Enyne synthesis through a modified Sonogashira cross-coupling reaction catalyzed by cyclopalladated complexes

Article abstract of DOI:10.1016/j.tet.2011.09.110

A series of conjugated enynes were successfully synthesized by the palladacycle-catalyzed modified Sonogashira cross-coupling reaction of β-bromostyrene and terminal alkynes. The reaction proceeds smoothly in DMSO at 40 °C to give the corresponding produc

Full text of DOI:10.1016/j.tet.2011.09.110

Tetrahedron 68 (2012) 376e381
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Enyne synthesis through a modified Sonogashira cross-coupling reaction
catalyzed by cyclopalladated complexes
*
Mengmeng Huang, Yujian Feng, Yangjie Wu
Chemistry Department, Henan Key Laboratory of Chemical Biology and Organic Chemistry, Key Laboratory of Applied Chemistry of Henan Universities, Zhengzhou University,
Zhengzhou, 450052, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 2 July 2011
Received in revised form 19 September 2011
Accepted 23 September 2011
Available online 29 September 2011
A series of conjugated enynes were successfully synthesized by the palladacycle-catalyzed modified
Sonogashira cross-coupling reaction of
b-bromostyrene and terminal alkynes. The reaction proceeds
smoothly in DMSO at 40 ꢀC to give the corresponding products in moderate to excellent yields. This
catalytic system is tolerant to a broad range of functional groups on the substrates. Moreover, the
products were furnished as specific E isomers. We also found that the product of the reaction between
(E)-
b
-bromostyrene and 2-methyl-3-butyn-2-ol is diarylated enyne in the presence of excess Cs2CO3.
Keywords:
Cyclopallated ferrocenyl complexes
CuBr
Ó 2011 Elsevier Ltd. All rights reserved.
Sonogashira reaction
(E)-b-Bromostyrene
Terminal alkyne
1. Introduction
results of palladacycle-catalyzed cross-coupling reaction of b-bro-
mostyrene with terminal alkynes, which is a modified Sonogashira
reaction by using the palladacycles I, II or III as a catalyst.
The conjugated enyne is a structure of high interest owing to its
presence in many natural products and biologically active com-
pounds1. For example, the skeleton of conjugated enyne is present
in the molecule of trans-ku-mausyne, Calicheamycin, and Terbi-
nafine2. So development of a method for synthesis of these com-
pounds becomes one of the major directions in organic chemistry.
Usually Sonogashira cross-coupling reaction3e7 catalyzed by the
palladium complexes was used to prepare them. Moreover, there
were large numbers of publications, concerning Sonogashira re-
action catalyzed by other metal complexes, e.g., Ni8, Cu(I),9 and
Cu(II)10 complexes, but the reactions usually proceed under severe
2. Results and discussion
reaction conditions or with phosphorous-containing additives11e13
.
For optimization of the reaction conditions, we chose the cross-
coupling of (E)-b-bromostyrene with phenylactylene as model re-
Currently, the catalyst of cyclopalladated complexes became one
of the most popular catalysts in catalytic chemistry14e16. Especially,
the palladium complexes containing ferrocenyl fragment have been
action, and the effects of the base, catalyst, solvent, copper salt
additive (Cu(I)X) and temperature were examined. The results were
summarized in Table 1. It was found that this reaction proceeded in
the presence of weak base Cs2CO3 (entry 4) giving product 3a.
Similar results have also been reported by other authors27, and in
this case, the ion Csþ could be considered as an auxiliary compo-
nent for the reaction. In addition, without palladium complex, CuI
appeared no catalytic activity (entry 8). Otherwise, the yield of
product 3a catalyzed by Cat.I reached to 70% at 100 ꢀC (entry 6). We
found that the polarity of aprotic solvents have dramatic influence
on Sonogashira reaction, i.e., the stronger polarity of the solvent,
the higher yield of the reaction (entries 6 and 10e13). However,
the most developed and extensively studied in our laboratory17e20
,
owing to their structural versatility, stability, and easily synthetic
accessibility. They have
a ,
high catalytic activity in Heck21
Suzuki,22,23 and other reactions24e26. However, these palladium
complexes have not applied in modified Sonogashira reaction using
b-bromostyrene as substrate. So in this paper, we will report the
* Corresponding author. Tel./fax: þ86 371 67766667; e-mail address: wyj@
zzu.edu.cn (Y. Wu).
0040-4020/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2011.09.110

M. Huang et al. / Tetrahedron 68 (2012) 376e381
377
Table 1
Optimization of the reaction conditions for the formation of 3aa
Entry
Catalyst
Additive
Base
Solvent
T (ꢀC)
Yielde [%]
1
2
3
4
5
6
7
8
Cat.III
Cat.III
Cat.III
Cat.III
Cat.III
Cat.I
Cat.II
d
CuI
CuI
CuI
CuI
CuI
CuI
CuI
CuI
CuBr
CuBr
CuBr
CuBr
CuBr
CuBr
CuCl
CuI
K2CO3
CsF
NaOAc
Cs2CO3
K3PO4
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
100
100
100
100
100
100
100
100
100
100
100
66
12
NRb
NR
52
NRb
70
65
NRb
76
86
22
21
64
38
73
82
17
77
80
82
91
27
57
85
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
9
Cat.I
Cat.I
Cat.I
Cat.I
Cat.I
Cat.I
Cat.I
Cat.I
Cat.I
Cat.I
Cat.I
Cat.I
Cat.I
Cat.I
Cat.Ic
Cat.Id
DMF
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
DMSO
1,4-Dioxane
THF
Acetone
MeOH
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
65
57
100
100
100
120
80
60
40
30
40
d
CuBr
CuBr
CuBr
CuBr
CuBr
CuBr
CuBr
40
The values in bold represent the the optimized condition for the studied reaction.
a
Reaction conditions: catalyst (1 mol %), additive (20 mol %), base (1 mmol), (E)-b-bromostyrene (0.5 mmol), phenylacetylene (0.75 mmol), solvent (3 mL), 24 h, N2.
No reaction.
Catalyst (0.5 mol %).
Catalyst (2 mol %).
b
c
d
e
Isolated yield.
using the protic solvents, yield of product 3a decreased drastically
to 38% (entry 14). In the absence of CuX, the reaction proceeded
slowly (24 h) with a low yield (17%, entry17), and the optimal ac-
tivity of CuX for this reaction is CuBr (entries 10 and 15e16). Fur-
thermore, it was found that the reaction temperature has certain
influence on the reaction yields, but this relationship is not com-
pletely regular (entries 10 and 18e22). If the loading of catalyst I
was reduced (0.5 mol %, entry 23) or increased (2 mol %, entry 24),
the corresponding yields were reduced. Therefore, the optimized
conditions of palladacycle-catalyzed cross-coupling reaction of (E)-
activity in Sonogashira reaction between (E)-
alkyl terminal alkynes (Table 3, entries 1e3). Using the catalyst II,
the reactions of (E)- -bromostyrene with alkyl terminal alkynes2k
and 2l proceeded smoothly, and the corresponding yield of these
reactions rapidly increased to 75% and 89% (entries 4e6) However,
b-bromostyrene and
b
when we studied the reaction of (E)-b-bromostyrene with 2-
methyl-3-butyn-2-ol (2m), it was found that the product of this
reaction was compound 3m. We assumed that this reaction might
proceed with formation of unstable monoarylated enyne 4 at first
and then excess Cs2CO3 led to the formation of compound 3m28
(Fig. 1).
b
-bromostyrene with terminal alkynes includes the following pa-
rameters: -bromostyrene (0.5 mmol), terminal alkyne
b
(0.75 mmol), Cat.I (1 mol %), CuBr (20 mol %), Cs2CO3 (1 mmol),
3. Conclusion
DMSO (3 mL), N2, at 40 ꢀC in 24 h.
Under these optimized conditions, we examined the substrate
scope. The results indicated that the cyclopalladated complex I
constituted a highly efficient catalyst for Sonogashira reaction of
bromostyrene with terminal alkynes (Table 2). Both the electron-
rich (deactivated) and electron-poor (activated) terminal alkynes
could be converted to the desirable products 3aei (entries 1e9),
but yield of products containing electron-rich groups (entries 1e6)
is appreciably higher than the products containing electron-poor
groups (entries 7e9). Moreover, the location of the radical con-
tained in terminal alkynes also influences on the yield of the
products. Product yields of p-substituted terminal alkynes are al-
ways higher than that of o- and m-substituted compounds.
In summary, we have found a mild and efficient catalytic system
for the direct synthesis of conjugated enynes by using the
palladacycle-catalyzed coupling of
b-bromostyrene and alkynes.
We have studied Sonogashira coupling reaction with the pallada-
cycle catalysts, which were synthesized and discovered as a popu-
lar catalyst in our laboratory. This catalytic system has wide
functional-group tolerance on substrates. This novel catalytic sys-
tem provides a very useful supplement to the known methods for
enyne synthesis in terms of economy, ecology, and easy workup.
4. Experimental
However, the (Z)-b-bromostyrene 1b could not react with phenyl-
acetylene 2a (entry 10).
4.1. General methods
1H NMR and 13C NMR spectra were recorded on a Bruker DPX
400 instrument using CDCl3 as the solvent and TMS as the internal
Despite the conditions of this reaction have been optimized, it
was found that catalyst I in this case does not have any catalytic

378
M. Huang et al. / Tetrahedron 68 (2012) 376e381
Table 2
Preparation of enynes from bromostyrene with terminal alkynesa
I
Cat. , CuBr
R1
R1Br
+
R
Cs2CO3/DMSO, 40 oC
R
1a-b
2 a-j
3 a-j
Entry
1
Catalyst
R1Br
Alkyne
Product
Yieldc [%]
Br
Cat.I
91
3a
1a
2a
CH3
H3C
2
3
Cat.I
Cat.I
1a
1a
94
83
2b
3b
CH3
H3C
2e
3c
C(CH3)3
(H3C)3C
4
Cat.I
1a
75
2d
3d
NH2
H2N
5
Cat.I
1a
82
2e
3e
OCH3
CH3O
6
Cat.I
1a
81
2f
3f
Br
Br
7
Cat.I
1a
48
2g
3g
F
F
8
Cat.I
1a
77
2h
3h

M. Huang et al. / Tetrahedron 68 (2012) 376e381
379
Table 2 (continued )
Entry
Catalyst
R1Br
Alkyne
Product
Yieldc [%]
F3C
F3C
9
Cat.I
1a
49
2i
3i
10
Cat.I
d
NRb
Br
1b
2a
a
Reaction conditions:
No reaction.
Isolated yield.
b
-bromostyrene (0.5 mmol), terminal alkyne (0.75 mmol), catalyst (1 mol %), CuBr (20 mol %), Cs2CO3 (1 mmol) in DMSO (3 mL) at 40 ꢀC for 24 h, N2.
b
c
Table 3
Preparation of enynes from (E)-
b
-bromostyrene with terminal alkynesa
Br
R
Cat I or II, CuBr
+
R
Cs2CO3 / DMSO, 40 oC
1
2 k-m
3 k-m
Entry
1
Catalyst
Alkyne
Product
Yield [%]
NRb
HC
C(CH2)5CH3
Cat.I
d
2k
HC
HC
C(CH2)4CH3
2
3
Cat.I
Cat.I
d
d
NRb
NRb
2l
OH
2m
(CH2)5CH3
(CH2)4CH3
HC
HC
C(CH2)5CH3
4
5
Cat.II
Cat.II
75
89
2k
3k
C(CH2)4CH3
2l
3l
HC
OH
6
Cat.II
77
2m
3m
a
Reaction conditions: (E)-b
-bromostyrene (0.5 mmol), terminal alkyne (0.75 mmol), catalyst (1 mol %), CuBr (20 mol %), Cs2CO3 (1 mmol) in DMSO (3 mL) at 40 ꢀC for
24 h, N2.
b
No reaction.
standard. EA data were recorded on Elementar Vario ELIIIspec-
trometer. Melting points were measured using a WC-1 microscopic
apparatus and are uncorrected. Preparative TLC was performed on
dry silica gel plates developed with petroleum/EtOAc.
All solvents were purified by the standard methods. (E)-
mostyrene and all the alkynes were purchased from commercial
sources and generally used without further purification. (Z)-
Bromostyrene was prepared according to the reported procedure29
b-bro-
b
-
.

380
M. Huang et al. / Tetrahedron 68 (2012) 376e381
Fig. 1. The mechanism of Cat.II catalyzed cross-coupling reaction of (E)-b-bromostyrene with 2-methyl-3-butyn-2-ol.
All of the products 3aem except 3c, 3d, and 3i were known and the
purified products were identified by comparison of melting points,
1H NMR or 13C NMR spectra with the literatures.
aromatic carbons), 91.97 (C^), 88.24 (C^), 21.48 (CH3). Anal.
Calcd for C17H14 (218.29): C, 93.54; H, 6.46. Found: C, 93.47; H,
6.40%.
4.2.3. (E)-1-Phenyl-4-m-methylphenylbut-1-en-3-yne (3c). Yellow
4.2. General procedure for synthesis of enynes
oil; 1H NMR (400 MHz, CDCl3):
d 7.37e7.44, 7.26e7.35, 7.15e7.23,
7.05e7.13 (m, 9H, aromatic hydrogens), 7.02 (d, J¼16.14 Hz, 1H,
To a Schlenk tube was charged with catalyst (1 mol %), CuBr
(20 mol %), Cs2CO3 (1 mmol). The vessel was then evacuated and
backfilled with nitrogen. (E)-b-Bromostyrene (1.0 mmol), the ter-
minal alkyne (1.2 mmol), and DMF (3 mL) were successively added.
The reaction tube was quickly sealed, and the contents were stirred
at 40 ꢀC for 24 h. Then, the reaction mixture was dissolved in H2O
and extracted with CH2Cl2. The combined organic layer was dried
(MgSO4). The product was further purified by silica gel column
chromatography.
CH]), 6.36 (d, J¼16.14 Hz, 1H, CH]), 2.31 (s, 3H, CH3); 13C NMR
(100 MHz, CDCl3):
d 141.06, 137.94, 136.31, 132.04, 129.07, 128.67,
128.56, 128.52, 128.20, 126.24, 123.18, 108.19 (CH]CH group and
aromatic carbons), 91.95 (C^), 88.55 (C^), 21.17 (CH3). Anal.
Calcd for C17H14 (218.29): C, 93.54; H, 6.46. Found: C, 93.45; H,
6.50%.
4.2.4. (E)-1-Phenyl-4-p-tretbutylphenylbut-1-en-3-yne (3d). White
solid, mp 82e84 ꢀC; 1H NMR (400 MHz, CDCl3):
d 7.38e7.44,
7.26e7.37 (m, 9H, aromatic hydrogens), 7.02 (d, J¼16.45 Hz, 1H,
4.2.1. (E)-1,4-Diphenylbut-1-en-3-yne (3a)30. White solid, mp
CH]), 6.38 (d, J¼16.45 Hz, 1H, CH]), 1.31 (s, 9H, CH3); 13C NMR
96e97 ꢀC (lit. 96e97 ꢀC); 1H NMR (400 MHz, CDCl3):
d 7.47 (d,
(100 MHz, CDCl3):
d 151.48, 140.84, 136.44, 131.24, 128.71, 128.49,
J¼7.6 Hz, 2H, aromatic hydrogens), 7.41 (d, J¼7.2 Hz, 2H, aromatic
hydrogens), 7.33e7.26 (m, 6H, aromatic hydrogens), 7.03 (d,
J¼16.4 Hz, 1H, CH]), 6.37 (d, J¼16.0 Hz, 1H, CH]); 13C NMR
126.25, 125.34, 120.38, 108.36 (CH]CH group and aromatic car-
bons), 91.97 (C^), 88.25 (C^), 34.77(CMe3), 31.16 (3CH3). Anal.
Calcd for C20H20 (260.37): C, 92.26; H, 7.74. Found: C, 92.15; H,
7.72%.
(100 MHz, CDCl3):
d 141.2, 136.3, 131.5, 128.7, 128.6, 128.3, 128.2,
126.3, 123.4, 108.1 (CH]CH group and aromatic carbons), 91.8
(C^), 88.9 (C^).
4.2.5. (E)-1-Phenyl-4-p-methoxyphenylbut-1-en-3-yne (3f)32. White
solid, mp 49e51 ꢀC (lit. 48e50 ꢀC); 1H NMR (400 MHz, CDCl3):
4.2.2. (E)-1-Phenyl-4-tolylbut-1-en-3-yne (3b)31. White solid, mp
d
7.38e7.44, 7.25e7.36, 6.80e6.87 (3 m, 9H, aromatic hydrogens),
7.00 (d, J¼16.14 Hz, 1H, CH]), 6.37 (d, J¼16.14 Hz, 1H, CH]), 3.81
(s, 3H, CH3O); 13C NMR (100 MHz, CDCl3):
159.60, 140.44,
74e75 ꢀC (lit. 75e76 ꢀC); 1H NMR (400 MHz, CDCl3):
d 7.25e7.45,
7.10e7.17 (2 m, 9H, aromatic hydrogens), 7.01 (d, J¼16.14 Hz,
d
1H, CH]), 6.37 (d, J¼16.14 Hz, 1H, CH]), 2.35 (s, 3H, CH3);
136.49, 132.97, 128.71, 128.43, 126.21, 115.54, 114.02, 108.40 (CH]
CH group and aromatic carbons), 91.84 (C^), 87.65 (C^), 55.28
(CH3).
13C NMR (100 MHz, CDCl3):
d 140.84, 138.33, 136.41, 132.37,
131.40, 129.11, 128.70, 126.24, 120.31, 108.30 (CH]CH group and

M. Huang et al. / Tetrahedron 68 (2012) 376e381
381
4.2.6. (E)-1-Phenyl-4-m-aminophenylbut-1-en-3-yne (3e)33. Brown
solid, mp 88e89 ꢀC (lit. 88e89 ꢀC); 1H NMR (400 MHz, CDCl3):
d 141.12, 136.31, 128.72, 128.61, 126.28, 108.23(CH]CH group and
aromatic carbons), 93.08 (C^).
d
7.38e7.44, 7.26e7.36, 7.08e7.14, 6.85e6.92, 6.75e6.82, 6.59e6.68
(6 m, 9H, aromatic hydrogens), 7.02 (d, J¼16.45 Hz, 1H, CH]), 6.89
Acknowledgements
(d, J¼7.31 Hz, 1H, CH]), 3.99e3.05 (br s, 2H, NH2); 13C NMR
(100 MHz, CDCl3):
d 146.22, 141.07, 136.34, 129.24, 128.68, 128.52,
We are grateful to the National Natural Science Foundation of
China (No. 20772114) and the Innovation Fund for Outstanding
Scholar of Henan Province (No. 0621001100) for financial support
to this research.
126.24, 124.03, 121.99, 117.66, 115.28, 108.20 (CH]CH group and
aromatic carbons), 91.99 (C^), 88.26 (C^).
4.2.7. (E)-1-Phenyl-4-p-bromophenylbut-1-en-3-yne (3g)31. Yellow
solid, mp 113e114 ꢀC (lit. 113e114 ꢀC); 1H NMR (400 MHz, CDCl3):
References and notes
d
7.49e7.40, 7.38e7.27 (2 m, 9H, aromatic hydrogens), 7.04 (d,
J¼16.45 Hz, 1H, CH]), 6.35 (d, J¼16.45 Hz, 1H, CH]); 13C NMR
1. Wakatsuki, Y. J. Organomet. Chem. 2004, 689, 4092e4109.
2. Evans, D. A.; Burch, J. D. Org. Lett. 2001, 3, 503e505.
3. Wang, Y.; Xu, J. J.; Burton, D. J. J. Org. Chem. 2006, 71, 7780e7784.
4. Hundertmark, T.; Littke, A. F.; Buchwald, S. L.; . Fu, G. C. Org. Lett. 2000, 2,
1729e1731.
5. Beauperin, M.; Job, A.; Cattey, H.; Royer, S.; Meunier, P.; Hierso, J.-C. Organo-
metallics 2010, 29, 2815e2822.
(100 MHz, CDCl3):
d 141.73, 136.17, 132.89, 131.61, 128.76, 126.34,
122.38, 107.78 (CH]CH group and aromatic carbons), 90.59 (C^),
90.03 (C^).
4.2.8. (E)-1-Phenyl-4-p-fluorophenylbut-1-en-3-yne (3h)34. White
6. Gu, Z.; Li, Z. Z.; Liu, Z. C.; Wang, Y.; Liu, C. B.; . Xiang, J. N. Catal. Commun. 2008, 9,
2154e2157.
solid, mp 83e85 ꢀC; 1H NMR (400 MHz, CDCl3):
d 7.38e7.49,
7. Fukuyama, T.; Shinmen, M.; Nishitani, S.; Sato, M.; Ryu, I. Org. Lett. 2002, 4,
1691e1694.
8. Vechorkin, O.; Barmaz, D.; Proust, V.; Hu., X. J. Am. Chem. Soc. 2009, 131,
12078e12079.
7.26e7.23, 6.98e7.08 (3 m, 10H, aromatic hydrogens and CH]
group), 6.36 (d, J¼16.45 Hz, 1H, CH]); 13C NMR (100 MHz, CDCl3):
d
163.68, 141.33, 136.26, 133.40, 133.32, 128.66, 119.51, 115.75,
9. Okuro, K.; Furuune, M.; Enna, M.; Miura, M.; Nomura, M. J. Org. Chem. 1993, 58,
4716e4721.
10. Guo, S. M.; Deng, C. L.; Li, J. H. Chin. Chem. Lett. 2007, 18, 13e16.
11. Lauterbach, T.; Livendahl, M.; Rosellon, A.; Espinet, P.; Echavarren, A. M. Org.
Lett. 2010, 12, 3006e3009.
115.53, 107.93 (CH]CH group and aromatic carbons), 90.61 (C^),
88.55 (C^); Anal. Calcd for C16H11F (222.08): C, 86.46; H, 4.99.
Found: C, 86.95; H, 5.06%.
12. Sawant, D. N.; Tambade, P. J.; Wagh, Y. S.; Bhanage, B. M. Tetrahedron Lett. 2010,
51, 2758e2761.
13. Negishi, E.; Shi, J.; Zeng, X. Z. Tetrahedron 2005, 61, 9886e9895.
14. Chellan, P.; Nasser, S.; Vivas, L.; Chibale, K.; Smith, G. S. J. Organomet. Chem.
2010, 695, 2225e2232.
15. Kozlov, V. A.; Aleksanyan, D. V.; Nelyubina, Y. V.; Lyssenko, K. A.; Gutsul, E. I.;
Puntus, L. N.; Vasil’ev, A. A.; Petrovskii, P. V.; Odinets, I. L. Organometallics 2008,
27, 4062e4070.
16. Moro, A. C.; Mauro, A. E.; Netto, A. V. G.; Ananias, S. R.; Quilles, M. B.; Carlos, I.
Z.; Pavan, F. R.; Leite, C. Q. F.; Horner, M. Eur. J. Med. Chem. 2009, 44, 4611e4615.
17. Wu, Y. J.; Hou, J. J.; Yun, H. Y.; Cui, X. L.; Yuan, R. J. J. Organomet. Chem. 2001,
637e639, 793e795.
4.2.9. (E)-1-Phenyl-4-o-trifluoromethylphenylbut-1-en-3-yne
(3i). Yellow oil, 1H NMR (400 MHz, CDCl3):
d 7.60e7.72,
7.44e7.54, 7.29e7.44 (3 m, 9H, aromatic hydrogens), 7.10 (d,
J¼16.14 Hz, 1H, CH]), 6.42 (d,J¼16.14 Hz, 1H, CH]), 13C NMR
(100 MHz, CDCl3):
d 136.10, 135.07, 133.77, 132.62, 131.37, 129.50,
128.78, 128.48, 127.80, 126.50, 125.92, 125.87, 107,67 (CH]CH
group and aromatic carbons), 94.46 (C^), 87.42 (C^); Anal.
Calcd for C17H11F3 (272.08): C, 74.99; H, 4.07. Found: C, 74.42; H,
4.14%.
18. Wu, Y. J.; Yang, L. R.; Zhang, J. L.; Wang, M.; Zhao, L.; Song, M. P.; Gong, J. F.;
Yang, L. R.; Zhang, J. L. Archive Org. Chem. 2004, 9, 111e121.
19. Gong, J. F.; Liu, G. Y.; Zhu, Y.; Du, C. X.; Song, M. P.; Wu, Y. J. Chem. J. Chinese U.
2006, 27, 1266e1271.
4.2.10. (E)-1-Phenyl-4-octynylbut-1-en-3-yne (3k)35. Yellow oil, 1H
NMR (400 MHz, CDCl3):
d 7.21e7.40 (m, 5H, aromatic hydrogens),
20. Zhang, J. L.; Wu, Y. J.; Li, J. Y.; Du, C. X.; Zheng, J. M.; Mai, S. W.; Song, M. P. Chem.
6.87 (d, J¼16.63 Hz, 1H, CH]), 6.16 (d, J¼16.63 Hz, 1H, CH]),
J. Chinese U. 2007, 28, 2311e2315.
2.32e2.40, 1.51e1.61, 1.37e1.50, 1.23e1.36 (4 m, 10H, CH2), 0.90 (t,
21. Ren, G. R.; Cui, X. L.; Yang, E. B.; Yang, F.; Wu, Y. J. Tetrahedron 2010, 66, 4022e4028.
22. Li, H.; Wu, Y. J.; Yan, W. B. J. Organomet. Chem. 2006, 691, 5688e5696.
23. Zhang, J. L.; Yang, F.; Ren, G. R.; Mak, T. C. W.; Song, M. P.; Wu, Y. J. Ultrason.
Sonochem. 2008, 15, 115e118.
24. Yang, F.; Wu, Y. J. Eur. J. Org. Chem. 2007, 3476e3479.
25. Li, J. Y.; Cui, M. J.; Yu, A. J.; Wu, Y. J. J. Organomet. Chem. 2007, 692, 3732e3742.
26. Yu, A. J.; Wu, Y. J.; Cheng, B. L.; Wei, K.; Li, J. Y. Adv. Synth. Catal. 2009, 351,
767e771.
27. Duan, X.-F.; Zhang, Z.-B. Chin. J. Org. Chem. 2006, 26, 573e578.
28. Novak, Z.; Nemes, P.; Kotschy, A. Org. Lett. 2004, 6, 4917e4920.
29. Kim, S. H.; Wei, H. X.; Willis, S.; Li, G. G. Synth. Commun. 1999, 29, 4179e4185.
30. Shim, S. C.; Suh, M. C.; Kim, D. S. J. Polym. Sci., Part A: Polym. Chem. 1996, 34,
3131e3139.
J¼6.85 Hz, 3H, CH3); 13C NMR (100 MHz, CDCl3):
d 139.90, 136.53,
128.62, 128.18, 126.01, 108.84 (CH]CH group and aromatic car-
bons), 93.06 (C^), 79.64 (C^), 31.34, 28.72, 28.59, 22.53, 19.62
(CH2), 14.04 (CH3).
4.2.11. (E)-1-Phenyl-4-heptynylbut-1-en-3-yne (3l)36. Yellow oil, 1H
NMR (400 MHz, CDCl3):
d 7.22e7.41 (m, 5H, aromatic hydrogens),
6.87 (d, J¼16.63 Hz, 1H, CH]), 6.16 (d, J¼16.63 Hz, 1H, CH]),
2.41e2.32, 1.66e1.51, 1.49e1.28 (3 m, 8H, CH2), 0.92 (t, J¼7.10 Hz,
3H, CH3); 13C NMR (100 MHz, CDCl3):
d 139.91, 136.53, 128.60,
31. Bhaskar, R. D.; Chandrasekhar, B. N.; Padmavathi, V.; Padmaja, A. Tetrahedron
128.16, 126.00, 108.85 (CH]CH group and aromatic carbons),
93.08 (C^), 79.67 (C^), 31.11, 28.49, 22.24, 19.62 (CH2), 14.00
(CH3).
1997, 53, 17351e17360.
32. Liu, Y. Y.; Yang, J. G.; Bao, W. L. Eur. J. Org. Chem. 2009, 5317e5320.
33. Harris, F. W.; Pamidimukkala, A.; Gupta, R.; Das, S.; Wu, T.; Mock, G. J. Marcoml.
Sci., Chem. 1984, A21, 1117e1135.
34. Hofmann, J.; Zimmermann, G.; Homann, K.-H. Liebigs Ann. 1995, 841e848.
35. Hatakeyama, T.; Yoshimoto, Y.; Gabriel, T.; Nakamura, M. Org. Lett. 2008, 10,
5341e5344.
36. Li, J. H.; Li, J. L.; Wang, D. P.; Pi, S. F.; Xie, Y. X.; Zhang, M. B.; Hu, X. C. J. Org.
Chem. 2007, 72, 2053e2057.
4.2.12. 1,6-Diphenyl-1,5-hexadien-3-yne (3m)37. Yellow solid, mp
57e59 ꢀC (lit. 58e60 ꢀC); 1H NMR (400 MHz, CDCl3):
d 7.38e7.46,
7.28e7.37 (m, 10H, aromatic hydrogens), 6.98 (d, J¼15.65 Hz, 2H,
CH]), 6.35 (d, J¼15.65 Hz, 2H, CH]); 13C NMR (100 MHz, CDCl3):
37. Sonoda, M.; Itahashi, K.; . Tobe, Y. Tetrahedron Lett. 2002, 43, 5269e5272.