Synthesis of unsymmetrical divinylbenzenes by palladium catalyzed sequential heck reactions starting from carboxybenzenediazonium salts

Article abstract of DOI:10.1081/SCC-120016321

Six p-, m- and o-unsymmetrical divinylbenzenes 5a, 5b, 6a, 6b, 6c and 7a are synthesized from p-, m- and o- carboxybenzenediazonium tetrafluoroborates via sequential Heck reactions in good overall yield.

Full text of DOI:10.1081/SCC-120016321

This article was downloaded by: [Northeastern University]
On: 18 November 2014, At: 16:17
Publisher: Taylor & Francis
Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House,
37-41 Mortimer Street, London W1T 3JH, UK
Synthetic Communications: An International Journal
for Rapid Communication of Synthetic Organic
Chemistry
Publication details, including instructions for authors and subscription information:
http://www.tandfonline.com/loi/lsyc20
Synthesis of Unsymmetrical Divinylbenzenes by
Palladium Catalyzed Sequential Heck Reactions Starting
from Carboxybenzenediazonium Salts
Chao Wang a , Lu-Shi Tan a , Jin-Ping He a , Hong-Wen Hu a & Jian-Hua Xu a
a Department of Chemistry , Nanjing University , Nanjing, China
Published online: 17 Aug 2006.
To cite this article: Chao Wang , Lu-Shi Tan , Jin-Ping He , Hong-Wen Hu & Jian-Hua Xu (2003) Synthesis of Unsymmetrical
Divinylbenzenes by Palladium Catalyzed Sequential Heck Reactions Starting from Carboxybenzenediazonium Salts, Synthetic
Communications: An International Journal for Rapid Communication of Synthetic Organic Chemistry, 33:5, 773-782, DOI:
10.1081/SCC-120016321
To link to this article: http://dx.doi.org/10.1081/SCC-120016321
PLEASE SCROLL DOWN FOR ARTICLE
Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained
in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no
representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the
Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and
are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and
should be independently verified with primary sources of information. Taylor and Francis shall not be liable for
any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever
or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of
the Content.
This article may be used for research, teaching, and private study purposes. Any substantial or systematic
reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any
form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://
www.tandfonline.com/page/terms-and-conditions

MARCEL DEKKER, INC. • 270 MADISON AVENUE • NEW YORK, NY 10016
©2003 Marcel Dekker, Inc. All rights reserved. This material may not be used or reproduced in any form without the express written permission of Marcel Dekker, Inc.
SYNTHETIC COMMUNICATIONSÕ
Vol. 33, No. 5, pp. 773–782, 2003
Synthesis of Unsymmetrical Divinylbenzenes by
Palladium Catalyzed Sequential Heck Reactions
Starting from Carboxybenzenediazonium Salts
Chao Wang,Lu-Shi Tan,Jin-Ping He,Hong-Wen Hu,
*
and Jian-Hua Xu
Department of Chemistry, Nanjing University,
Nanjing, China
ABSTRACT
Six p-, m- and o-unsymmetrical divinylbenzenes 5a, 5b, 6a, 6b, 6c and
7a are synthesized from p-, m- and o- carboxybenzenediazonium
tetrafluoroborates via sequential Heck reactions in good overall yield.
Key Words: Divinylbenzenes; Arenediazoniumsalt; Heck reaction.
*Correspondence: Jian-Hua Xu, Department of Chemistry, Nanjing University,
Nanjing 210093, China; E-mail: xujh@nju.edu.cn.
773
DOI: 10.1081/SCC-120016321
Copyright & 2003 by Marcel Dekker, Inc.
0039-7911 (Print); 1532-2432 (Online)
www.dekker.com

MARCEL DEKKER, INC. • 270 MADISON AVENUE • NEW YORK, NY 10016
©2003 Marcel Dekker, Inc. All rights reserved. This material may not be used or reproduced in any form without the express written permission of Marcel Dekker, Inc.
774
Wang et al.
Palladiumcatalyzed arylation reactions of olefins (the Heck
reaction[1]) conventionally use aryl halides (mainly iodides and bromides)
as arylating reagents and require the addition of a base and a ligand
(usually monodentate phosphines) in the reaction mixture. The use of
other arylation reagents such as arenesulfonyl chlorides,[2] aryl triflates,[3]
aryl perfluoroalkanesulfonates,[4] aroyl chlorides[5] and arenediazonium
salts[6–9] have also been reported. Of all these alternative arylating
reagents, arenediazoniumsalts and aroyl chlorides are more attractive
considering (1) the easy availability of the aryl substrates with diversified
substitution pattern, (2) the high reactivity and (3) that the arenediazo-
nium salts are cheaper than the aryl bromides and iodides (as a matter of
fact, the later are often prepared fromthe corresponding arenediazonium
salts).
Although the Heck reaction has mainly been employed in the synthe-
sis of 1-arylolefins, there is also a potentiality to use it for the synthesis of
unsymmetrical divinylbenzenes which are important synthetic targets in
view of their relation with poly( p-phenylenevinylenes) and nonlinear
optical materials. Heck originally explored this possibility with bromoio-
dobenzenes.[10] Since then, the choice of arylating reagents applicable to
the synthesis of unsymmetrical divinylbenzenes has been largely
expanded. The significant difference in the reactivity of different leaving
groups (Brꢀ, Iꢀ, SO2Clꢀ, OHꢀ, ROSO2ꢀ, COClꢀ, N2, etc.), in participat-
ing the rate determining oxidative addition with palladium(0) can be
made use of to achieve sequential Heck reactions at the same aromatic
substrate to introduce two different vinyl groups. However, these
potentialities have not been widely explored. Spencer explored the use
of bromoaroyl chloride,[11] albeit in limited scope, partly because of the
difficulties in obtaining the regioisomeric halogenoarenes. Very recently,
Sengupta reported the application of iodoarenediazoniumsalt for the
synthesis of para- and ortho-divinylbenzenes.[12] Considering the easy
availability and the low cost of the arylating reagent, as well as the
convenience and versatility of the method, we envision that the arene-
diazoniumsalt-aroyl chloride combination as in 1 (Sch. 1) is an advanta-
geous choice of arylating reagents for these sequential Heck reactions.
Reported here is the synthesis of divinylbenzenes starting fromthe
corresponding carboxybenzenediazoniumsalts via sequential arylation
reactions.
Arylation of acrylic acid and its esters by Heck reaction for the
preparation of cinnamic acid and its esters is of important synthetic
value and has been extensively investigated with aryl iodides[13] and
bromides[14] under various conditions. The use of aroyl chlorides[5] and
arenediazoniumsalts [6–8] has also been reported. More than a decade ago,

MARCEL DEKKER, INC. • 270 MADISON AVENUE • NEW YORK, NY 10016
©2003 Marcel Dekker, Inc. All rights reserved. This material may not be used or reproduced in any form without the express written permission of Marcel Dekker, Inc.
Unsymmetrical Divinylbenzenes
775
we reported a modification of the arenediazonium salt Heck reaction by
using a bimetallic Li2PdCl4–CuCl catalyst systemwith methanol as
solvent, in which the arenediazoniumsalts react with acrylic acid and
methyl acrylate at room temperature to give cinnamic acid and their
esters in high yield (Eq. (1)).[7a] Neither base nor ligand is needed in
the reactions. The simple reaction conditions, short reaction time (usually
completed within 30 min), the small loading of the palladium catalyst
(0.5 mmol%, as compared to the no less than 1–2 mmol% in other
routine practice with arenediazoniumsalt as arylating reagent and
1–2 mmol% in the aryl iodide and bromide reaction) and its easy
availability makes the procedure an exceedingly convenient and practical
procedure for rather large scale preparations.
This procedure is now used in our syntheses of divinylbenzenes,
starting fromthe carboxybenzenediazoniumsalts 1a, 2a and 3a prepared
fromthe corresponding aminobenzoic acids by routine diazotization
procedures. The o-, m- and p-divinylbenzenes 5a–b, 6a–c and 7a were
synthesized by reaction sequences as outlined in Sch. 1.
The first alkenylation reaction takes place at the diazoniumsalt with
Li2PdCl4–CuCl (molar ratio 1:10) as catalyst in the presence of methyl
acrylate in methanol with smooth evolving of nitrogen. The yields are in
all cases high, ranging from83% for the p-isomer to 98% for the
o-isomer. It is known that arenediazonium salts can take part in
Meerwein reaction with acrylic acid or methyl acrylate in aqueous
acetone with CuCl as catalyst to give 3-aryl-2-chloropropanoic acid or
Equation 1.

MARCEL DEKKER, INC. • 270 MADISON AVENUE • NEW YORK, NY 10016
©2003 Marcel Dekker, Inc. All rights reserved. This material may not be used or reproduced in any form without the express written permission of Marcel Dekker, Inc.
776
Wang et al.
Scheme 1.
methyl 3-aryl-2-chloropropanoate in moderate yield by a free radical
mechanism.[15,16] However, in the present case, the arylation reactions
could not proceed in the absence of Li2PdCl4, and typical Heck arylation
products were obtained. Other solvents have also been tried, and it turns
out that the reaction could not take place in MeCN, probably because of
the strong coordination ability of this nitrile solvent to the
palladium(II).[17] In acetone, acetone–dichloromethane (1:1, V/V), ethyl
acetate or in aqueous solution, the reactions proceed only sluggishly with
incomplete nitrogen evolution.
These alkenylated benzoic acids were then transformed into their
benzoyl chloride 4a, 4b and 4c by warming in toluene with thionyl
chloride in 92%, 89% and 90% yield respectively. The second vinyl
functionality was introduced by reaction of 4a, 4b and 4c with the
corresponding olefin with palladiumacetate Pd(OAc)
as catalyst
2
and N,N-dimethylbenzylamine (1.1 equiv. mol) as a base in refluxing
p-xylene. The divinylbenzenes were obtained by flash chromatography.
The yields are given in Table 1. The overall yields starting fromthe
carboxy-arenediazoniumsalts are 57 and 64% for the two p-isomers 5a
and 5b, 47, 44 and 31% for the three m-isomers 6a, 6b and 6c and 40%
for the o-isomer 7a, respectively (see the Experimental).
The large coupling constant (ꢁ18 Hz) between the vicinal olefinic
1
protons in the H NMR spectra of these divinylbenzenes obtained after
chromatographic separation on silica gel column indicated that they all
1
have E-, E-configuration, although the H NMR spectra of the crude
reaction mixture revealed the presence of other geometric isomers

MARCEL DEKKER, INC. • 270 MADISON AVENUE • NEW YORK, NY 10016
©2003 Marcel Dekker, Inc. All rights reserved. This material may not be used or reproduced in any form without the express written permission of Marcel Dekker, Inc.
Unsymmetrical Divinylbenzenes
777
Table 1. Synthesis of divinylbenzenes 5, 6 and 7 fromvinylbenzoic acids 3.a
Divinylbenzenec
Second alkene
Vinylbenzoic Vinylbenzoyl
chlorideb
acid
PhCH¼CH2 CH2¼CHCN CH2¼CHCO2CH3
3a
3b
3c
4a (92)
4b (89)
4c (90)
5a (75)
6a (76)
7a (45)
5b (84)
6b (71)
6c (50)
aIn parenthesis are the yield (%) of isolated pure product.
bGeneral synthetic procedures for 4: the alkenylated benzoic acid, SOCl2 and
DMF were mixed in toluene and stirred at 70ꢀC for 4 h. The reaction mixture
was concentrated in vacuo and the product collected by filtration. The crude
product was recrystallized frompetroleumether (b.p. 60–90 ꢀC) to furnish the
pure aroyl chloride. For reaction scales, see Experimental.
cGeneral synthetic procedures for the divinylbenzenes: Pd(OAc)2 (2–4 mmol%)
and N,N-dimethyl benzylamine were added to a mixture of the corresponding
aroyl chloride and styrene in p-xylene. The reaction mixture was stirred for
18–24 h at 135ꢀC and was then diluted with water and extracted with CHCl3
(3 Â 40 mL). The organic layer was dried with MgSO4 and concentrated in
vacuo. The residue was subjected to column chromatographic separation on a
silica gel column with petroleum ester (b.p. 60–90ꢀC)-ethyl acetate as eluent to
give the product. For reaction scales, see Experimental.
which were transformed to the E-, E-isomer during the chromatographic
separation.
In conclusion, the easier availability and cheapness of the starting
material[1] comparing with bromoiodobenzenes, bromoaroyl chlorides or
iodoarenediazoniumsalts, in combination with the convenient reaction
conditions, the use of Pd(II) instead of Pd(0) and the small loading of the
Pd(II) catalyst, as well as the good overall yield of the divinylbenzenes
make carboxybenzenediazonium salts an advantageous versatile
arylating reagent for practical and efficient synthesis of regioisomeric
symmetric and unsymmetrical divinylbenzenes.
EXPERIMENTAL
Melting points were uncorrected. Proton NMR were recorded on
a Bruker AC-300 spectrometer at 300 MHz in CDCl3. J values are given
in Hz. Infrared spectra were taken with a Shimadzu IR 408 spectrometer

MARCEL DEKKER, INC. • 270 MADISON AVENUE • NEW YORK, NY 10016
©2003 Marcel Dekker, Inc. All rights reserved. This material may not be used or reproduced in any form without the express written permission of Marcel Dekker, Inc.
778
Wang et al.
in KBr pellets. Mass spectra were recorded with a VG ZAB-HS
spectrometer.
Arenediazoniumfluoroborates were prepared by literature proce-
dures.[18] Methanol (A.R. grade) was refluxed with magnesium and
distilled. Alkenes, toluene, p-xylene and N,N-dimethyl benzylamine
were purified by distillation before use. Other reagents (CP or AR
grade) were used as received without further purification. Methanol
solution of Li2PdCl4 was prepared by stirring dry LiCl (0.84 g,
20 mmol) and PdCl2 (1.77 g, 10 mmol) in methanol (100 mL) overnight.
General Procedure for the Synthesis of Divinylbenzenes
Li2PdCl4 (0.05 mmol) and CuCl (0.05 g, 0.5 mmol) were added to a
mixture of the carboxy-benzenediazonium salt (2.36 g, 10 mmol) and
methyl acrylate (0.946 g, 11 mmol) in MeOH (5 mL). The reaction mix-
ture was stirred for about 30 min at room temperature until nitrogen
evolution ceased. The mixture was then cooled to 0ꢂC. The solid product
was collected by filtration. The filtrate was then concentrated, cooled and
filtered again to give another crop of product. The general procedures for
the preparations of the aroyl chlorides 4a–c and of the divinylbenzenes
are given in Table 1.
Preparation of 5a: The p-carboxycinnamic acid 3a was obtained in
83% yield. Reaction of 3a (6.97 g, 31.7 mmol) with SOCl2 (2.75 mL,
37.9 mmol) and DMF (0.09 mL) in toluene (50 mL) for 5 h afforded 4a
(6.53 g, 92%). Refluxing 4a (2.25 g, 10 mmol) with styrene (1.4 mL,
11 mmol) in p-xylene (20 mL) in the presence of Pd(OAc)2 (2 mg,
0.009 mmol) and PhCH2NMe2 (1.65 mL, 11 mmol) at 135ꢂC under a
nitrogen atmosphere for 24 h gave 5a (1.98 g, 75%). The overall yield
starting fromarenediazoniumsalts is 57%.
E,E-Methyl 4-styrylcinnamate (5a): M.p. 182–183ꢂC (yellow solid
frompetroleumether (b.p. 60–90 ꢂC)–ethyl acetate) (lit. 184–186ꢂC[10a]
)
IR 1716, 1634, 1598, 1438, 1172, 972, 820 cmꢀ1. H NMR: ꢀ 3.83 (s, 3H,
CH3), 6.47 (d, J ¼ 16.3 Hz, 1H), 7.20 (d, J ¼ 16.3 Hz, 1H), 7.11
(d, J ¼ 16.3 Hz, 1H), 7.71 (d, J ¼ 16.2 Hz, 1H), 7.30–7.56 (m, 9H, ArH).
MS: m/z 264 [Mþ] (100), 232 (5), 178 (19), 127, 77. Anal. found: C, 81.78;
H, 6.04; calcd. for C18H16O2: C, 81.79; H, 6.10.
1
Preparation of 5b: Refluxing 4a (2.25 g, 10 mmol) with acrylonitrile
(0.73 mL, 11 mmol) in p-xylene (20 mL) in the presence of Pd(OAc)2
(2 mg, 0.009 mmol) and PhCH2NMe2 (1.65 mL, 11 mmol) at 135ꢂC
under a nitrogen atmosphere for 18 h gave 5b (1.79 g, 84%). Overall
yield starting fromarenediazoniumsalts is 64%.

MARCEL DEKKER, INC. • 270 MADISON AVENUE • NEW YORK, NY 10016
©2003 Marcel Dekker, Inc. All rights reserved. This material may not be used or reproduced in any form without the express written permission of Marcel Dekker, Inc.
Unsymmetrical Divinylbenzenes
779
E,E-Methyl 4-(2-cyanoethenyl)cinnamate (5b): M.p. 126–128ꢂC
(white solid frompetroleu-mether (b.p. 60–90
ꢂC)–ethyl acetate)
(lit. 121–122ꢂC[11]). IR: 2210, 1709, 1632, 1426, 1328, 1171, 1121, 973,
1
814 cmꢀ1. H NMR: ꢀ 3.83 (s, 3H, CH3), 5.94 (d, J ¼ 16.7 Hz, 1H), 7.41
(d, J ¼ 16.7 Hz, 1H), 6.50 (d, J ¼ 16.0 Hz, 1H), 7.68 (d, J ¼ 16.0 Hz, 1H),
7.47–7.58 (m, 4H, ArH). MS: m/z 213 [Mþ] (77), 182 (100), 154, 127, 101,
77. Anal. found: C, 73.10; H, 5.13; N, 6.39; calcd. for C13H11NO2:
C, 73.22; H, 5.20; N, 6.57.
Preparation of 6a: The m-carboxycinnamic acid 3b was obtained in
70% yield. Reaction of 3b (5.15 g, 25 mmol) with SOCl2 (2.18 mL,
30 mmol) and DMF (0.01 mL) in toluene (20 mL) for 5 h afforded 4b
(4.98 g, 89%). Refluxing 4b (2.25 g, 10 mmol) with styrene (1.4 mL,
11 mmol) in p-xylene (20 mL) in the presence of Pd(OAc)2 (2 mg,
0.009 mmol) and PhCH2NMe2 (1.65 mL, 11 mmol) at 135ꢂC under
nitrogen for 18 h gave 6a (2.01 g, 76%). The overall yield starting from
2b is 47%.
E,E-Methyl 3-styrylcinnamate (6a): M.p. 140–141ꢂC (white solid
frompetroleum-ether (b.p. 60–90 ꢂC)–ethyl acetate) IR: 1717, 1642,
1436, 1321, 1174, 986, 967, 801, 752, 6939 cmꢀ1 1H NMR: ꢀ 3.85
.
(s, 3H, CH3), 6.51 (d, J ¼ 16.2 Hz, 1H), 7.14 (d, J ¼ 16.4 Hz, 1H), 7.15
(d, J ¼ 16.4 Hz, 1H), 7.74 (d, J ¼ 16.2 Hz, 1H), 7.30–7.67 (m, 9H, ArH).
MS: m/z 264 [Mþ] (100), 232 (13), 203 (54), 178 (28). Anal. found: C,
81.47; H, 5.98; calcd. for C18H16O2: C, 81.79; H, 6.10.
Preparation of 6b: Refluxing 4b (2.25 g, 10 mmol) with acrylonitrile
(0.73 mL, 11 mmol) in p-xylene (20 mL) in the presence of Pd(OAc)2
(4 mg, 0.018 mmol) and PhCH2NMe2 (1.65 mL, 11 mmol) at 135ꢂC
under a nitrogen atmosphere for 24 h gave 6b (1.51 g, 71%). The overall
yield starting from 2b is 44%.
E,E-Methyl 3-(2-cyanoethenyl)cinnamate (6b): M.p. 114–115ꢂC
(white solid frompetroleum-ether (b.p. 60–90 ꢂC)–ethyl acetate) IR:
2212, 1710, 1639, 1618, 1314, 1179, 1197, 987, 854, 791, 677 cmꢀ1
.
1H NMR: ꢀ 3.84 (s, 3H, CH3), 5.95 (d, J ¼ 16.8 Hz, 1H), 7.69
(d, J ¼ 16.2 Hz, 1H), 6.49 (d, J ¼ 16.2 Hz, 1H), 7.40–7.62 (m, 5H, ArH).
MS: m/z 213 [Mþ] (38), 182, 154 (100), 127 (42). Anal. found: C, 73.15; H,
5.02; N, 6.87; calcd. for C13H11NO2: C, 73.22; H, 5.20; N, 6.57.
Preparation of 6c: Refluxing 4b (2.25 g, 10 mmol) with methyl
acrylate (0.99 mL, 11 mmol) in p-xylene (20 mL) in the presence of
Pd(OAc)2 (2 mg, 0.009 mmol) and PhCH2NMe2 (1.65 mL, 11 mmol) at
135ꢂC under a nitrogen atmosphere for 24 h gave 6c (1.23 g, 50%). The
overall yield starting from 2b is 31%.
E,E-Dimethyl 3,30-(1,3-phenylene)bis-2-propanoate(6c):M.p.134–136ꢂC
(white solid frompetroleu-mether (b.p. 60–90
ꢂC)–ethyl acetate)

MARCEL DEKKER, INC. • 270 MADISON AVENUE • NEW YORK, NY 10016
©2003 Marcel Dekker, Inc. All rights reserved. This material may not be used or reproduced in any form without the express written permission of Marcel Dekker, Inc.
780
Wang et al.
(lit. 138ꢂC[19]). IR: 3030, 2954, 1731, 1642, 1577, 1437, 1321, 1170, 979,
1
857, 795, 672 cmꢀ1. H NMR: ꢀ 3.83 (s, 6H, CH3), 6.49 (d, J ¼ 16.0 Hz,
2H), 7.70 (d, J ¼ 16.0 Hz, 2H), 7.40–7.66 (m, 4H, ArH). MS: m/z 246
[Mþ] (0.91), 206 (4.09), 189 (100), 157, 118, 102, 77. Anal. found: C,
68.06; H, 5.39; calcd. for C14H14O4: C, 68.28; H, 5.73.
Preparation of 7a: The o-carboxycinnamic acid 3c was obtained in
98% yield. Reaction of 3c (6.97 g, 31.7 mmol) with SOCl2 (2.75 mL,
37.9 mmol) and DMF (0.09 mL) in toluene (50 mL) for 5 h give 4c
(6.39 g, 90%). Refluxing 4c (2.25 g, 10 mmol) with styrene (1.4 mL,
11 mmol) in p-xylene (20 mL) with Pd(OAc)2 (4 mg, 0.018 mmol) and
PhCH2NMe2 (1.65 mL, 11 mmol) at 135ꢂC under nitrogen for 24 h gave
7a (1.19 g, 45%). The overall yield starting from 2c is 40%.
E,E-Methyl 2-styrylcinnamate (7a): Yellow oil. IR: 1710, 1630, 1595,
1320, 965, 760, 690 cmꢀ1
.
1H NMR: ꢀ 3.83 (s, 3H, CH3), 6.46
(d, J ¼ 15.9 Hz, 1H), 7.19 (d, J ¼ 16.2 Hz, 1H), 7.10 (d, J ¼ 16.2 Hz,
1H), 7.71 (d, J ¼ 15.9 Hz, 1H), 7.30–7.57 (m, 9H, ArH). MS: m/z 264
[Mþ], 232, 205 (100), 178, 161, 131, 91, 77. Anal. found: C, 81.67; H,
6.02; calcd. for C18H16O2: C, 81.79; H, 6.10.
ACKNOWLEDGMENT
This work was supported by the National Natural Science
Foundation of China (Project 20072017).
REFERENCES
1. (a) Beletskaya, I.P.; Cheprakov, A.V. Chem. Rev. 2000, 100, 3009;
(b) Tsuji, J. Palladium Reagents and Catalysts; John Wiley: New
York, 1996; (c) Heck, R.F. In Comprehensive OrganicSynthesis ;
Trost, B.M., Fleming, I., Eds.; Pergamon Press: Oxford, 1991;
Vol. 4, p. 833–863; (d) Heck, R.F. Org. React. (N.Y.) 1982, 27, 345.
2. (a) Blum, J.; Scharf, G. J. Org. Chem. 1970, 35, 1895; (b) Tamaru, Y.;
Yoshida, Z.-I. Tetrahedron Lett. 1978, 4527; (c) Kasahara, A.;
Izumi, T.; Kudou, N.; Azami, H.; Yamamoto, S. Chem. Ind. 1988,
51; (d) Kasahara, A.; Izumi, T.; Mayamoto, K.; Sakai, T. Chem.
Ind. 1989, 192; (e) Miura, M.; Itoh, K.; Nomura, M. Chem. Lett.
1989, 77.
3. (a) Ozawa, F.; Kubo, A.; Hayashi, T. J. Am. Chem. Soc. 1991, 113,
1417; (b) Carpenter, N.E.; Kusera, D.J.; Overman, L.E. J. Org.
Chem. 1989, 54, 5846; (c) Shi, G.-Q.; Huang, X.H.; Hong, F.

MARCEL DEKKER, INC. • 270 MADISON AVENUE • NEW YORK, NY 10016
©2003 Marcel Dekker, Inc. All rights reserved. This material may not be used or reproduced in any form without the express written permission of Marcel Dekker, Inc.
Unsymmetrical Divinylbenzenes
781
J. Chem. Soc. Perkin Trans. 1 1996, 763; (d) Sakuraba, S.; Awano,
K.; Achiwa, K. Synlett 1994, 291.
4. Chen, Q.-Y.; Yang, Z.-Y. Tetrahedron Lett. 1986, 27, 1171.
5. Blaser, H.-U.; Spencer, A. J. Organomet. Chem. 1982, 233, 267.
6. (a) Kikukawa, K.; Matsuda, T. Chem. Lett. 1977, 159;
(b) Kikukawa, K.; Nagira, K.; Wada, F.; Matsuda, T. Tetrahedron
1981, 37, 31; (c) Kikukawa, K.; Maemura, K.; Kiseki, Y.; Wada, F.;
Matsuda, T.; Giam, C.S. J. Org. Chem. 1981, 46, 4885; (d)
Kikukawa, K.; Kono, K.; Wada, F.; Matsuda, T. J. Org. Chem.
1983, 48, 1333; (e) Akiyama, F.; Miyazaki, H.; Kaneda, K.;
Teranishi, S.; Fujiwara, Y.; Abe, M.; Taniguchi, H. J. Org. Chem.
1980, 45, 2359.
7. (a) Xu, J.-H.; Tan, L.-S.; Hu, H.-W. Youji Huaxue, (Chinese Journal
of Organic Chemistry) 1987, 452, CA-109-92408 (1988); (b) Wang,
Y.; Pang, Y.; Zhang, Z.-Y.; Hu, H.-W. Synthesis 1991, 969.
8. (a) Sengupta, S.; Bhattacharya, S. J. Chem. Soc. Perkin Trans. 1
1993, 1943; (b) Sengupta, S.; Bhattacharya, S. Tetrahedron Lett.
1995, 36, 4475; (c) Sengupta, S.; Bhattacharya, S. J. Org. Chem.
1997, 62, 3405.
9. (a) Beller, M.; Fischer, H.; Kuhlein, K. Tetrahedron Lett. 1994, 47,
¨
¨
8773; (b) Beller, M.; Kuhlein, K. Synlett 1995, 441; (c) Darses, S.;
Gene
4393; (d) Brunner, H.; Cousturier de Courcy, N. Le; Gene
Synlett 2000, 201; (e) Darses, S.; Pucheault, M.; Gene
Eur. J. Org. Chem. 2001, 1121.
ˆ
t, J.-P.; Brayer, J.L.; Demoute, J.P. Tetrahedron Lett1.997, 38,
ˆ
t, J.-P.
t, J.-P.
ˆ
10. (a) Plevyak, J.E.; Dickerson, J.E.; Heck, R.F. J. Org. Chem. 1979,
44, 4078; (b) Tao, W.-J.; Nesbitt, S.; Heck, R.F. J. Org. Chem. 1990,
55, 63.
11. Spencer, A. J. Organomet. Chem. 1984, 265, 323.
12. Sengupta, S.; Sadhukhan, S.K. Tetrahedron Lett. 1998, 39, 715.
13. (a) See for example, Moineau, J.; Pozzi, G.; Quici, S.; Sinou, D.
Tetrahedron Lett. 1999, 40, 7683; (b) Bumagin, N.A.;
Andryukhova, N.P.; Beletskaya, I.P. Izv. Akad. Nauk SSSR, Ser.
Khim. 1988, 1449; (c) Wang, P.-W.; Fox, M.A. J. Org. Chem.
1994, 59, 5358.
14. (a) See for example, Patel, B.A.; Ziegler, C.B.; Cortese, N.A.;
Plevyak, J.E.; Zebovitz, T.C.; Terpko, M.; Heck, R.F. J. Org.
Chem. 1977, 42, 3903; (b) Spencer, A. J. Organomet. Chem. 1983,
258, 101; (c) Calo, V.; Nacci, A.; Lopez, L.; Mannarini, N.
Tetrahedron Lett. 2000, 41, 8973.
15. Filler, R.; White, A.B.; Taqui-Khan, B.; Gorelic, L. Can. J. Chem.
1967, 45, 329.

MARCEL DEKKER, INC. • 270 MADISON AVENUE • NEW YORK, NY 10016
©2003 Marcel Dekker, Inc. All rights reserved. This material may not be used or reproduced in any form without the express written permission of Marcel Dekker, Inc.
782
Wang et al.
16. Dickerman, S.C.; DeSouza, D.J.; Fryd, M.; Megna, I.S.; Skoultchi,
M.M. J. Org. Chem. 1967, 34, 14.
17. Overman, L.E.; Knoll, F.M. J. Am. Chem. Soc. 1980, 102, 865.
18. Kolar, G.F.; Naturforsch, Z. Teil B. 1972, 27, 1183.
19. Nakanishi, F.; Nakanishi, H.; Hasegawa, M. J. Polym. Sci. Polym.
Chem. Ed. 1975, 13, 2499.
Received in Japan December 25, 2001