CuX2-mediated [4+2] benzannulation as a new synthetic tool for stereoselective construction of haloaromatic compounds

Article abstract of DOI:10.1016/j.tet.2009.09.061

The CuX₂-mediated reaction of enynal units, including ortho-alkynylbenzaldehydes, with alkynes gives a variety of haloaromatic compounds stereoselectively in good to high yields. 2,2′-Binaphthyl skeletons are also readily prepared by the reacti

Full text of DOI:10.1016/j.tet.2009.09.061

Tetrahedron 65 (2009) 9575–9582
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CuX2-mediated [4þ2] benzannulation as a new synthetic tool
for stereoselective construction of haloaromatic compounds
,b,
Yukie Isogai a, Menggenbateer a, F. Nawaz Khan a, Naoki Asao a
*
a Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
b Research and Analytical Center for Giant Molecules, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
a r t i c l e i n f o
a b s t r a c t
Article history:
The CuX2-mediated reaction of enynal units, including ortho-alkynylbenzaldehydes, with alkynes gives
a variety of haloaromatic compounds stereoselectively in good to high yields. 2,20-Binaphthyl skeletons
are also readily prepared by the reaction of ortho-alkynylbenzaldehydes and diynes. The method was
applied to the synthesis of poly-substituted tetracene derivatives.
Received 11 August 2009
Received in revised form
15 September 2009
Accepted 16 September 2009
Available online 18 September 2009
Ó 2009 Elsevier Ltd. All rights reserved.
1. Introduction
compounds.8 While exploring the scope of these unprecedented
reactions, we found that a chlorinated naphthalene was formed in
Haloaromatic compounds are extremely valuable not only as
precursors of aryl-metals but also as substrates for transition
metal-catalyzed cross coupling reactions.1 They are also important
structural motifs in a wide variety of natural products and func-
tional materials.2 Direct electrophilic halogenations of aromatic
compounds and halogenation of aryldiazonium salts have been
widely used for preparation of those useful compounds.3,4 How-
ever, a drawback of these methods is often the difficulty in
controlling chemo- and regioselectivity. While functional group-
directed ortho-metalation followed by nucleophilic halogenation as
well as transition metal-catalyzed halogenation through C–H acti-
vation are regioselective, suitable functional groups are essential
for these protocols.5,6 Herein, we report the CuX2-mediated ben-
zannulation reaction of enynal units, including ortho-alky-
nylbenzaldehydes, with alkynes, leading to regioselective
formation of chloro-, and bromo aromatic compounds through the
cleavage of a triple bond of enynal units in good to high yields.7
Furthermore, we applied the current transformation to the syn-
thesis of halogenated 2,20-binaphthyls and tetracene derivatives
(Scheme 1).
the reaction of ortho-alkynylbenzaldehyde 1a with phenyl-
acetylene 2a in the presence of CuCl2. This result prompted us to
investigate the reaction and the results are summarized in Table 1.
When the reaction of 1a with 2a was carried out in the presence of
1.2 equiv of CuCl2 in (CH2Cl)2 at 70 ꢀC for 8 h, 3a was obtained in
51% yield (entry 1). The chemical yield was increased to 78% by
using 2 equiv of CuCl2 (entry 2). Besides (CH2Cl)2, CH3CN and
CH3NO2 are suitable solvents (entries 3–4). The reaction of 1b,
having a butyl group at the terminus of the alkynyl part, also gave
3a in 67% yield (entry 5). As for alkynes 2, not only aromatic alkynes
but also aliphatic alkynes are applicable for the present benzan-
nulation. For instance, the reaction with 1-hexyne gave 3d in 78%
yield (entry 8). Even with sterically bulky 3,3-dimethylbut-1-yne
CuX2
X
CHO
X
2. Results and discussion
CuX2
X
R
2.1. Synthesis of 1-halonaphthalenes
I
We have reported that Lewis acid-catalyzed benzannulations
between enynal units and alkynes gave a wide range of aromatic
CuCl2
Cl
(X = Cl, Br)
* Corresponding author. Tel.: þ81 22 795 3898; fax: þ81 22 795 3899.
E-mail address: asao@m.tains.tohoku.ac.jp (N. Asao).
Scheme 1. CuX2-mediated [4þ2] benzannulation.
0040-4020/$ – see front matter Ó 2009 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2009.09.061

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Y. Isogai et al. / Tetrahedron 65 (2009) 9575–9582
Table 1
CuCl2-mediated benzannulation between 1 and alkynes 2a
R2
R2
R1
CHO
CuCl2
+
R1
Cl
R
1a: R = Ph
1b: R = C4H9
2
3
Entry
1
2
R1
R2
Solvent
Condition
Yieldb 3 (%)
1c
2
3
4
5
6
7
8
1a
1a
1a
1a
1b
1a
1a
1a
1a
1a
1a
1a
1a
1a
2a
2a
2a
2a
2a
2b
2c
2d
2e
2f
Ph
Ph
Ph
Ph
H
H
H
H
H
H
H
H
H
H
Me
C3H7
H
(CH2Cl)2
(CH2Cl)2
CH3CN
CH3NO2
CH3CN
(CH2Cl)2
(CH2Cl)2
CH3NO2
CH3NO2
CH3NO2
(CH2Cl)2
(CH2Cl)2
(CH2Cl)2
(CH2Cl)2
70 ꢀC, 8 h
70 ꢀC, 6 h
70 ꢀC, 3 h
80 ꢀC, 4 h
70 ꢀC, 3 h
70 ꢀC, 5.5 h
70 ꢀC, 4 h
80 ꢀC, 3 h
80 ꢀC, 2 h
80 ꢀC, 2 h
70 ꢀC, 3.5 h
70 ꢀC, 16 h
70 ꢀC, 4 h
70 ꢀC, 17 h
3a
3a
3a
3a
3a
3b
3c
3d
3e
3f
51
78
66
85
67
80
70
78
51
25e
74
50
60
70
Ph
p-CF3C6H4
p-MeOC6H4
C4H9
t-Bu
TMS
Ph
C3H7
1-cC6H9
PhCH]CH
9d
10d
11
12
13f
14g
2g
2h
2i
3g
3h
3i
2j
Br
3j
a
Reactions were conducted using 1 (1 equiv), 2 (1.2 equiv), and CuCl2 (2 equiv) unless otherwise mentioned.
b
c
d
e
f
Isolated yield.
1.2 equiv of CuCl2 was used.
5 equiv of 2 was used.
3f0 was obtained in 40% yield.
1-cC6H9¼1-cyclohexenyl.
2 equiv of 2j was used.
g
2e, the reaction proceeded to give 3e although the chemical yield
mediated reaction was an alternative method for formation of 4. For
example, the reaction of 1a with 2a in the presence of a 1:2 mixture
of CuCl2 and LiBr afforded 4a in 59% yield along with a small
amount of 3a (5%). Barluenga and Larock independently have
reported the iodonium ion-mediated benzannulations between
ortho-alkynylbenzaldehydes and alkynes to produce 1-iodonaph-
thalene products effectively.9 The present method can be used as
a complementary approach for preparation of a wide range of
halonaphthalene compounds.
Previously, we have reported the Cu(OTf)2-catalyzed benzan-
nulation of enynal units with alkynes, leading to aromatic com-
pounds through the cleavage of a triple bond of enynal units.8
Probably, products 3 and 4 might be produced similarly by the
dissociation of the alkynyl part of 1. We then conducted the CuCl2-
mediated reaction of 1b with 2a in CDCl3 to investigate the reaction
mechanism with NMR experiments. After completion of the re-
action, 1H NMR spectrum of the reaction mixture indicated the
generation of 3a in 68% yield together with pentanoyl chloride 5a in
the same yield as shown in Scheme 3.
was low (22%), probably due to its low boiling point. Indeed, the
chemical yield was increased up to 51% by using an excess amount
of 2e (entry 9). On the other hand, in the case of trimethylsilyl-
acetylene 2f, the reversal of the selectivity was observed, and the
regioisomer of 3f (3f0: R1¼H, R2¼TMS) was obtained pre-
dominantly (3f:3f0¼1:1.6). The similar reversal has been observed
previously in the gold-catalyzed benzannulation.8 With the present
method, 2,3-disubstituted chloronaphthalenes can be prepared by
use of internal alkynes (entries 11–12). In comparison with prop-1-
ynylbenzene 2g, oct-4-yne 2h is less reactive, probably due to the
steric effect of two propyl groups of 2h. It is worth mentioning that
one more halogen can be introduced on the acene skeletons
regioselectively with 1-halo-alkynes. For example, the reaction
with (4-bromobut-1-en-3-ynyl)benzene 2j gave 3-bromo-1-
chloro-2-styrylnaphthalene 3j in 70% yield (entry 14).
CuBr2, as well as CuCl2, promoted the reaction to give bromo-
substituted naphthalenes although the chemical yields of products
were slightly lower than those of chloro-substituted analogs
(Scheme 2). We also found that addition of LiBr to the CuCl2-
CHO
H
CuCl2
CHO
H
+
CDCl3
70 ºC, 3 h
+
C4H9
R
Ph
Br
Ph
R
1b
2a
1a
2a,d
4a: R = Ph
4b: R = C4H9
O
+
Ph
C4H9
Cl
CuBr2/CH3NO2, 60 ºC, 2 h
CuBr2/CH3NO2, 60 ºC, 2 h
CuCl2-2LiBr/CH3CN, 80 ºC, 5 h
4a: 62%
Cl
3a 68%
4b: 50%
5a 68%
4a: 59% 3a: 5%
Scheme 3. Detection of 5a with 1H NMR experiments.
Scheme 2. Construction of bromo-substituted naphthalenes.

Y. Isogai et al. / Tetrahedron 65 (2009) 9575–9582
9577
On the basis of these results, we proposed a reaction mechanism
as shown in Scheme 4. The coordination of the triple bond of 1 to
CuCl2 enhances the electrophilicity of the alkyne, and the sub-
sequent nucleophilic attack of the carbonyl oxygen to the electron
deficient alkyne forms the ate complex 6, which is converted to the
intermediate 7 by chlorination. Then, addition of alkyne 2 to 7
occurs to form the bicyclic intermediate 9 through the formation of
8. The regioselectivities observed in Table 1 are accounted for by
intervention of 8. When R1 are aryl or alkyl groups, the in-
termediate 8 would be stabilized by resonance or inductive effects
of R1. On the other hand, the predominant formation of 3f0 in the
reaction of trimethylsilylacetylene 2f is ascribed to the well-known
on the naphthalene skeleton, which might be available for the
second benzannulation. As we expected, when 1a (2.5 equiv) was
treated with diyne 2k (1 equiv) in the presence of CuCl2 in CH3NO2
at 100 ꢀC, 2,20-binaphthyl 12a was obtained in 70% yield (Scheme
6). It is worth mentioning that the reaction proceeded in a highly
stereoselective manner because 12a is one of the three possible
isomers (12a0 and 12a00). The reactions of 1a with 2l also proceeded
with CuCl2 or CuBr2 smoothly to give 12b and 12c in 65% and 45%
yields, respectively. Although aryl–aryl bond formation has been
studied well as the most common synthetic route for biaryl com-
pounds,11 the present method can be used as an alternative ap-
proach. The structure of 12a was confirmed by X-ray
crystallographic analysis as shown in Figure 1.
b
-silyl effect: a carbocation b to trimethylsilyl group is stabilized
significantly.10 Then, the attack of Clꢁ to the carbon of RCO of 9
occurs and the resulting intermediate 10 undergoes retro Diels–
Alder reaction to produce 3 and 5.8,9 It is well known that NCS is
a chlorinating agent in organic synthesis. However, no reaction
took place between 1a and 2a in the presence of 2 equiv of NCS,
instead of CuCl2, in CH3NO2 even under 80 ꢀC for 18 h. This result
clearly suggested that CuCl2 exhibits dual roles in the current re-
action; it acts as an alkynophilic Lewis acid and as a chlorinating
agent.
R
R
CHO
X
CuX2
+
(CH2Cl)2
100 ºC
1.5 h
X
Ph
R
R
1a
2k: R = C4H9
2l: R = Ph
12a: R = C4H9, X = Cl
12b: R = Ph, X = Cl
12c: R = Ph, X = Br
CHO
O
CuCl2
CuCl2
R
CuCl2
X
R
-2CuCl
R
R
R
1
6
Cl
R2
O
R
O
Cl
Cl
R1
R2
X
R
X
R
12a'
12a''
X
2
Cl
Cl
R1
Scheme 6. Construction of 2,20-biphenyl skeletons.
7
8
O
R
O
R
Cl
R2
R2
R1
3 + 5
R1
Cl
Cl
9
10
Scheme 4. Plausible reaction mechanism.
2.2. Synthesis of halogenated aromatic compounds
Since halogenated naphthalene derivatives were produced un-
expectedly easily from benzaldehyde derivatives 1a–b, we applied
the present method to the construction of other aromatic skeletons.
The reaction of conjugated enynal 1c with 2a proceeded smoothly
and the corresponding 20-chloro-[1,10;30,100]terphenyl 11 was
obtained in 50% yield (Scheme 5).
CHO
H
CuCl2
+
Ph
Ph
11
Ph
CH3NO2
Cl
Ph
Ph
2a
60 ºC, 2 h
Figure 1. X-ray structure of 12a.
1c
50%
Finally, the method was applied to the synthesis of a tetracene
framework, which has been widely studied as the semiconducting
layers in field effect transistors.12–14 The copper-mediated benz-
annulation of naphthaldehyde derivative 13 with iodo-substituted
conjugated enyne 2m proceeded smoothly and the corresponding
iodo-substituted anthracene product 14 was obtained in 52% yield.
Sonogashira coupling between 14 and phenylacetylene gave 15a in
56% yield, which was aromatized with the gold catalyst to afford
Scheme 5. Construction of benzene frameworks.
Next, we examined the reaction of 1a with conjugated diyne 2k
instead of simple alkynes. We expected that the double benzan-
nulation might occur in this system because the first benzannula-
tion product, derived from 1a and 2k, would have an alkynyl group

9578
Y. Isogai et al. / Tetrahedron 65 (2009) 9575–9582
chloro-substituted tetracene derivative 16a in 75% yield.15 The
propyl-substituted product 16b was also prepared in the similar
way in good yield (Scheme 7).
2.3 mmol), and phenylacetylene (3.8 mL, 34.6 mmol) successively
at room temperature and the mixture was stirred for 1 h at 50 ꢀC. A
saturated aqueous solution of NH4Cl was added, and the mixture
was extracted with ether three times. The combined extracts were
washed with brine, dried (MgSO4), and evaporated to leave the
crude product, which was purified by silica gel column chroma-
tography using a mixture of hexane and ether as eluent to give 1c
(4.1 g, 17.9 mmol) in 78% yield as a yellow solid; 1H NMR (CDCl3,
I
I
CHO
CuCl2
52%
+
400 MHz)
d
10.41 (d, J¼8.0 Hz, 1H), 7.86 (dd, J¼2.0, 7.4 Hz, 1H), 7.61
Cl
C3H7
(d, J¼2.0, 7.6 Hz, 1H), 7.49–7.42 (m, 6H), 6.81 (d, J¼7.6 Hz, 1H); 13C
13
2m
14
NMR (CDCl3, 100 MHz)
d 193.0, 142.4, 135.5, 131.9, 131.0, 130.9,
129.8, 128.8, 128.6, 127.1, 121.5; IR (KBr) 2204, 1661, 1556, 1489,
1448, 1348, 1138, 1074, 827, 758 cmꢁ1; GC–MS (EI) m/z (%) 231
([Mþꢁ1], 53), 203 (100); HRMS (ESI) calcd for ([C17H12OþNa])þ
255.0780, found 255.0781; mp 42–44 ꢀC.
R
R
Pd cat
Cl
4.3. (E)-(4-Bromobut-1-en-3-ynyl)benzene (2j)
15a: R = Ph
56%
To a solution of (E)-(2-bromovinyl)benzene (7.7 mL, 60 mmol) in
THF (150 mL) and Et3N (40 mL) were added PdCl2 (532 mg,
3.0 mmol), PPh3 (1.57 g, 6.0 mmol), CuI (1.14 g, 6.0 mmol), and tri-
methylsilylacetylene (17 mL, 120 mmol) successively at room tem-
perature and the mixture was stirred for 12 h at 60 ꢀC. A saturated
aqueous solution of NH4Cl was added, and the mixture was extrac-
ted with ether three times. The combined extracts were washed
with brine, dried (MgSO4), and evaporated to leave the crude
product, which was purified by silica gel column chromatography
using a mixture of hexane and CH2Cl2 as eluent to give (E)-tri-
methyl(4-phenylbut-3-en-1-ynyl)silane (7.3 g, 36.4 mmol) in 61%
yield. To a solution of 85% KOH (666 mg, 10.0 mmol) in MeOH
(45 mL) was added (E)-trimethyl(4-phenylbut-3-en-1-ynyl)silane
(3.65 g, 18.2 mmol) at 0 ꢀC and the mixture was stirred for 1.5 h at
room temperature. A saturated aqueous solution of NH4Cl was
added at 0 ꢀC, and the mixture was extracted with ether three times.
The combined extracts were washed with brine, dried (MgSO4), and
evaporated to leave the crude product, which was purified by silica
gel column chromatography using a mixture of hexane and CH2Cl2
as eluent to give (E)-but-1-en-3-ynylbenzene (2.1 g, 16.4 mmol) in
90% yield. To a mixture of NBS (3.52 g, 19.2 mmol) and AgNO3
(272 mg, 1.6 mmol) in acetone (50 mL) was added (E)-but-1-en-3-
ynylbenzene (2.05 g,16 mmol) and the mixture was stirred for 1.5 h
at room temperature and cooled to 0 ꢀC. Water was added and the
mixture was extracted with ether three times. The combined ex-
tracts were washed with brine, dried (MgSO4), and evaporated to
leave the crude product, which was purified by silica gel column
chromatography using hexane as eluent to give 2j (3.1 g,15.0 mmol)
in 94% yield. Spectral data of (E)-trimethyl(4-phenylbut-3-en-1-
ynyl)silane, (E)-but-1-en-3-ynylbenzene, and 2j were identical to
those reported in the literature.17,18
15b: R = C3H7
60%
R
Ph3PAuCl cat
AgBF4 cat
CH2Cl2, rt, 0.5 h
Cl
16a: R = Ph
16b: R = C3H7
75%
70%
Scheme 7. Preparation of chloro-substituted tetracene derivatives.
3. Conclusions
A novel and highly efficient synthetic method of chloro- and
bromo-substituted aromatic compounds has been developed. CuX2
(X¼Cl, Br) acts not only as a Lewis acid for promotion of the
benzannulation but also as a halogenating agent. The present
method allows us to provide various kinds of stereo-defined ha-
logenated aromatic compounds. The synthetic utility of the method
is enhanced by its ability to prepare 2,20-binaphthyl skeletons and
poly-substituted tetracene derivatives.
4. Experimental
4.1. General
NMR spectra were measured at 400 MHz for 1H and 100 MHz for
13C by JEOL JNM-AL 400 spectrometer. Chemical shifts of 1H NMR
were expressed in parts per million downfield from tetramethyl-
silane with reference to internal residual CHCl3
Chemical shifts of 13C NMR were expressed in parts per million
downfield from CDCl3 as an internal standard (
¼77.0) in CDCl3.
(d¼7.26) in CDCl3.
Aldehydes 1a,19 1b,19 and alkyne 2m20 were prepared according
to the literature.
d
GC–MS analysis was performed with an Agilent 6890N GC inter-
faced to an Agilent 5973 mass-selective detector (30 mꢂ0.25 mm
capillary column, HP-5MS). High-resolution mass spectra (HRMS)
were performed on Bruker Daltonics Apex III spectrometer. For thin
layer chromatography (TLC) analysis throughout this work, Merck
precoated TLC plates (Kieselgel 60 F254, 0.2 mm) were used. The
products were purified by flash column chromatography on silica
4.4. General procedure for the synthesis
of 1-halonaphthalenes
To a suspension of CuCl2 (135 mg, 1 mmol) in CH3NO2 (2 mL)
were added 1 (0.5 mmol) and 2 (0.6 mmol) successively at room
temperature under an Ar atmosphere. The mixture was stirred at
80 ꢀC for 4 h and then cooled to room temperature. The resulting
mixture was transferred to a silica gel column, and the product was
isolated using a mixture of hexane and CH2Cl2 as eluent.
gel 60 N (KANTO, 40–50 mm). All manipulations were carried out
under argon atmosphere using standard Schlenk techniques.
4.2. (Z)-3,5-Diphenylpent-2-en-4-ynal (1c)
4.4.1. 1-Chloro-2-phenylnaphthalene (3a). White solid; 1H NMR
To a solution of (Z)-3-bromo-3-phenylacrylaldehyde16 (4.8 g,
23 mmol) in CH3CN (70 mL) and Et3N (18 mL) were added PdCl2
(204 mg, 1.15 mmol), PPh3 (603 mg, 2.3 mmol), CuI (438 mg,
(CDCl3, 400 MHz)
d
8.42 (d, J¼8.5 Hz, 1H), 7.89 (d, J¼8.0 Hz, 1H),
7.82 (d, J¼8.5 Hz, 1H), 7.65–7.44 (m, 8H); 13C NMR (CDCl3, 100 MHz)
d
140.2, 137.8, 133.5, 131.2, 129.7, 129.4, 128.4, 128.00, 127.97, 127.5,

Y. Isogai et al. / Tetrahedron 65 (2009) 9575–9582
9579
127.3,126.7, 126.5, 125.0; IR (KBr) 1491,1443, 1331, 1242,1069, 1024,
970, 866, 818, 748, 700 cmꢁ1; GC–MS (EI) m/z (%) 234 (Mþ, 100);
Anal. Calcd for C16H11Cl: C, 80.50; H, 4.65, found: C, 80.41; H, 4.70;
mp 85 ꢀC.
NMR (CDCl3, 100 MHz)
d
139.5, 139.2, 135.3, 133.6, 130.5, 129.5,
129.1, 128.3, 127.3, 127.2, 126.7, 126.5, 126.3, 124.8, 21.9; IR (neat)
3057, 1489, 1445, 1258, 920, 880, 847, 750 cmꢁ1; GC–MS (EI) m/z (%)
252 (Mþ, 100); Anal. Calcd for C17H13Cl: C, 80.79; H, 5.18, found: C,
80.63; H, 5.38.
4.4.2. 1-Chloro-2-(4-(trifluoromethyl)phenyl)naphthalene
(3b). White solid; 1H NMR (CDCl3, 400 MHz)
d
8.41 (d, J¼8.5 Hz,1H),
4.4.9. 1-Chloro-2,3-dipropylnaphthalene (3h). White solid; 1H NMR
7.91 (d, J¼7.8 Hz, 1H), 7.85 (d, J¼8.3 Hz, 1H), 7.74 (d, J¼8.3 Hz, 2H),
(CDCl3, 400 MHz)
d
8.25 (d, J¼8.5 Hz, 1H), 7.73 (d, J¼7.8 Hz, 1H),
7.69–7.58 (m, 4H), 7.43 (d, J¼8.5 Hz, 1H); 13C NMR (CDCl3, 100 MHz)
7.54 (s, 1H), 7.52–7.42 (m, 2H), 2.98–2.93 (m, 2H), 2.80–2.76 (m,
d
143.7, 136.4, 133.8, 131.1, 130.1, 129.64 (q, J¼33.0 Hz), 129.57, 128.1,
2H), 1.77–1.60 (m, 4H), 1.10–1.03 (m, 6H); 13C NMR (CDCl3,
127.8, 127.6, 127.1, 126.9, 125.03, 124.99, 124.2 (q, J¼270.0 Hz); IR (KBr)
100 MHz) d 139.6, 137.4, 132.7, 131.1, 129.9, 127.3, 126.2, 126.0,
1655, 1614, 1560, 1499, 1406, 1327, 1167, 1123, 1082, 1063, 816 cmꢁ1
;
125.6, 124.3, 35.9, 32.7, 24.3, 23.0, 14.6, 14.2; IR (KBr) 2960, 1489,
1450, 1251, 935, 894, 748 cmꢁ1; GC–MS (EI) m/z (%) 246 (Mþ, 100);
Anal. Calcd for C16H19Cl: C, 77.87; H, 7.76, found: C, 77.88; H, 7.74;
mp 32–33 ꢀC.
GC–MS (EI) m/z (%) 306 (Mþ,100); Anal. Calcd for C17H10ClF3: C, 66.57;
H, 3.29, found: C, 66.58; H, 3.46; mp 121–122 ꢀC.
4.4.3. 1-Chloro-2-(4-methoxyphenyl)naphthalene (3c). White solid;
1H NMR (CDCl3, 400 MHz)
d
8.40 (d, J¼8.5 Hz, 1H), 7.88 (d,
4.4.10. 1-Chloro-2-cyclohexenylnaphthalene (3i). White solid; 1H
J¼9.3 Hz, 1H), 7.80 (d, J¼8.3 Hz, 1H), 7.63 (dd, J¼8.0, 8.0 Hz, 1H),
NMR (CDCl3, 400 MHz)
d
8.33 (d, J¼7.8 Hz, 1H), 7.82 (d, J¼8.0 Hz,
7.55 (dd, J¼7.6, 7.6 Hz, 1H), 7.46–7.44 (m, 3H), 7.01 (d, J¼2.4 Hz, 2H),
1H), 7.71 (d, J¼8.3 Hz, 1H), 7.58 (tt, J¼1.5, 8.3 Hz, 1H), 7.49 (tt, J¼1.2,
7.1 Hz, 1H), 7.29 (d, J¼8.5 Hz, 1H), 5.74 (sept, J¼1.9 Hz, 1H), 2.37 (m,
2H), 2.44 (m, 2H), 1.83 (m, 2H), 1.74 (m, 2H); 13C NMR (CDCl3,
3.89 (t, J¼2.4 Hz, 3H); 13C NMR (CDCl3, 100 MHz)
d 159.0, 137.4,
133.4, 132.5, 131.2, 130.9, 129.4, 128.6, 127.9, 127.3, 126.7, 126.3,
124.9, 113.5, 55.3; IR (KBr) 1607, 1514, 1495, 1460, 1439, 1286, 1252,
1177, 1024, 972, 821 cmꢁ1; GC–MS (EI) m/z (%) 268 (Mþ, 100); Anal.
Calcd for C17H13ClO: C, 75.98; H, 4.88. Found: C, 75.99; H, 5.13; mp
103–104 ꢀC.
100 MHz)
d 140.7, 138.1, 133.2, 131.1, 128.9, 127.83, 127.75, 127.4,
126.9, 126.5, 125.9, 124.6, 29.3, 25.5, 23.0, 22.1; IR (KBr) 1497, 1435,
1325, 978, 918, 860, 810, 772 cmꢁ1; GC–MS (EI) m/z (%) 242 (Mþ,
92), 179 (100); Anal. Calcd for C16H15Cl: C, 79.17; H, 6.23, found: C,
78.95; H, 7.74; mp 49–50 ꢀC.
4.4.4. 2-Butyl-1-chloronaphthalene (3d). Colorless oil; 1H NMR
(CDCl3, 400 MHz)
d
8.31 (d, J¼8.3 Hz, 1H), 7.81 (d, J¼8.0 Hz, 1H),
4.4.11. 3-Bromo-1-chloro-2-styrylnaphthalene (3j). White crystal;
7.69 (d, J¼8.3 Hz, 1H), 7.57 (tt, J¼1.5, 8.0 Hz, 1H), 7.48 (tt, J¼1.2,
8.0 Hz, 1H), 7.34 (d, J¼8.5 Hz, 1H), 2.95 (t, J¼7.8 Hz, 2H), 1.69 (quint,
J¼7.8 Hz, 2H), 1.44 (sext, J¼7.3 Hz, 2H), 0.97 (t, J¼7.3 Hz, 3H); 13C
1H NMR (CDCl3, 400 MHz)
d
8.31 (d, J¼8.0 Hz, 1H), 8.11 (s, 1H), 7.75
(d, J¼8.0 Hz, 1H), 7.64–7.52 (m, 4H), 7.42 (t, J¼7.2 Hz, 2H), 7.33 (t,
J¼7.2 Hz, 1H), 7.28–7.24 (m, 1H), 7.08 (d, J¼16 Hz, 1H); 13C NMR
NMR (CDCl3,100 MHz)
d
137.8,133.0,131.2,130.1,128.0,127.8,126.8,
(CDCl3, 100 MHz) d 137.2, 136.6, 133.7, 133.5, 131.2, 130.5, 130.3,
126.5, 125.6, 124.3, 34.2, 32.2, 22.7, 14.1; IR (neat) 3053, 2957, 2930,
128.7, 128.2, 127.5, 127.3, 127.0, 126.7, 125.5, 125.2, 121.3; IR (KBr)
2862, 1560, 1504, 1466, 1377, 1354, 1339, 1259, 1225, 988, 812 cmꢁ1
;
1767, 1553, 1487, 1450, 1250, 1184, 964, 847, 779, 764, 737 cmꢁ1
;
GC–MS (EI) m/z (%) 218 (Mþ, 43),175 (100); Anal. Calcd for C14H15Cl:
GC–MS (EI) m/z (%) 344 (Mþ, 18), 228 (100); Anal. Calcd for
C18H12BrCl: C, 62.91; H, 3.52, found: C, 62.60; H, 3.84; mp 108–
109 ꢀC.
C, 76.88; H, 6.91, found: C, 76.86; H, 7.08.
4.4.5. 2-tert-Butyl-1-chloronaphthalene (3e). Colorless oil; 1H NMR
(CDCl3, 400 MHz)
d
8.45 (d, J¼8.5 Hz, 1H), 7.80 (d, J¼8.0 Hz, 1H),
4.4.12. 1-Bromo-2-phenylnaphthalene (4a). Colorless oil; 1H NMR
7.40 (d, J¼8.8 Hz, 1H), 7.63 (d, J¼9.0 Hz, 1H), 7.57 (tt, J¼1.5, 8.5 Hz,
(CDCl3, 400 MHz)
(tt, J¼8.0, 1.2 Hz, 1H), 7.57 (tt, J¼6.8, 1.2 Hz, 1H), 7.54–7.42 (m, 6H);
13C NMR (CDCl3, 100 MHz)
142.2, 140.7, 133.5, 132.4, 129.6, 128.4,
d
8.42 (d, J¼7.8 Hz, 1H), 7.87–7.66 (m, 2H), 7.65
1H), 7.49 (tt, J¼1.2, 8.0 Hz, 1H), 1.62 (s, 9H); 13C NMR (CDCl3,
100 MHz)
d
143.7, 132.9, 132.2, 130.7, 127.5, 126.8, 126.5, 125.8,
d
125.3, 124.6, 36.7, 30.2; IR (neat) 2961, 2924, 1483, 1364, 1335, 1240,
976, 812 cmꢁ1; GC–MS (EI) m/z (%) 218 (Mþ, 59), 218 (100); HRMS
(EI) calcd for C14H15Cl (Mþ) 218.0862, found 218.0862.
128.0, 127.91, 127.88, 127.6, 127.5, 127.4, 126.5, 122.5; IR (neat) 1491,
1441, 1323, 1240, 1024, 955, 864, 816, 758 cmꢁ1; GC–MS (EI) m/z (%)
282 (Mþ, 100); HRMS (EI) calcd for C16H11Br (Mþ) 282.0044, found
282.0040.
4.4.6. (4-Chloronaphthalen-2-yl)trimethylsilane (3f). Colorless oil;
1H NMR (CDCl3, 400 MHz)
d
8.35 (d, J¼8.3 Hz, 1H), 7.83 (d, J¼7.8 Hz,
4.4.13. 1-Bromo-2-butylnaphthalene (4b). Colorless oil; 1H NMR
1H), 7.74 (d, J¼8.3 Hz, 1H), 7.50–7.61 (m, 3H), 0.46 (s, 9H); 13C NMR
(CDCl3, 400 MHz)
d
8.32 (d, J¼8.5 Hz, 1H), 7.79 (d, J¼8.0 Hz, 1H),
(CDCl3, 100 MHz)
d
139.3, 135.9, 135.0, 130.9, 130.7, 127.9, 126.9,
7.72 (d, J¼8.5 Hz, 1H), 7.58 (tt, J¼1.2, 6.8 Hz, 1H), 7.47 (tt, J¼1.2,
8.0 Hz, 1H), 7.34 (d, J¼4.1 Hz, 1H), 2.99 (t, J¼7.8 Hz, 2H), 1.69 (quint,
J¼5.9 Hz, 2H), 1.51 (sext, J¼7.3 Hz, 2H), 0.98 (t, J¼7.3 Hz, 3H); 13C
126.8, 126.0, 124.4, ꢁ0.4; IR (neat) 2953, 1304, 1247, 973, 866, 835,
810 cmꢁ1; MS (EI) m/z (%) 234 (Mþ, 18), 183 (100); HRMS (EI) calcd
for C13H15ClSi (Mþ) 234.0632, found 234.0631.
NMR (CDCl3,100 MHz) d 140.3,133.0,132.6,128.1,127.9,127.3,127.2,
127.1, 125.6, 123.5, 37.2, 32.4, 22.7, 14.1; IR (neat) 3057, 1488, 1445,
1352, 1258, 920, 880, 847, 775 cmꢁ1; GC–MS (EI) m/z (%) 262 (Mþ,
58), 219 (100); Anal. Calcd for C14H15Br: C, 63.89; H, 5.74, found: C,
63.84, H, 5.74.
4.4.7. (1-Chloronaphthalen-2-yl)trimethylsilane (3f0). Colorless oil;
1H NMR (CDCl3, 400 MHz)
d
8.25 (d, J¼8.3 Hz, 1H), 7.90 (s, 1H), 7.86
(d, J¼8.1 Hz, 1H), 7.65 (s, 1H), 7.60 (dd, J¼6.8, 7.1 Hz, 1H), 7.54 (ddd,
J¼1.0, 6.8, 7.8 Hz, 1H), 0.36 (s, 9H); 13C NMR (CDCl3, 100 MHz)
d
138.7, 134.2, 132.7, 131.5, 130.8, 129.8, 128.2, 127.3, 126.6, 124.2,
4.5. 1-Chloro-2,6-diphenylbenzene (11)
ꢁ1.09; IR (neat) 2954, 1249, 1096, 974, 819, 746 cmꢁ1; MS (EI) m/z
(%) 234 (Mþ, 26), 219 (100); HRMS (EI) calcd for C13H15ClSi (Mþ)
234.0632, found 234.0630.
To a suspension of CuCl2 (135 mg, 1 mmol) in CH3NO2 (2 mL)
were added 1c (116 mg, 0.5 mmol) and 2a (0.07 mL, 0.6 mmol)
successively at room temperature under an Ar atmosphere. The
mixture was stirred at 60 ꢀC for 2 h and then cooled to room
temperature. The resulting mixture was transferred to a silica gel
column, and the product was isolated using hexane as eluent; 10
4.4.8. 1-Chloro-3-methyl-2-phenylnaphthalene (3g). Colorless oil;
1H NMR (CDCl3, 400 MHz)
d
8.29 (d, J¼7.6 Hz, 1H), 7.81 (d, J¼7.3 Hz,
1H), 7.79 (s, 1H), 7.67–7.41 (m, 5H), 7.25 (m, 2H), 2.20 (s, 3H); 13C

9580
Y. Isogai et al. / Tetrahedron 65 (2009) 9575–9582
was obtained as a white solid (66 mg, 0.25 mmol) in 50% yield. 1H
(Mþ, 100); HRMS (ESI) calcd for C16H16ONa ([MþNa])þ 247.1093,
NMR (CDCl3, 400 MHz)
NMR (CDCl3, 100 MHz)
d
7.49–7.43 (m, 8H), 7.43–7.32 (m, 5H); 13
141.5, 140.0, 130.9, 130.3, 129.5, 127.9,
C
found 247.1092; mp 70.5 ꢀC.
d
127.4, 126.3; IR (KBr) 3055, 1495, 1456, 1439, 1398, 1049, 1030, 802,
762, 700 cmꢁ1; MS (EI) m/z (%) 264 (Mþ 100); Anal. Calcd for
C18H13Cl: C, 81.66; H, 4.95, found: C, 81.65; H, 5.02; mp 90 ꢀC.
4.7.2. Preparation of 13. To a solution of (COCl)2 (2.3 mL,
26.8 mmol) in CH2Cl2 (40 mL) was added dropwise a solution of
DMSO (2.8 mL, 39.4 mmol) in CH2Cl2 (8 mL) at ꢁ78 ꢀC over 10 min.
After the mixture was stirred for 15 min at ꢁ78 ꢀC, a solution of (3-
(pent-1-ynyl)naphthalen-2-yl)methanol (2.8 g, 12.5 mmol) in
CH2Cl2 (15 mL) was added dropwise over 10 min and the reaction
temperature rised to ꢁ45 ꢀC. After the mixture was stirred for 1 h at
ꢁ45 ꢀC, Et3N (12.3 mL, 88 mmol) was added. The mixture was
allowed to warm to 0 ꢀC and it was stirred for 20 min. A saturated
aqueous solution of NH4Cl was added, and the mixture was
extracted with ether three times. The combined extracts were
washed with brine, dried (MgSO4), and evaporated to leave the
crude product, which was purified by silica gel column chroma-
tography using a mixture of hexane and AcOEt as eluent to give 13
(2.0 g, 9.2 mmol) in 73% yield as a yellow oil; 1H NMR (CDCl3,
4.6. General procedure for the synthesis of 2,20-binaphthyls
To a suspension of CuX2 (1 mmol) in (CH2Cl)2 (2 mL) were added
1a (0.5 mmol) and 2 (0.2 mmol) successively at room temperature
under an Ar atmosphere. The mixture was stirred at 100 ꢀC for 1.5 h
and then cooled to room temperature. The resulting mixture was
transferred to a silica gel column, and the product was isolated
using a mixture of hexane and CH2Cl2 as eluent.
4.6.1. 3,30-Dibutyl-1,10-dichloro-2,20-binaphthyl (12a). White solid;
1H NMR (CDCl3, 400 MHz)
d
8.32 (dd, J¼4.8, 4.8 Hz, 1H), 7.87 (dd,
400 MHz)
d
10.68 (s, 1H), 8.43 (s, 1H), 8.00 (s, 1H), 7.95 (d, J¼8.1 Hz,
J¼4.8, 4.8 Hz, 1H), 7.76 (s, 1H), 7.59–7.56 (m, 2H), 2.37 (t, J¼7.5 Hz,
1H), 7.81 (d, J¼8.3 Hz, 1H), 7.59 (dd, J¼6.8, 8.1 Hz, 1H), 7.53 (dd,
2H), 1.56–1.52 (m, 2H), 1.21 (sext, J¼7.3 Hz, 2H), 0.78 (t, J¼7.3 Hz,
J¼7.1, 7.8 Hz, 1H), 2.52 (t, J¼6.8 Hz, 2H), 1.71 (dt, J¼7.1, 21.5 Hz, 2H),
3H); 13C NMR (CDCl3, 100 MHz)
d 139.5, 136.0, 133.9, 131.1, 129.5,
1.12 (t, J¼7.3 Hz, 3H); 13C NMR (CDCl3, 100 MHz)
d 192.3, 135.5,
127.6, 126.7, 126.3, 125.8, 124.8, 33.4, 31.4, 22.5, 13.9; IR (KBr) 2957,
2870, 1487, 1464, 1319, 1259, 878, 849, 748 cmꢁ1; GC–MS (EI) m/z
(%) 434 (Mþ, 100); Anal. Calcd for C28H28Cl2: C, 77.23; H, 6.48,
found: C, 77.32; H, 6.43; mp 101–103 ꢀC.
133.1, 132.4, 131.5, 129.9, 129.2, 129.1, 127.3, 127.2, 122.1, 96.9, 76.9,
22.2, 21.7, 13.8; IR (neat) 2962, 2228, 1693, 1620, 1494, 1397, 1247,
1041, 810, 636 cmꢁ1; GC–MS (EI) m/z 222 (Mþ, 17),165 (100); HRMS
(ESI) calcd for C16H14ONa ([MþNa]þ) 245.0937, found 245.0935.
4.6.2. 1,10-Dichloro-3,30-diphenyl-2,20-binaphthyl (12b). White solid;
4.8. 1-Chloro-2-cyclohexenyl-3-iodoanthracene (14)
1H NMR (CDCl3, 400 MHz)
d
8.43 (d, J¼8.3 Hz, 1H), 7.82 (d, J¼7.5 Hz,
1H), 7.65 (m, 2H), 7.57 (tt, J¼1.2, 7.6 Hz, 1H), 7.08 (dd, J¼7.6, 7.6 Hz,
To a suspension of CuCl2 (270 mg, 2 mmol) in (CH2Cl)2 (1 mL)
were added a solution of 13 (222 mg, 1.0 mmol) in (CH2Cl)2 (1.5 mL)
and a solution of 1-(iodoethynyl)cyclohex-1-ene 2m (464 mg,
2.0 mmol) in (CH2Cl)2 (1.5 mL) successively at room temperature.
The mixture was stirred at 40 ꢀC for 1 h and then cooled to room
temperature. A saturated aqueous solution of NH4Cl was added,
and the mixture was extracted with ether three times. The com-
bined extracts were washed with brine, dried (MgSO4), and evap-
orated to leave the crude product, which was purified by silica gel
column chromatography using a mixture of hexane and CH2Cl2 as
eluent to give 14 (217 mg, 0.52 mmol) in 52% yield as a yellow solid;
1H), 6.98 (dd, J¼7.6, 7.6 Hz, 2H), 6.71 (d, J¼8.0 Hz, 2H); 13C NMR
(CDCl3, 100 MHz)
d 140.0, 139.9, 134.8, 133.6, 133.3, 129.8, 129.2,
128.2, 128.0, 127.2, 127.1, 127.0, 126.7, 125.0; IR (KBr) 1591, 1556, 1485,
1447, 1325, 1265, 976, 918, 893, 849, 750 cmꢁ1; GC–MS (EI) m/z (%)
474 (Mþ, 100); Anal. Calcd for C32H20Cl2: C, 80.84; H, 4.24, found: C,
81.62; H, 4.41; mp 206–208 ꢀC.
4.6.3. 1,10-Dibromo-3,30-diphenyl-2,20-binaphthyl (12c). White solid;
1H NMR (CDCl3, 400 MHz)
d
8.44 (d, J¼8.7 Hz, 1H), 7.80 (d, J¼8.1 Hz,
1H), 7.64 (m, 2H), 7.56 (tt, J¼1.2, 7.4 Hz, 1H), 7.08 (dd, J¼7.4, 7.4 Hz,
1H), 6.98 (dd, J¼7.6, 7.6 Hz, 2H), 6.74 (d, J¼8.0 Hz, 2H); 13C NMR
1H NMR (CDCl3, 400 MHz)
d 8.81 (s, 1H), 8.52 (s, 1H), 8.24 (s, 1H),
(CDCl3, 100 MHz)
d 140.0, 139.9, 139.2, 133.6, 131.2, 129.4, 129.0,
8.02–8.08 (m, 1H), 7.95–8.01 (m, 1H), 7.47–7.55 (m, 2H), 6.66 (dd,
128.2, 127.9, 127.5, 127.4, 127.2, 127.0, 126.8; IR (KBr) 1653, 1576,
1553, 1522, 1508, 1481,þ1458, 1321, 1250, 893, 750 cmꢁ1; HRMS (EI)
calcd for C32H20Br2 (M ) 561.9932, found 561.9930; mp 229 ꢀC.
J¼2.0, 3.7 Hz, 1H), 2.22–2.38 (m, 4H), 1.89–1.96 (m, 2H), 1.75–1.84
(m, 2H); 13C NMR (CDCl3, 100 MHz)
d 141.51, 141.49, 140.8, 137.3,
132.3, 132.2, 131.8, 128.6, 128.54, 128.51, 127.8, 126.3, 126.2, 125.4,
124.1, 97.2, 28.4, 25.3, 22.8, 21.9; IR (neat) 3854, 2928, 1603, 1445,
1122, 916, 872, 781, 710 cmꢁ1; GC–MS (EI) m/z 418 (Mþ, 100); HRMS
(EI) calcd for C20H16ClI (Mþ) 417.9985, found 417.9982; mp 125.5 ꢀC.
4.7. 3-(Phenylethynyl)-2-naphthaldehyde (13)
4.7.1. Preparation of (3-(pent-1-ynyl)naphthalen-2-yl)methanol. To
a solution of (3-iodonaphthalen-2-yl)methanol21 (5.2 g, 18.4 mmol)
in Et3N (40 mL) were added PdCl2 (65.3 mg, 0.37 mmol), PPh3
(193 mg, 0.74 mmol), CuI (294 mg, 1.54 mmol), and pentyne
(2.17 mL, 22 mmol) successively at room temperature and the
mixture was stirred for 3 h at 60 ꢀC. A saturated aqueous solution of
NH4Cl was added, and the mixture was extracted with ether three
times. The combined extracts were washed with brine, dried
(MgSO4), and evaporated to leave the crude product, which was
purified by silica gel column chromatography using a mixture of
hexane and AcOEt as eluent to give (3-(pent-1-ynyl)naphthalen-2-
yl)methanol (3.67 g, 16.4 mmol) in 89% yield as a yellow solid; 1H
4.9. General procedure for the synthesis of anthracene
derivatives
To a solution of 14 (418 mg, 1.0 mmol) in THF (5 mL) and Et3N
(0.5 mL) were added PdCl2 (3.5 mg, 0.02 mmol), PPh3 (10.5 mg,
0.04 mmol), CuI (15.2 mg, 0.08 mmol), and alkyne (2 mmol) suc-
cessively at room temperature and the mixture was stirred for 4 h
at 60 ꢀC. A saturated aqueous solution of NH4Cl was added, and the
mixture was extracted with ether three times. The combined ex-
tracts were washed with brine, dried (MgSO4), and evaporated to
leave the crude product, which was purified by silica gel column
chromatography using a mixture of hexane and CH2Cl2 as eluent to
give 15.
NMR (CDCl3, 400 MHz) d 7.93 (s, 1H), 7.81 (s, 1H), 7.74–7.80 (m, 2H),
7.43–7.49 (m, 2H), 4.95 (d, J¼6.1 Hz, 2H), 2.44–2.53 (m, 3H), 1.69
(ddd, J¼7.3, 14.4, 14.4 Hz, 2H), 1.11 (t, J¼7.3 Hz, 3H); 13C NMR (CDCl3,
100 MHz)
d
138.8, 132.5, 132.3, 132.0, 127.7, 127.2, 126.5, 126.2,
4.9.1. 1-Chloro-2-cyclohexenyl-3-(phenylethynyl)anthracene
125.6, 119.9, 94.9, 78.5, 64.4, 22.3, 21.6, 13.7; IR (neat) 3304, 2927,
(15a). Yellow crystal; 1H NMR (CDCl3, 400 MHz)
d
8.84 (s, 1H), 8.37
1600, 1492, 1341, 1108, 1035, 876, 742 cmꢁ1; GC–MS (EI) m/z 224
(s, 1H), 8.17 (s, 1H), 8.03–8.10 (m, 1H), 7.96–8.02 (m, 1H), 7.47–7.59

Y. Isogai et al. / Tetrahedron 65 (2009) 9575–9582
9581
(m, 4H), 7.33–7.42 (m, 3H), 5.80 (dd, J¼1.7, 3.4 Hz, 1H), 2.37–2.48
package except for refinement, which was performed using
SHELXL-97.22,23
(m, 2H), 2.26–2.36 (m, 2H), 1.76–1.97 (m, 4H); 13C NMR (CDCl3,
100 MHz) d 140.3, 136.4, 132.6, 131.9, 131.5, 131.2, 130.5, 129.4, 128.7,
128.7, 128.4, 128.3, 127.9, 127.6, 126.5, 126.19, 126.16, 123.9, 123.4,
121.1, 92.5, 88.9, 28.7, 25.6, 23.2, 22.3; IR (neat) 2360, 2341, 1739,
1365, 1217, 904, 882, 739, 687 cmꢁ1; Anal. Calcd for C28H21Cl: C,
85.59; H, 5.39; Cl, 9.02; found C, 85.54; H, 5.50; Cl, 9.11; mp
145.5 ꢀC.
4.11.2. Crystal data of 3,30-Dibutyl-1,10-dichloro-2,20-binaphthyl
(12a). C28H28Cl2, Mw¼435.43, colorless prism, 0.20ꢂ0.20
ꢂ0.20 mm, triclinic, space group P-1 (no. 2), a¼8.156(6) Å,
b¼9.859(7) Å, c¼14.837(11) Å,
a
¼96.633(13)ꢀ,
b
¼100.974(14)ꢀ,
g
¼98.632(14)ꢀ, V¼1145.0(14) Å3, T¼173 K, Z¼2,
m
(Mo K
a
)¼2.957
cmꢁ1,16,635reflectionsmeasured,5187unique(Rint¼0.017). Thefinal
4.9.2. 1-Chloro-2-cyclohexenyl-3-(pent-1-ynyl)anthracene
R1 and wR2 were 0.0461 (I>2.00s(I)) and 0.1316 (for all data), re-
(15b). Yellow solid; 1H NMR (CDCl3, 400 MHz)
d
8.82 (s,1H), 8.31 (s,
spectively. Crystallographic data (excluding structure factors) for the
structure of 12a have been deposited with the Cambridge Crystallo-
graphic Data Center as supplementary publication no. CCDC 727312.
Copies of the data can be obtained, free of charge, on application to
CCDC, 12 Union Road, Cambridge CB2 1EZ, UK (fax: t44 (0)1223
336033 or e-mail:deposit@ccdc.cam.ac.uk).
1H), 8.03–8.05 (m,1H), 8.02 (s,1H), 7.94–8.00 (m,1H), 7.46–7.53 (m,
2H), 5.71 (dt, J¼1.9, 3.7 Hz, 1H), 2.46 (t, J¼7.1 Hz, 2H), 2.31–2.38 (m,
2H), 2.23–2.30 (m, 2H), 1.73–1.92 (m, 4H), 1.67 (dt, J¼7.3, 14.4 Hz,
2H), 1.09 (t, J¼7.3 Hz, 3H); 13C NMR (CDCl3, 100 MHz)
d 140.7, 136.6,
132.4, 131.8, 130.8, 130.6, 129.2, 128.6, 128.5, 127.8, 127.2, 126.1,
126.0, 125.9, 123.8, 121.9, 93.5, 79.9, 28.6, 25.5, 23.1, 22.4, 22.2, 21.8,
13.7; IR (neat) 2921, 2361, 1738, 1365, 1217, 895, 881, 797, 736, 676,
631 cmꢁ1; GC–MS (EI) m/z 358 (Mþ, 61), 265 (100); HRMS (EI) calcd
for C25H23Cl (Mþ) 358.1488, found 358.1485; mp 131.5 ꢀC.
References and notes
1. For reviews, see: (a) de Meijere, A.; Diederich, F. Metal-Catalyzed Cross-Coupling
Reactions; Wiley-VCH GmbH & KGaA: Weinheim, Germany, 2004; (b) Stu¨rmer,
R. Angew. Chem. 1999, 111, 3509–3510; Angew. Chem., Int. Ed. 1999, 38, 3307–
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4.10. General procedure for the synthesis of tetracene
derivatives
To a mixture of Ph3PAuCl (4.5 mg, 0.009 mmol) and AgBF4
(2.1 mg, 0.01 mmol) in CH2Cl2 (1 mL) was added a solution of 15
(0.18 mmol) in CH2Cl2 at room temperature and the mixture was
stirred for 30 min at the same temperature. A saturated aqueous
solution of NH4Cl was added, and the mixture was extracted with
CH2Cl2 three times. The combined extracts were washed with
brine, dried (MgSO4), and evaporated to leave the crude product,
which was purified by silica gel column chromatography using
a mixture of hexane and CH2Cl2 as eluent to give 16.
´
850–888; Angew. Chem., Int. Ed. 2007, 46, 834–871; (g) Chinchilla, R.; Najera, C.
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4.10.1. 14-Chloro-5-phenyl-1,2,3,4-tetrahydrobenzo[a]tetracene
(16a). Red solid; 1H NMR (CDCl3, 400 MHz)
d 9.21 (s, 1H), 8.58 (s,
1H), 8.46 (s, 1H), 8.08 (dd, J¼3.3, 5.5 Hz, 1H), 7.98 (dd, J¼3.3, 5.5 Hz,
1H), 7.61 (s, 1H), 7.35–7.50 (m, 7H), 3.73–3.82 (m, 2H), 2.65–2.72
(m, 2H), 1.76–1.88 (m, 4H); 13C NMR (CDCl3, 100 MHz)
d141.4, 140.6,
´
Tetrahedron 2006, 62, 11483–11498; (h) Barluenga, J.; Alvarez-Gutie´rrez, J. M.;
135.3,133.0,132.2,131.6,131.3,129.7,129.4,129.1,129.1,129.0,128.0,
127.6, 127.4, 127.1, 127.0, 126.9, 126.1, 125.7, 125.5, 124.3, 33.0, 30.9,
23.7, 22.5; IR (neat) 2358, 2339, 1737, 1364, 1217, 904, 873, 732, 702,
627, 609 cmꢁ1; HRMS (EI) calcd for C28H21Cl (Mþ) 392.1332, found
392.1330; mp 223 ꢀC.
Ballesteros, A.; Gonza´lez, J. M. Angew. Chem. 2007, 119, 1303–1305; Angew.
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4.10.2. 14-Chloro-5-propyl-1,2,3,4-tetrahydrobenzo[a]tetracene
(16b). Red crystal; 1H NMR (CDCl3, 400 MHz)
d 9.22 (s, 1H), 8.55 (s,
8. (a) Asao, N. Synlett 2006, 1645–1656; (b) Asao, N.; Sato, K. J. Synth. Org. Chem.
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1H), 8.42 (s, 1H), 8.03–8.10 (m, 1H), 7.94–8.00 (m, 1H), 7.53 (s, 1H),
7.38–7.45 (m, 2H), 3.74 (t, J¼6.3 Hz, 2H), 2.89 (t, J¼6.3 Hz, 2H), 2.68
(t, J¼7.3 Hz, 2H), 1.90–1.98 (m, 2H), 1.68–1.84 (m, 4H), 1.08 (t,
J¼7.3 Hz, 3H); 13C NMR (CDCl3, 150 MHz)
d
139.0, 136.3, 132.7, 132.2,
´
´
9. (a) Barluenga, J.; Vazquez-Villa, H.; Ballesteros, A.; Gonzalez, J. M. Org. Lett. 2003,
´
5, 4121–4123; (b) Yue, D.; Ca, N. D.; Larock, R. C. Org. Lett. 2004, 6, 1581–1584; (c)
132.0, 131.3, 129.7, 129.2, 129.1, 129.0, 127.7, 126.9, 125.9, 125.8,
125.6, 125.4, 125.3, 124.2, 35.0, 33.1, 28.3, 23.6, 23.0, 22.6, 14.3; IR
(neat) 3734, 2943, 2361, 2341, 1734, 1540, 1458, 1362, 1265, 1116,
901, 884, 867, 830, 819, 729, 671 cmꢁ1; Anal. Calcd for C25H23Cl: C,
83.66; H, 6.46; Cl, 9.88, found C, 83.59; H, 6.41; Cl, 9.40; mp 136 ꢀC.
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´
´
Vazquez-Villa, H.; Merino, I.; Ballesteros, A.; Gonzalez, J. M. Chem.dEur. J. 2006,
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4.11.1. X-ray crystallographic analysis of 12a. X-ray data of 12a were
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´
Murphy, A. R.; Frechet, J. M. J. Chem. Rev. 2007, 107, 1066–1096; (d) Anthony,
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a radiation (l 0.71070 Å). The data were
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