoothly with 2a to give the corresponding products
in good yields. Nevertheless, alkylboronic acids unfortunately
cannot be applied in these reactions. Thus, we developed an
alternative route by using 5-aryltetraphen-6-yl triflates 7 as the
cross-coupling precursors. Aryl triflates could be easily
generated from arylols with Tf2O. They have higher reactivity
than their acetate counterparts and consequently wider
application in the transition-metal-catalyzed coupling reactions.
As shown in Scheme 6, treatment of 2a with NaOH in MeOH
followed by esterification with triflic anhydride afforded 5-
phenyltetraphen-6-yl triflate (7a) in 82% yield (two steps). In
the presence of 5 mol % of Pd(PPh3)4 and 3.0 equiv of K3PO4,
7a successfully coupled with (E)-styrylboronic acid and
butylboronic acid to give the coupled products 5f and 5g in
73 and 74% yields, respectively. In addition, the reaction of 7a
with terminal alkynes catalyzed by a combination of 5 mol % of
Scheme 5. Proposed Mechanism
59
Pd(PPh3)4 and 5 mol % of AuClPPh3 also proceeded
smoothly to afford 5h and 5i in good yields.
Table 3. Suzuki Coupling Reaction of 5-Phenyl-1,2-
a
benzanthracene-6-yl Acetate 2a with Arylboronic Acids
CONCLUSIONS
■
In conclusion, we have disclosed a manganese(III) acetate-
mediated oxidative annulation of diarylmethylenecyclopropa[b]-
naphthalenes with nucleophiles such as carboxylic acid and sulfonic
acid under mild conditions, providing an efficient method for
the preparation of 1,2-benzanthracenes. We also demonstrated that
the obtained 1,2-benzanthracenes 2 could be easily converted to
1,2-benzanthracene derivatives with more advanced structures with
several simple and routine operations. Further studies in this area
are being conducted in our laboratory.
b
entry
Ar (4)
C6H5 (4a)
product 5
yield (%)
1
2
3
4
5
5a
5b
5c
5d
5e
66
75
74
66
61
4-FC6H4 (4b)
4-MeC6H4 (4c)
4-MeOC6H4 (4d)
3-MeOC6H4 (4e)
EXPERIMENTAL SECTION
■
Materials. 1,4-Dioxane and THF were distilled from Na/
benzophenone immediately prior to use. Petroleum ether refers to
the fraction with the boiling point in the range of 60−90 °C. DMF was
a
The reactions were conducted with 0.1 mmol of 2a, 0.3 mmol of
boroxine 4, 0.005 mmol of Ni(PCy3)2Cl2, and 0.6 mmol of K3PO4 in
b
1
distilled from MgSO4. All H NMR (400 MHz) and 13C NMR (100
1 mL of 1,4-dioxane at 110 °C for 20 h. Isolated yield.
Scheme 6. Synthetic Utilities of 2a
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MHz) spectra were measured in CDCl3 with TMS as the internal
standard unless noted otherwise. Chemical shifts are expressed in parts
per million, and J values are given in hertz. The other commercially
available chemicals were purchased and used without further
purification unless noted otherwise.
(M+(79,81Br), 7.95), 518 (M+(79,79Br), 4.05), 49(100); IR (neat) 2982,
1761, 1592, 1491, 1369, 1194, 1059, 1012, 939, 875, 823, 7465, 705
cm−1; HRMS calcd for C26H16O279Br2 (M+) 517.9517, found
517.9513.
5-(3,5-Dimethoxyphenyl)-1,3-dimethoxy-1,2-benzanthracene-6-
yl Acetate (2e). The reaction of Mn(OAc)3·2H2O (85 mg, 0.48
mmol) and 1e (85 mg, 0.2 mmol) in HOAc (2 mL) afforded 2e (81
mg, 84%) as a white solid (eluent, petroleum ether/AcOEt = 10:1) mp
160−162 °C (petroleum ether); 1H NMR (400 MHz, CDCl3, 25 °C)
δ = 10.14 (s, 1H), 8.30 (s, 1H), 8.12−8.10 (m, 1H), 8.00−7.98 (m,
1H), 7.53−7.49 (m, 2H), 6.80 (s, 1H), 6.68 (s, 1H), 6.58−6.56 (m,
3H), 4.14 (s, 3H), 3.80 (s, 6H), 3.72, 3H), 2.19 (s, 3H) ppm; 13C
NMR (100 MHz, CDCl3 , 25 °C) δ = 169.4, 160.6, 160.1, 158.3,
143.3, 138.2, 135.1, 132.4, 130.5, 129.0, 128.8, 128.7, 127.7, 127.4,
125.7, 125.7, 124.8, 120.1, 113.9, 107.8, 102.4, 100.2, 98.7, 55.9, 55.4,
55.2, 20.7 ppm; MS m/z (%) = 483 (M + 1+, 16.14), 441(100); IR
(neat) 2969, 1759, 1603, 1456, 1422, 1373, 1319, 1294, 1200, 1157,
1067, 1018, 837 cm−1; HRMS calcd for C30H26O6 (M+) 482.1729,
found 482.1744.
General Experimental Procedures. Synthesis of 5-Phenyl-
1,2-benzanthracene-6-yl Acetate (2a). Representative General
Procedure for the Preparation of 1,2-Benzanthracene-6-yl Acetates
2a−2l. A rubber-capped Schlenk vessel containing Mn(OAc)3·2H2O
(85 mg, 0.48 mmol) and 1-(diphenylmethylene)-1H-cyclopropa[b]-
naphthalene (1a) (61 mg, 0.2 mmol) was degassed and backfilled with
nitrogen three times, then HOAc (2 mL) was added to the Schlenk
vessel. The resulting mixture was then allowed to stir at 40 °C. After 4 h,
the reaction was complete as monitored by TLC. The reaction solution
was diluted with ether (20 mL) and washed with a saturated aqueous
NaHCO3 solution (20 mL × 3). The combined oganic layer was dried
over anhydrous MgSO4. The solvent was removed under reduced
pressure, and the residue was purified by a flash column
chromatography (petroleum ether/CH2Cl2 = 10:1) to afford 2a (67
1
mg, 93%) as a white solid: mp 157−158 °C (petroleum ether); H
2-Methyl-5-p-tolyl-1,2-benzanthracene-6-yl acetate (2f). The
reaction of Mn(OAc)3·2H2O (85 mg, 0.48 mmol) and 1f (66 mg,
0.2 mmol) in HOAc (2 mL) afforded 2f (70 mg, 90%) as a white solid
(eluent, petroleum ether/CH2Cl2 = 10:1) mp 198−199 °C
NMR (400 MHz, CDCl3, 25 °C) δ = 9.19 (s, 1H), 8.83 (d, J = 8.4 Hz,
1H), 8.33 (s, 1H), 8.11−8.07 (m,1H), 8.03−87.99 (m, 1H), 7.64 (m,
1H), 7.56−7.40 (m, 9H), 2.11 (s, 3H) ppm; 13C NMR (100 MHz,
CDCl3, 25 °C) δ = 169.4, 142.4, 135.6, 132.1, 132.0, 130.2, 129.5, 129.2,
129.1, 128.4, 128.3, 128.1, 127.7, 127.3, 127.2, 126.6 126.2, 125.2, 122.9,
122.0, 121.0, 20.5 ppm; MS m/z (%) = 362 (M+, 14.16), 320(100); IR
(neat) 3054, 1761, 1497, 1438, 1367, 1195, 1059, 1008, 873, 757, 734,
703 cm−1; HRMS calcd for C26H18O2 (M+) 362.1307, found 362.1315.
The following compounds were prepared according to this
procedure.
1
(petroleum ether); H NMR (400 MHz, CDCl3, 25 °C) δ = 9.17
(s, 1H), 8.63 (s, 1H), 8.30 (s, 1H), 8.11−8.08 (m, 1H), 8.01−7.98 (m,
1H), 7.55−7.49 (m, 2H), 7.43 (d, J = 8.4 Hz, 1H), 7.30−7.27 (m,
5H), 2.60 (s, 3H), 2.45 (s, 3H), 2.14 (s, 3H) ppm; 13C NMR (100
MHz, CDCl3, 25 °C) δ = 169.5, 141.6, 137.2, 136.3, 132.7, 132.0,
132.0, 130.0, 129.9, 129.5, 129.1, 119.1, 129.0, 128.6, 128.3, 128.0,
127.3, 126.0, 126.0, 125.4, 123.0, 121.9, 120.8, 21.8, 21.3, 20.6 ppm;
MS m/z (%) = 390 (M+, 14.47), 348 (100); IR (neat) 2982, 1760,
2-Fluoro-5-(4-fluorophenyl)-1,2-benzanthracene-6-yl acetate
(2b). The reaction of Mn(OAc)3·2H2O (85 mg, 0.48 mmol) and
1b (68 mg, 0.2 mmol) in HOAc (2 mL) afforded 2b (68 mg, 85%) as
a white solid (eluent, petroleum ether/CH2Cl2 = 10:1) mp 216−217
1621, 1511, 1369, 1302, 1203, 1124, 1061, 952, 874, 822, 744 cm−1
HRMS calcd for C28H22O2 (M+) 390.1620, found 390.1615.
;
3-Methyl-5-m-toly-1,2-benzanthracene-6-yl Acetate (2g) and 1-
Methyl-5-m-tolyl-1,2-benzanthracene-6-yl Acetate (2g′). The reac-
tion of Mn(OAc)3·2H2O (85 mg, 0.48 mmol) and 1g (66 mg, 0.2
mmol) in HOAc (2 mL) afforded a mixture of 2g and 2g′ (1:1) (66
mg, 85%) as a white solid (eluent, petroleum ether/CH2Cl2 = 10:1):
1H NMR (400 MHz, CDCl3, 25 °C) δ = 9.33 (s, 1H), 9.13 (s, 1H),
8.71 (d, J = 8.4 Hz, 1H), 8.34 (s, 1H), 8.30 (s, 1H), 8.09−8.06 (m,
2H), 8.02−7.99 (m, 2H), 7.56−7.18 (m, 17H), 3.223 (s, 3H),2.44−
2.38 (m, 9H), 2.13−2.10 (m, 6H) pm; 13C NMR (100 MHz, CDCl3,
25 °C) δ = 169.5, 142.4, 142.1, 137.8, 137.1, 136.2, 135.7, 135.6, 135.5,
132.1, 131.8, 131.4, 131.3, 131.1, 130.7, 130.7, 130.2, 129.6, 129.4,
129.3, 129.2, 128.7, 128.4, 128.3, 128,2, 128.1, 128.1, 127.7, 127.7
127.2, 126.3, 126.2, 126.1, 126.1, 126.0, 125.9, 125.0, 122.8, 121.6,
120.9, 120.2, 27.4, 21.6, 21.5, 21.5, 20.5 ppm; MS m/z (%) = 390 (M+,
14.16), 348(100); IR (neat) 3053, 1759, 1603, 1499, 1439, 1305,
1265, 1195, 1601, 874, 735, 703 cm−1; HRMS calcd for C28H22O2
(M+) 390.1620, found 390.1617.
1
°C (petroleum ether); H NMR (400 MHz, CDCl3, 25 °C) δ = 8.99
(s, 1H), 8.42−8.39 (m, 1H), 8.28 (s, 1H), 8.07−7.97 (m, 2H), 7.55−
7.52 (m, 2H), 7.44−7.34 (m, 3H), 7.24−7.17 (m, 3H), 2.16 (s, 3H)
ppm; 13C NMR (100 MHz, CDCl3, 25 °C) δ = 169.2, 162.4 (d, J =
245.4 Hz), 161.7 (d, J = 254.4 Hz), 142.0 (d, J = 3.1 Hz), 132.3, 132.0,
131.9, 131.9, 131.3 (d, J = 8.1 Hz), 131.2 (d, J = 3.0 Hz), 129.1 (d. J =
8.8 Hz), 128.3, 128.0, 127.6, 126.6, 126.4, 125.1, 122.4, 121.1, 115.6,
115.5, 115.3, 108.7(d, J = 22.6 Hz), 20.4 ppm; MS m/z (%) = 398
(M+, 14.40), 356(100); IR (neat) 2923, 1760, 1710, 1608, 1511, 1433,
1368, 1266, 1187, 1108, 1057, 1017, 838 cm−1; HRMS calcd for
C26H16O2F2 (M+) 398.1118, found 398.1115.
2-Chloro-5-(4-chlorophenyl)-1,2-benzanthracene-6-yl Acetate
(2c). The reaction of Mn(OAc)3·2H2O (85 mg, 0.48 mmol) and 1c
(75 mg, 0.2 mmol) in HOAc (2 mL) afforded 2c (71 mg, 82%) as a
white solid (eluent, petroleum ether/CH2Cl2 = 10:1) mp 243−245 °C
(petroleum ether);1H NMR (400 MHz, CDCl3, 25 °C) δ = 9.13 (s,
1H), 8.80 (s, 1H), 8.33 (s, 1H), 8.15−8.10 (m, 1H), 8.05−8.03 (m,
1H), 7.60−7.57 (m, 2H), 7.53−7.47 (m, 2H), 7.46−7.24 (m, 4H),
2.19(s, 3H) ppm; 13C NMR (100 MHz, CDCl3 , 25 °C) δ = 169.2,
142.7, 134.1, 133.6, 133.1, 132.3, 132.2, 131.6, 130.9, 130.1, 128.8,
128.5, 128.1, 127.6, 127.4, 126.7, 126.6, 125.1, 122.8, 122.4, 121.3, 20.6
ppm; MS m/z (%) = 434 ([M+(37,37Cl)], 1.99), 432 (M+(35,37Cl),
10.16), 430 (M+(35,35Cl),14.25), 388 (100); IR (neat) 3053, 1758, 1596,
1540, 1494, 1435, 1372, 1320, 1197, 1123, 1093, 874, 824, 777, 739
cm−1; HRMS calcd for C26H16O235Cl2(M+) 430.0527, found 430.0531.
2-Bromo-5-(4-bromophenyl)-1,2-benzanthracene-6-yl Acetate
(2d). The reaction of Mn(OAc)3·2H2O (85 mg, 0.48 mmol) and
1d (92 mg, 0.2 mmol) in HOAc (2 mL) afforded 2d (89 mg, 86%) as
a white solid (eluent, petroleum ether/CH2Cl2 = 10:1) mp 270−272
5-Methyl-1,2-benzanthracene-6-yl Acetate (2h) and 1-(Naph-
thalen-2-yl)-2-phenylprop-2-en-1-one (2h′). The reaction of Mn-
(OAc)3·2H2O (85 mg, 0.48 mmol) and 1h (48 mg, 0.2 mmol) in
HOAc (2 mL) afforded 2h (21 mg, 35%) and 2h′ (17 mg, 33%) both
as white solid (eluent, petroleum ether/CH2Cl2 = 10:1). 2h: mp 135−
1
137 °C (petroleum ether); H NMR (400 MHz, CDCl3, 25 °C) δ =
9.17 (s, 1H), 8.87−8.83 (m, 1H), 8.27 (s, 1H), 8.13−8.10 (m, 1H),
8.05−8.02 (m, 2H), 7.69−7.65 (m, 2H), 7.56−7.53 (m, 2H), 2.61 (s,
3H), 2.54 (s, 3H) ppm; 13C NMR (100 MHz, CDCl3, 25 °C) δ =
169.1, 142.6, 132.0, 132.0, 131.8, 129.4, 128.9, 128.4, 128.1, 127.4,
126.5, 126.1, 125.9, 125.5, 125.0, 123.2, 122.8, 121.9, 120.2, 20.8, 12.7
ppm; MS m/z (%) = 300 (M+, 38.70), 258 (100); IR (neat) 2987,
2901, 1759, 1630, 1503, 1406, 1394, 1201, 1142, 1066, 1056, 872, 753
cm−1; HRMS calcd for C21H16O2 (M+) 300.1150, found 300.1151.
2h′: mp 80−82 °C (petroleum ether); 1H NMR (400 MHz, CDCl3,
25 °C) δ = 8.41 (s, 1H), 8.04−8.00 (m, 1H), 7.91−7.85 (m, 3H),
7.62−7.46 (m, 4H), 7.37−7.31 (m, 3H), 6.13 (s, 1H), 5.70 (s, 1H)
ppm; 13C NMR (100 MHz, CDCl3, 25 °C) δ = 197.6, 148.3, 137.1,
135.6, 134.4, 132.4, 132.3, 129.6, 128.7, 128.6, 128.5, 128.4, 127.8,
127.0, 126.7, 125.1, 120.6 ppm; MS m/z (%) = 258 (M+, 34.21), 155
1
°C (petroleum ether); H NMR (400 MHz, CDCl3, 25 °C) δ = 9.07
(s, 1H), 8.92 (s, 1H), 8.30 (s, 1H), 8.10 (d, J = 7.6 Hz, 1H), 8.02 (d,
J = 8.0 Hz, 1H), 7.68−7.64 (m, 2H), 7.58−7.54 (m, 3H), 7.30−7.25
(m, 3H), 2.19(s, 3H) ppm; 13C NMR (100 MHz, CDCl3 , 25 °C) δ =
169.1, 142.7, 134.0, 132.3, 132.2, 131.9, 131.7, 131.1, 130.3, 128.5,
128.4, 128.1, 128.0, 127.4, 126.7, 126.6, 125.9, 124.9, 122.4, 122.2,
121.3, 121.3, 20.5 ppm; MS m/z (%) = 522 (M+(81,81Br), 4.20), 520
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(100); IR (neat) 2981, 2901, 1661, 1626, 1597, 1495, 1465, 1403,
1324, 1249, 1179, 1069, 830, 793,700 cm−1; HRMS calcd for C19H14O
(M+) 258.1045, found 258.1049.
reduced pressure, and the residue was purified by a flash column
chromatography (petroleum ether/AcOEt = 5:1) to afford 3a (58 mg,
1
91%) as a white solid: mp 250−252 °C (petroleum ether); H NMR
5-Phenyl-1,2-benzanthracene-6-yl Hexanoate (2i). The reaction
of Mn(OAc)3·2H2O (85 mg, 0.48 mmol) and 1a (61 mg, 0.2 mmol)
in hexanoic acid (2 mL) afforded 2a(4 mg, 5%) and 2i (72 mg, 86%)
as a white solid (eluent, petroleum ether/CH2Cl2 = 10:1): mp 98−
99 °C (petroleum ether); 1H NMR (400 MHz, CDCl3, 25 °C)
δ = 9.23 (s, 1H), 8.87 (d, J = 8.0 Hz, 1H), 8.33 (s, 1H), 8.15−8.11
(m, 1H), 8.04−8.00 (m, 1H), 7.68−7.63 (m, 1H), 7.57−7.40 (m, 9H),
2.42(t, J = 8.0 Hz, 2H), 1.51−1.45 (m, 2H),1.31−1.18 (m, 4H),
0.90(t, J = 7.2 Hz, 3H) ppm; 13C NMR (100 MHz, CDCl3, 25 °C) δ =
172.1, 142.3, 135.7, 132.2, 132.1, 132.0, 130.3, 129.5, 129.3, 129.2,
128.4, 128.3, 128.1, 127.7, 127.3, 127.2, 126.6, 126.2, 126.1, 125.4,
1222.9, 122.0, 121.1, 34.1, 31.2, 24.5, 22.3, 13.9 ppm; MS m/z (%) =
418 (M+, 8.57), 320 (100); IR (neat) 2957, 2930, 1758, 1624, 1500,
1457, 1378, 1302, 1139, 1095, 978, 952, 877, 760, 705 cm−1; HRMS
calcd for C30H26O2 (M+) 418.1933, found 418.1941.
5-Phenyl-1,2-benzanthracene-6-yl Benzoate (2j). The reaction of
Mn(OAc)3·2H2O (85 mg, 0.48 mmol), 1a (61 mg, 0.2 mmol), and
benzoic acid (1 g, 8.2 mmol) in THF (1 mL) afforded 2a (9 mg, 12%)
and 2j (51 mg, 60%) as a white solid (eluent, petroleum ether/CH2Cl2 =
10:1): mp 200−202 °C (petroleum ether); 1H NMR (400 MHz,
CDCl3, 25 °C) δ = 9.22 (s, 1H), 8.88 (d, J = 8.4 Hz, 1H), 8.37 (s, 1H),
8.10 (d, J = 8.4 Hz, 1H), 8.06−8.02 (m, 2H), 7.93 (d, J = 8.4 Hz, 1H),
7.67−7.63(m, 1H), 7.59−7.29 (m, 12H) ppm; 13C NMR (100 MHz,
CDCl3, 25 °C) δ = 165.2, 142.6, 135.5, 133.4, 132.1, 132.0, 130.2, 130.1,
129.6, 129.4, 129.3, 129.2, 128.5, 128.3, 128.2, 128.2, 127.6, 127.4, 127.2,
126.6, 126.2, 126.1, 125.4, 123.0, 122.0, 121.2 ppm; MS m/z (%) = 425
(M + 1+, 10.37),105 (100); IR (neat) 2982, 1736, 1600, 1497, 1448,
1247, 1180, 1114, 1082, 1022, 882, 736, 703, cm−1; HRMS calcd for
C31H20O2 (M+) 424.1463, found 424.1460.
(400 MHz, CD3COCD3, 25 °C) δ = 11.57 (s, 1H), 9.40 (s, 1H),
9.01−8.96 (m, 2H), 8.80 (d, J = 8.0 Hz, 1H), 8.55 (d, J = 8.0 Hz, 1H),
8.22−8.19 (m, 1H), 8.09−8.05 (m, 1H), 7.79−7.70 (m, 2H), 7.61−
7.54 (m, 3H), 7.45−7.33 (m, 2H) ppm; 13C NMR (100 MHz,
CD3COCD3, 25 °C) δ = 139.8, 135.0, 132.8, 132.7, 131.6, 129.5,
128.7, 128.3, 127.1, 126.5, 125.5, 124.9, 124.7, 124.6, 124.4, 123.8,
123.2, 122.2, 121.2, 120.7, 112.6 ppm; MS m/z (%) = 317 (M+, 100);
IR (neat) 3439, 3405, 3051, 1606, 1526, 1428, 1309, 871, 749 cm−1
HRMS calcd for C24H15N (M+) 317.1204, found 317.1210.
;
Synthetic Utilities of 2a. Synthesis of 5,6-Diphenyl-1,2-
benzanthracene (5a). Representative General Procedure for the
Preparation of 6-(Aryl)-5-phenyltetraphenes 5a−5e. A rubber-
capped Schlenk vessel containing 5-phenyl-1,2-benzanthracene-6-yl
acetate (2a) (36 mg, 0.1 mmol), phenylboronic acid (4a) (37 mg, 0.3
mmol), K3PO4 (127 mg, 0.6 mmol), and Ni(PCy3)2Cl2 (3 mg, 0.005
mmol) was degassed and backfilled with nitrogen for three times, then
1,4-dioxane (1 mL) was added to the Schlenk vessel. The resulting
mixture was then allowed to stir at 110 °C. After 20 h, the reaction was
complete as monitored by TLC, the reaction mixture was filtered
through a short pad of silica gel. The filtrate was concentrated under
reduced pressure, and the residue was purified by silica gel
chromatography (petroleum ether/CH2Cl2 = 10:1) to afford 5a (25
1
mg, 66%) as a white solid: mp 206−208 °C (petroleum ether); H
NMR (400 MHz, CDCl3, 25 °C) δ = 9.26 (s, 1H), 8.93 (d, J = 8.4 Hz,
1H), 8.11 (d, J = 8.4 Hz, 1H), 8.00 (s, 1H), 7.81 (d, J = 8.8 Hz, 1H),
7.69−7.64 (m, 1H), 7.55−7.42 (m, 4H), 7.30−7.15 (m, 10H) ppm;
13C NMR (100 MHz, CDCl3, 25 °C) δ = 139.6, 139.5, 137.1, 132.2,
131.8, 131.6, 131.1, 131.0, 130.9, 130.2, 128.6, 128.2, 128.1, 128.0,
127.7, 127.6, 127.0, 126.8, 126.7, 126.6, 126.5, 125.9, 125.7, 122.8,
121.3 ppm; MS m/z (%) = 380 (M+, 11.65), 43 (100); IR (neat)
3054, 1599, 1491, 1470, 1071, 1029, 953, 908, 787, 701 cm−1; HRMS
calcd for C30H20 (M+) 380.1565, found 380.1567.
Phenyl-6-(phenylsulfonyl)-1,2-benzanthracene (2k). The reac-
tion of Mn(OAc)3·2H2O (85 mg, 0.48 mmol), 1a (61 mg, 0.2
mmol), and PhSO2Na (49 mg, 0.3 mmol) in HOAc (2 mL) afforded
2a (5 mg, 7%) an 2k (44 mg, 50%) as a white solid (eluent, petroleum
The following compounds were prepared according to this
procedure.
1
ether/AcOEt = 10:1): mp 196−197 °C (petroleum ether); H NMR
6-(4-Fluorophenyl)-5-phenyl-1,2-benzanthracene (5b). The reac-
tion of 2a (36 mg, 0.1 mmol), 4-fluorophenylboronic acid (4b) (42
mg, 0.3 mmol), K3PO4 (127 mg, 0.6 mmol), and Ni(PCy3)2Cl2 (3 mg,
0.005 mmol) in 1,4-dioxane (1 mL) afforded 5b (30 mg, 75%) as a
white solid (eluent, petroleum ether/CH2Cl2 = 10:1): mp 212−
(400 MHz, CDCl3, 25 °C) δ = 9.56 (s, 1H), 9.19 (s, 1H), 8.84 (d, J =
8.0 Hz, 1H), 8.06 (d, J = 8.0 Hz, 1H), 8.01 (d, J = 8.0 Hz, 1H), 7.77−
7.72 (m, 3H), 7.60−7.54 (m, 2H), 7.49−7.28 (m, 10H) ppm; 13C
NMR (100 MHz, CDCl3, 25 °C) δ = 144.5, 143.6, 137.4, 132.5, 132.4,
131.8, 131.5, 131.5, 130.0, 130.0, 129.8, 128.9, 128.7, 128.6, 127.7,
127.6, 127.4, 127.0, 127.0, 126.4, 126.3, 124.4, 122.6, 121.8 ppm; MS
m/z (%) = 445 (M + 1+, 24.08), 303 (100); IR (neat) 2983, 2903,
1736, 1491, 1445, 1400, 1319, 1251, 1149, 1079, 882, 840, 754, 725,
703 cm−1; HRMS calcd for C30H20O2S (M+) 444.1184, found
444.1166.
1
214 °C (petroleum ether); H NMR (400 MHz, CDCl3, 25 °C) δ =
9.26 (s, 1H), 8.92 (d, J = 8.0 Hz, 1H), 8.12 (d, J = 8.8 Hz, 1H), 7.96
(s, 1H), 7.83 (d, J = 8.0 Hz, 1H), 7.69−7.65 (m, 1H), 7.55−7.44
(m, 4H), 7.28−7.12 (m, 7H), 6.97(t, J = 8.4 Hz, 2 H) ppm; 13C NMR
(100 MHz, CDCl3, 25 °C) δ = 161.6 (d, J = 244.0 Hz), 139.4, 137.5,
136.1, 135.4 (d, J = 2.3 Hz), 132.7, 132.6, 132.1, 131.9, 131.6, 130.9,
130.3, 128.6, 128.2, 128.1, 128.1, 127.8, 127.1, 126.8, 126.5 (d, J = 8.0
Hz), 126.0, 125.8, 122.8, 121.5, 114.8 (d, J = 21.1 Hz) ppm; MS m/z
(%) = 398 (M+, 9.78), 69 (100); IR (neat) 3053, 1601, 1548, 1505,
1219, 1155, 953, 863, 767, 702 cm−1; HRMS calcd for C30H19F (M+)
398.1471, found 398.1478.
5-Phenyl-6-(phenylsulfonyl)-1,2-benzanthracene (2l). The reac-
tion of Mn(OAc)3·2H2O (85 mg, 0.48 mmol), 1a (61 mg, 0.2 mmol),
and Na N3 (20 mg, 0.3 mmol) in HOAc (2 mL) afforded 2a (1 mg,
1%) and 2l (37 mg, 54%) as a white solid (eluent, petroleum ether):
1
mp 236−238 °C (petroleum ether); H NMR (400 MHz, CDCl3,
25 °C) δ = 9.15 (s, 1H), 8.85 (s, 1H), 8.80 (d, J = 8.0 Hz, 1H), 8.13−
8.05 (m, 2H), 7.63−7.41 (m, 10H) ppm; 13C NMR (100 MHz,
CDCl3, 25 °C) δ = 135.4, 132.3, 132.1, 132.0, 131.6, 131.2, 129.9,
128.9, 128.8, 128.7, 128.5, 128.4, 128.2, 127.3, 126.4, 126.4, 126.2,
125.8, 123.3, 122.8, 121.6 ppm; MS m/z (%) = 345 (M+, 14.21), 317
(100); IR (neat) 3055, 2923, 2853, 2114, 1601, 1498, 1450, 1350,
1312, 1279, 883, 760, 701 cm−1; HRMS calcd for C24H15N3 (M+)
345.1266, found 345.1253.
5-Phenyl-6-p-tolyl-1,2-benzanthracene (5c). The reaction of 2a
(36 mg, 0.1 mmol), p-tolylboronic acid (4c) (41 mg, 0.3 mmol),
K3PO4 (127 mg, 0.6 mmol), and Ni(PCy3)2Cl2 (3 mg, 0.005 mmol) in
1,4-dioxane (1 mL) afforded 5c (29 mg, 74%) as a white solid (eluent,
petroleum ether/CH2Cl2 = 10:1): mp 240−242 °C (petroleum ether);
1H NMR (400 MHz, CDCl3, 25 °C) δ = 9.25 (s, 1H), 8.92 (d, J = 8.4
Hz, 1H), 8.11 (d, J = 8.4 Hz, 1H), 8.03 (s, 1H), 7.82 (d, J = 8.8 Hz,
1H), 7.67−7.63 (m, 1H), 7.52−7.43 (m, 4H), 7.25−7.16 (m, 5H),
7.08−7.05 (m, 4H), 2.33 (s, 3H) ppm; 13C NMR (100 MHz, CDCl3,
25 °C) δ = 139.7, 137.2, 137.0, 136.5, 135.9, 132.3, 131.9, 131.6, 131.1,
131.0, 130.9, 130.2, 128.7, 128.4, 128.2, 128.1, 128.0, 127.6, 126.9,
126.8, 126.6, 126.4, 125.8, 125.6, 122.7, 121.3, 21.3 ppm; MS m/z (%)
= 394 (M+, 24.46), 43 (100); IR (neat) 3053, 2985, 1512, 1503, 1120,
1106, 986, 865, 778 cm−1; HRMS calcd for C31H22 (M+) 394.1722,
found 394.1720.
Synthetic Utilities of 2l. Synthesis of 11H-Benzo[c]naphtho-
[2,3-a]carbazole (3a). A rubber-capped Schlenk vessel containing 5-
phenyl-6-(phenylsulfonyl)-1,2-benzanthracene (2l) (69 mg, 0.2 mmol)
was degassed and backfilled with nitrogen three times, then toluene
(5 mL) and HOAc (0.1 mL) were added to the Schlenk vessel. The
resulting mixture was then allowed to stir at 110 °C. After 5 h, the
reaction was complete as monitored by TLC. The reaction solution
was diluted with ether (20 mL) and washed with a saturated aqueous
NaHCO3 solution (20 mL × 3). The combined organic layer was
dried over anhydrous MgSO4. The solvent was removed under
6-(4-Methoxyphenyl)-5-phenyl-1,2-benzanthracene (5d). The
reaction of 2a (36 mg, 0.1 mmol), 4-methoxyphenylboronic acid
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(4d) (46 mg, 0.3 mmol), K3PO4 (127 mg, 0.6 mmol), and
Ni(PCy3)2Cl2 (3 mg, 0.005 mmol) in 1,4-dioxane (1 mL) afforded
5d (27 mg, 66%) as a white solid (eluent, petroleum ether/CH2Cl2 =
10:1): mp 250−252 °C (petroleum ether); 1H NMR (400 MHz,
CDCl3, 25 °C) δ = 9.27 (s, 1H), 8.94 (d, J = 8.0 Hz, 1H), 8.13 (d, J =
8.4 Hz, 1H), 8.04 (s, 1H), 7.84 (d, J = 8.4 Hz, 1H), 7.55−7.51 (m,
1H), 7.54−7.44 (m, 4H), 7.28−7.10 (m, 7H), 6.81 (d, J = 8.8 Hz, 2
H), 3.80 (s, 3H) ppm; 13C NMR (100 MHz, CDCl3, 25 °C) δ = 158.1,
139.8, 137.3, 136.9, 132.3, 132.1, 131.9, 131.8, 131.6, 131.3, 130.9,
130.2, 128.7, 128.2, 128.1, 128.0, 127.7, 127.0, 126.8, 126.6, 126.4,
125.9, 125.6, 122.8, 121.3, 113.2, 55.1 ppm; MS m/z (%) = 410 (M+,
9.23), 43 (100); IR (neat) 3055, 1607, 1507, 1441, 1285, 1244, 1179,
1106, 1076, 1029, 758 cm−1; HRMS calcd for C31H22O (M+)
410.1671, found 410.1670.
(%) = 452 (M+, 16.19), 319 (100); IR (neat) 3975, 2903, 1451, 1415,
1208, 1135, 1070, 942, 905, 820 cm−1; HRMS calcd for C25H15O3F3S
(M+) 452.0694, found 452.0702.
Synthetic Utilities of 7a. (E)-5-Phenyl-6-styryl-1,2-benzan-
thracene (5f). A rubber-capped Schlenk vessel containing 5-phenyl-
1,2-benzanthracene-6-yl trifluoromethanesulfonate (7a) (45 mg, 0.1
mmol), (E)-styrylboronic acid (30 mg, 0.2 mmol), K3PO4 (64 mg, 0.3
mmol), and Pd(PPh3)4 (6 mg, 0.005 mmol) was degassed and
backfilled with nitrogen three times. Then 1,4-dioxane (1 mL) was
added to the Schlenk vessel. The resulting mixture was then allowed to
stir at 110 °C. After 20 h, the reaction was complete as monitored by
TLC. The reaction mixture was filtered through a short pad of silica
gel. The filtrate was concentrated under reduced pressure, and the
residue was purified by silica gel chromatography (petroleum ether/
CH2Cl2 = 10:1) to afford 5f (30 mg, 73%) as a white solid: mp 165−
6-(3-Methoxyphenyl)-5-phenyl-1,2-benzanthracene (5e). The re-
action of 2a (36 mg, 0.1 mmol), 4-methoxyphenylboronic acid (4e)
(46 mg, 0.3 mmol), K3PO4 (127 mg, 0.6 mmol), and Ni(PCy3)2Cl2
(3 mg, 0.005 mmol) in 1,4-dioxane (1 mL) afforded 5e (25 mg, 61%)
as a white solid (eluent, petroleum ether/CH2Cl2 = 10:1): mp 175−
1
167 °C (petroleum ether); H NMR (400 MHz, CDCl3, 25 °C) δ =
9.22 (s, 1H), 8.86 (d, J = 8.0 Hz, 1H), 8.80 (s, 1H), 8.11 (d, J = 8.0
Hz, 1H), 8.00 (d, J = 8.0 Hz, 1H), 7.62−7.20 (m, 15H), 7.16 (d,
J = 16.8 Hz, 1H), 6.67 (d, J = 16.8 Hz, 1H), ppm; 13C NMR (100
MHz, CDCl3, 25 °C) δ = 139.7, 137.6, 136.5, 135.8, 132.4, 132.1,
132.0, 131.6, 130.8, 130.0, 129.5, 128.8, 128.6, 128.2, 128.1, 127.8,
127.5, 127.0, 126.9, 126.8, 126.6, 126.3, 125.9, 125.8, 125.6, 122.7,
121.7 ppm; MS m/z (%) = 406 (M+, 22.11), 84 (100); IR (neat)
3055, 1599, 1490, 1442, 1072, 908, 880, 729, 692, 669 cm−1; HRMS
calcd for C32H22 (M+) 406.1722, found 406.1726.
1
176 °C (petroleum ether); H NMR (400 MHz, CDCl3, 25 °C) δ =
9.25 (s, 1H), 8.921 (d, J = 8.4 Hz, 1H), 8.11 (d, J = 8.4 Hz, 1H), 8.07
(s, 1H), 7.84 (d, J = 8.8 Hz, 1H), 7.69−7.63 (m, 1H), 7.55−7.42 (m,
4H), 7.28−7.14 (m, 6H), 6.85−6.75 (m, 3H), 3.68 (s, 3H) ppm; 13C
NMR (100 MHz, CDCl3, 25 °C) δ = 159.0,140.9, 139.5, 137.0, 136.9,
132.2, 131.9, 131.6, 130.9, 130.8, 130.7, 130.2, 128.6, 128.6, 128.2,
128.1, 128.0, 127.7, 127.6, 127.0, 126.8, 126.7, 126.5, 125.9, 125.7,
123.8, 122.8, 121.3, 116.6, 112.5, 55.1 ppm; MS m/z (%) = 410 (M+,
3.73), 84 (100); IR (neat) 3054, 1598, 1577, 1489, 1313, 1250, 1178,
1408, 908, 732, 704 cm−1; HRMS calcd for C31H22O (M+) 410.1671,
found 410.1675.
The following compounds were prepared according to this
procedure.
6-Pentyl-5-phenyl-1,2-benzanthracene (5g). A rubber-capped
Schlenk vessel containing 5-phenyl-1,2-benzanthracene-6-yl trifluor-
omethanesulfonate (7a) (45 mg, 0.1 mmol), butylboronic acid (20
mg, 0.2 mmol), K3PO4 (64 mg, 0.3 mmol), and Pd(PPh3)4 (6 mg,
0.005 mmol) was degassed and backfilled with nitrogen three times,
then 1,4-dioxane (1 mL) was added to the Schlenk vessel. The
resulting mixture was then allowed to stir at 110 °C. After 20 h, the
reaction was complete as monitored by TLC, the reaction mixture was
filtered through a short pad of silica gel. The filtrate was concentrated
under reduced pressure, and the residue was purified by silica gel
chromatography (petroleum ether/CH2Cl2 = 10:1) to afford 5g (27
Hydrolysis of 2a. Synthesis of 5-Phenyl-1,2-benzanthracene-
6-ol (6a). A rubber-capped Schlenk vessel containing 5-phenyl-1,2-
benzanthracene-6-yl acetate (2a) (72 mg, 0.2 mmol) and NaOH (80
mg, 2.0 mmol) was degassed and backfilled with nitrogen three times,
then methanol (2 mL) was added to the Schlenk vessel. The resulting
mixture was then allowed to stir at 25 °C. After 2 h, the reaction was
complete as monitored by TLC, and the reaction mixture was filtered
through a short pad of silica gel. The filtrate was concentrated under
reduced pressure, and the residue was purified by silica gel
chromatography (petroleum ether/CH2Cl2 = 10:1) to afford 6a (56
1
mg, 74%) as a colorless oil: H NMR (400 MHz, CDCl3, 25 °C) δ =
9.25 (s, 1H), 8.86 (d, J = 8.4 Hz, 1H), 8.60 (s, 1H), 8.15−8.05 (m,
2H), 7.61−7.34 (m, 7H), 7.33−7.26(m, 2H), 7.25 (d, J = 8.4 Hz, 1H),
2.95−2.89 (m, 2H), 1.69−1.64 (m, 2H), 1.39−1.31 (m, 2H), 0.84(t, J
= 7.2 Hz, 3 H) ppm; 13C NMR (100 MHz, CDCl3, 25 °C) δ = 140.5,
136.6, 134.7, 132.7, 132.0, 131.4, 130.1, 129.6, 129.0, 128.4, 128.2,
128.1, 127.7, 127.0, 126.8, 125.9, 125.7, 125.7, 123.8, 122.6, 121.8,
32.8, 30.3, 23.19, 13.78 ppm; MS m/z (%) 360 (M+, 31.36), 84 (100);
IR (neat) 3054, 2955, 1599, 1492, 1440, 951, 907, 877, 766, 733, 689
cm−1; HRMS calcd for C28H24(M+) 360.1878, found 360.1874.
5-Phenyl-6-(phenylethynyl)-1,2-benzanthracene (5h). A rubber-
capped Schlenk vessel containing 7a (45 mg, 0.1 mmol), Pd(PPh3)4
(6 mg, 0.005 mmol), and AuCl(PPh3) (2 mg, 0.005 mmol) was
degassed and backfilled with nitrogen three times. Then ethynylben-
zene (15 mg, 0.15 mmol), Et3N (30 mg, 0.3 mmol), and DMF (2 mL)
were added to the Schlenk vessel. The resulting mixture was then
allowed to stir at 80 °C for 10 h. After the reaction was complete as
monitored by TLC. The reaction solution was diluted with ether (20
mL) and washed with a saturated aqueous NaHCO3 solution (20 mL
× 3). The combined organic layers were dried over anhydrous MgSO4.
The solvent was removed under reduced pressure, and the residue
was purified by a flash column chromatography (petroleum ether/
CH2Cl2 = 10:1) to afford 5h (29 mg, 71%) as a white solid: mp 140−
1
mg, 88%) as a white solid: mp 120−121 °C (petroleum ether); H
NMR (400 MHz, CDCl3, 25 °C) δ = 9.16 (s, 1H), 8.87 (s, 1H), 8.79
(d, J = 8.0 Hz, 1H), 8.13−8.07 (m, 2H), 7.63−7.32 (m, 8H), 7.43−
7.34(m, 1H), 7.33−7.31(m, 1H), 5.51 (s, 1H) ppm; 13C NMR (100
MHz, CDCl3, 25 °C) δ = 145.9, 134.4, 132.7, 132.2, 131.9, 131.4,
129.8, 129.2,128.6, 128.4, 128.3, 127.2, 126.9, 126.1, 125.9, 125.5,
124.3, 124.0, 122.8, 122.0, 121.54, 116.5 ppm; MS m/z (%) = 320
(M+, 42.81), 57 (100); IR (neat) 3529, 3054, 1623, 1503, 1314, 1254,
1114, 1068, 884, 754 cm−1; HRMS calcd for C24H16O (M+) 320.1201,
found 320.1194.
Esterification of 6a. Synthesis of 5-Phenyl-1,2-benzanthra-
cene-6-yl trifluoromethanesulfonate (7a). A rubber-capped Schlenk
vessel containing 6a (64 mg, 0.2 mmol) was degassed and backfilled
with nitrogen three times, then THF (2 mL) was added to the Schlenk
vessel. After being stirred for 0.5 h at −78 °C, n-BuLi (0.18 mL, 0.4
mmol, 2.25 M in hexane) was added. Then after another 0.5 h, Tf2O
(113 mg, 0.4 mmol, 0.067 mL) was added. The resulting mixture was
then allowed to stir from −78 °C to room temperature for 10 h. After
the reaction was complete as monitored by TLC, the reaction solution
was diluted with ether (20 mL) and washed with a saturated aqueous
NaHCO3 solution (20 mL × 3). The organic layers were dried over
anhydrous MgSO4. The solvent was removed under reduced pressure,
and the residue was purified by a flash column chromatography
(petroleum ether/CH2Cl2 = 10:1) to afford 7a (84 mg, 93%) as a
white solid: mp 188−189 °C (petroleum ether); 1H NMR (400 MHz,
CDCl3, 25 °C) δ = 9.20 (s, 1H), 8.85 (d, J = 8.0 Hz, 1H), 8.75 (s,
1H), 8.15−8.09 (m, 2H), 7.73−7.69 (m, 1H), 7.65−7.48 (m, 9H)
ppm; 13C NMR (100 MHz, CDCl3, 25 °C) δ = 141.3, 133.4, 132.3,
132.1, 131.7, 131.4, 131.1, 130.0, 129.2, 128.7, 128.5, 128.2, 127.9,
127.6, 127.0, 126.8, 124.3, 123.0, 122.1, 122.1, 118.2 ppm; MS m/z
1
142 °C (petroleum ether); H NMR (400 MHz, CDCl3, 25 °C) δ =
9.21 (s, 1H), 9.08 (s, 1H), 8.87 (d, J = 8.4 Hz, 1H), 8.16−8.13 (m,
2H), 7.70−7.7.64 (m, 1H), 7.62−7.49 (m, 9H), 7.32−7.28 (m, 5H)
ppm; 13C NMR (100 MHz, CDCl3, 25 °C) δ = 143.2, 139.8, 132.2,
132.0, 131.6, 131.5, 130.6, 130.5, 129.0, 128.3, 128.2, 128.1, 128.0,
127.5, 127.4, 127.1, 126.1, 126.1, 126.0, 123.5, 122.9, 121.6, 119.1,
98.3, 87.9 ppm; MS m/z (%) = 404 (M+, 32.09), 43 (100); IR (neat)
3055, 1598, 1492, 1442, 1323, 1279, 1073, 908, 882, 753, 694 cm−1
HRMS calcd for C32H20 (M+) 404.1565, found 404.1563.
;
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The Journal of Organic Chemistry
Article
1-((5-Phenyl-1,2-benzanthracene-6-yl)ethynyl)cyclohexanol
(5i). A rubber-capped Schlenk vessel containing 7a (45 mg, 0.1
mmol), Pd(PPh3)4 (6 mg, 0.005 mmol), and AuCl(PPh3) (2 mg,
0.005 mmol) was degassed and backfilled with nitrogen three times,
then 1-ethynylcyclohexanol (19 mg, 0.15 mmol), Et3N (30 mg, 0.3
mmol), and DMF (2 mL) were added to the Schlenk vessel. The
resulting mixture was then allowed to stir at 80 °C for 10 h. After the
reaction was complete as monitored by TLC, the reaction solution was
diluted with ether (20 mL) and washed with a saturated aqueous
NaHCO3 solution (20 mL × 3). The combined organic layer was
dried over anhydrous MgSO4. The solvent was removed under
reduced pressure, and the residue was purified by a flash column
chromatography (petroleum ether/CH2Cl2 = 10:1) to afford 5i (21
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mg, 50%) as a colorless oil: H NMR (400 MHz, CDCl3, 25 °C) δ =
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130.3, 130.2, 129.0, 128.3, 128.2, 128.0, 127.9, 127.5, 127.4, 127.1,
126.1, 126.0, 122.9, 121.6, 118.6, 101.8, 82.3, 69.6, 39.9, 25.1, 23.3
ppm; MS m/z (%) = 426 (M+, 34.61), 43 (100); IR (neat) 3398,
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ASSOCIATED CONTENT
■
S
* Supporting Information
1
Copies of H and 13C NMR spectra for 2, 3, 5−7, X-ray
crystallographic data (CIF file) for 2a. This material is available
free of charge via the Internet at http://pubs.acs.org.
AUTHOR INFORMATION
Corresponding Author
*E-mail: wululing@zju.edu.cn.
Notes
■
(29) Melikyan, G. G. Org. React. 1997, 49, 427−670.
(30) Fristad, W. E.; Peterson, J. R.; Ernst, A. B. Tetrahedron 1986, 42,
3429−3442.
⊥Professor Huang passed away on March 6, 2010. He was fully
in charge of this project. Professor Luling Wu is helping to
finish all the projects with assistance from Professor Shengming
Ma.
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ACKNOWLEDGMENTS
■
We are grateful to the National Natural Science Foundation of
China (Project Nos. 20872127, 20732005, and J0830431) and
National Basic Research Program of China (973 Program,
2009CB825300) and CAS Academician Foundation of
Zhejiang Province and the Fundamental Research Funds for
the Central Universities for financial support.
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