Synthesis of 1,4-dienes by Pd(II)-catalyzed haloallylation of alkynes with allylic alcohols in ionic liquids

Article abstract of DOI:10.1016/j.tet.2013.10.100

A Pd-catalyzed haloallylation of alkynes with allyl alcohols in ionic liquids has been reported. Both chloroallylation and bromoallylation can be easily carried out with high selectivity. A variety of 1,4-dienes were formed in moderate to excellent yields. The reaction system of the Pd catalyst as well as the ionic liquid can be recycled for several times. And the ionic liquid acts as not only a solvent in the reaction, but also provides the excess halide ions to control Z/E selectivity and acts as a ligand inhibit the β-hydride elimination.

Full text of DOI:10.1016/j.tet.2013.10.100

Tetrahedron 70 (2014) 1516e1523
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Synthesis of 1,4-dienes by Pd(II)-catalyzed haloallylation of alkynes
with allylic alcohols in ionic liquids
*
Jianxiao Li, Shaorong Yang , Wanqing Wu, Chaorong Qi, Zhongxian Deng,
*
Huanfeng Jiang
School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, People’s Republic of China
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 3 August 2013
Received in revised form 22 October 2013
Accepted 31 October 2013
Available online 6 November 2013
A Pd-catalyzed haloallylation of alkynes with allyl alcohols in ionic liquids has been reported. Both
chloroallylation and bromoallylation can be easily carried out with high selectivity. A variety of 1,4-
dienes were formed in moderate to excellent yields. The reaction system of the Pd catalyst as well as
the ionic liquid can be recycled for several times. And the ionic liquid acts as not only a solvent in the
reaction, but also provides the excess halide ions to control Z/E selectivity and acts as a ligand inhibit the
b
-hydride elimination.
Keywords:
Ó 2014 Published by Elsevier Ltd.
Alkynes
Allyl alcohols
Palladium-catalyzed
1,4-Dienes
Ionic liquids
1. Introduction
One of the complications in palladium-catalyzed alkyne/allyl
alcohol reaction is the strong tendency for the alkylpalladium in-
In recent decades, the synthesis of 1,4-dienes has attracted
much attention, and a series of synthetic approaches related to the
reaction of alkynes have been developed.1,2 Among these strategies,
palladium-catalyzed haloallylation of alkynes with allylic moiety
has been recognized to be an effective method because of the good
selectivity and mild reaction conditions. Although allylic alcohols
are commercially available, the allylating reagents in the reaction
have usually been limited to allylic chlorides, allylic bromides, and
allylic acetates.2 Obviously, it will greatly enlarge the scope and
synthetic application field of alkyne haloallylation if allylic alcohols
can be directly used in the reaction. In our previous work, we
successfully performed the reaction to produce 1,4-dienes in an
aqueous media by employing alkynes and allyl alcohols.2f Upon
exploring the reaction, it was found that the ionic liquids worked
more efficiently for this process and produced 1,4-dienes in high
selectivity with moderate to excellent yields. Herein, we report
a method for highly efficient synthesis of 1,4-dienes by Pd(II)-
catalyzed haloallylation of alkynes with allyl alcohols in aqueous
ionic liquids.
termediates to undergo a
b
-hydride elimination to yield
g,d-un-
saturated carbonyl compounds (Scheme 1).3 Obviously, if
b
-hydride
elimination was suppressed, alternative reactions of the alkylpal-
ladium species would be promoted. In our previous work,4 it was
found that
b-hydride elimination could be inhibited in a PdCl2-
[Bmim]CleHCl system. In this system, the ionic liquid provides the
excess chloride ions to control Z/E selectivity5 and acts as a ligand
inhibit the b
-hydride elimination.4
Scheme 1. Palladium-catalyzed bromoalkylation of alkynoates.
Thus, we chose this system to investigate the palladium-
catalyzed alkyne/allyl alcohol reaction.
2. Results and discussion
Synthesis of (1Z) or (1E) 1,4-dienes. The reaction of ethyl 3-
phenylpropiolate (1a) and prop-2-en-1-ol (2a) was first investigated
* Corresponding authors. Tel./fax: þ86 20 87112906; e-mail addresses: lisryang@
scut.edu.cn (S. Yang), jianghf@scut.edu.cn (H. Jiang).
0040-4020/$ e see front matter Ó 2014 Published by Elsevier Ltd.
http://dx.doi.org/10.1016/j.tet.2013.10.100

J. Li et al. / Tetrahedron 70 (2014) 1516e1523
1517
in the presence of 5 mol % of PdCl2 in 1 mL mixed solvents ([Bmim]
Cl:12 N aqueous HCl¼3:1). To our delight, the reaction produced the
desired (Z)-3aa in 98% GC yield with an excellent Z-stereoselectivity
(Z/E¼98/2 by GC) after stirring for 24 h at room temperature and no
such as H2O and DMSO, significantly decreased the yields and
stereoselectivities (entries 11, 12). Other halide sources, such as
NaCl and LiCl, were tested as a convenient source of halogens,
unfortunately, the products were produced in lower selectivities
(entries 13,14). Accordingly, different catalytic loading and the
solvent systems were examined to improve the reaction efficiency
(entries 15e20). After many attempts, 3 mol % of PdCl2 as the cat-
alyst, 0.5 mL of [C2O2mim]Cl and 0.25 mL of HCl as the solvent were
found to be the best choices, providing 3aa in 100% yield with an
excellent Z-stereoselectivity (Z/E>98/2 by GC). Moreover, diallyl
ether was observed in the reaction mixture.6
carbonyl compounds were detected. The results demonstrated that b-
hydride elimination could be inhibited. Encouraged by this result, we
further investigated the reaction conditions and the results are listed
in Table 1.
Table 1
Optimization of reaction conditionsa
Entry Solvent (mL)
Pd (mol %) GC yieldb (%) Z/Ec
1
2
[Bmim]Cl (0.75)þ12 N HCl (0.25)
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
2
3
3
d
d
d
d
d
d
98
78
55
87
97
98/2
98/2
98/2
95/5
98/2
d
Fig. 1. Ionic liquids applied in this work.
[Bmim]Cl (0.75)þ12 N HCl (0.15)
[Bmim]Cl (0.75)þ12 N HCl (0.1)
[Bmim]Cl (0.75)þ12 N HCl (0.25)
[Bmim]Cl (0.5)þ12 N HCl (0.25)
[Bmim]Cl (0.5)þH2O (0.25)
[Bmim]BF4(0.5)þ12 N HCl (0.25)
[Bmim]PF6 (0.5)þ12 N HCl (0.25)
[C2OHmim]Cl(0.5)þ12 N HCl (0.25)
[BuPy]Cl(0.5)þ12 N HCl (0.25)
H2O (0.5)þ12 N HCl (0.25)
DMSO (0.5)þ12 N HCl (0.25)
12 N HCl (0.25)
3
4d
5
On the basis of the optimized reaction conditions, we next ex-
amined the reuse of the palladium catalyst in [C2O2mim]Cl. The
results indicated that the catalyst was successfully recycled five
times with excellent yields. The reaction rate dropped significantly
at the fifth cycle, probably due to the decreased amount protons
and halide sources of ionic liquid. When 0.02 mL HCl solution was
added, the reaction gave the desired (Z)-3aa in 100% GC yield (Table
1, entries, 25, 26). However, it should be emphasized that the
present system realized five repetitions of the reaction without any
addition of the catalyst with excellent yield and good selectivity.
The catalyst solution could be stored for several days without de-
crease in the activity or regioselectivity.
6
7
8
9
d
87
83
93
88
93
93
93
95
94
98
89
90
98
100
100
100
98
83
100
100
78/22
63/37
95/5
10
11
12
13e
14f
15
16
17
18
19
20
21g
22h
23i
24j
25k
26l
94/6
61/39
61/39
71/29
77/23
98/2
98/2
98/2
98/2
98/2
>98/2
>98/2
>98/2
>98/2
>98/2
>98/2
>98/2
12 N HCl (0.25)
[C2O2mim]Cl (0.5)þH2O (0.1)
[C2O2mim]Cl (0.5)þH2O (0.25)
[C2O2mim]Cl (0.5)þH2O (0.5)
[C2O2mim]Cl (0.5)þH2O (0.25)
[C2O2mim]Cl (0.5)þH2O (0.25)
[C2O2mim]Cl (0.5)þHCl (0.25)
Second
Third
Fourth
Fifth
Sixth
With the optimized reaction conditions in hand, we further
investigated the scope and limitation of this reaction. The repre-
sentative results are summarized in Scheme 2. In most cases, the
allylation reactions proceeded smoothly and gave the desired (1Z)-
or (1E)-1-chloro-1,4-dienes in good to excellent yields with ex-
tremely high selectivity. What interesting is the substrate 3-
phenylpropiolic acid (1d) and oct-2-ynoic acid (1e), which resul-
ted in the introduction of a carboxylic acid moiety directly into the
1,4-diene without the need for functional group protection and
deprotection. Aliphatic alkynes also participated well in this re-
action, and resulted in the (1Z)-1-chloro-1,4-dienes in a highly se-
lectivity fashion and with good yields. For instance, the (Z)-methyl
2-(1-chloroethylidene) pent-4-enoate (3ac) and (Z)-2-allyl-3-
chlorooct-2-enoic acid (3ae) were generated in 78% and 93%
yields, respectively, and with excellent selectivity. The more chal-
lenging 4-phenylbut-3-yn-2-one (1f) and 3-phenylpropiolamide
(1g) showed good stability under the similar reaction conditions,
providing 3af and 3ag in 89% and 61% yield, respectively. It is
noteworthy that the terminal acetylenes (1hem) also gave the
desired 1,4-dienes rather than cotrimerization products in our
previous study.2f Finally, we also examined the steric effect for this
reaction. For example, the reaction of 1-ethynyl-4-methylbenzene
(1h) afforded 3ah in 81% yield, and 4-ethynyl-1,10-biphenyl (1j)
led to 3aj in 63% yield, which indicated a little steric effect on the
reaction. In sharp contrast, symmetric internal alkynes, such as 1,2-
diphenylethyne and 1,2-bis(4-methoxyphenyl)ethyne, failed to re-
act with 2a to afford the desired product under the standard re-
action conditions. Unfortunately, but-2-yne-1,4-diol also failed to
afford the desired product. Both electron-rich and electron-poor
phenylethynyl bromides were reacted with but-3-en-1-ol (2a) to
give the corresponding 1,4-diene products 3aqeas in good to ex-
cellent yields. Moreover, the reaction was found to be applicable to
chloroalkyne, although the reaction of chloroalkynes was relatively
Seventh
a
Reaction conditions: 1a (0.5 mmol), 2a (0.6 mmol), and PdCl2 were stirred in
different solvents.
b
Conversions analyzed by GC/MS are based on 1a.
The ratios of 1Z/1E.
The reaction was performed at 50 ꢀC.
With 4 equiv of NaCl.
With 4 equiv of LiCl.
The second run after entry 20, after extracted with ethyl ether.
The third run after entry 21, after extracted with ethyl ether.
The fourth run after entry 22, after extracted with ethyl ether.
The fifth run after entry 23, after extracted with ethyl ether.
The sixth run after entry 24, after extracted with ethyl ether, and HCl (0.02 mL)
c
d
e
f
g
h
i
j
k
was added.
l
The seventh run after entry 25, after extracted with ethyl ether, and HCl
(0.02 mL) was added.
As shown in Table 1, decreasing the amount of [Bmim]Cl only
resulted in slight decrease in the yields (entries 1 and 5) and de-
creasing the amount of HCl resulted in sharply decreased conver-
sion. It might mean that acidic medium favored this
transformation. And the reaction proceeded smoothly in the
0.25 mL HCl (entries 1e3, 6). The reaction was subsequently in-
vestigated in the replacement of [Bmim]Cl by other ionic liquids
(Fig.1), such as [Bmim]BF4, [Bmim]PF6, [C2OHmim]Cl, [BuPy]Cl, and
[C2O2mim]Cl (entries 7e10 and 15). Interestingly, the reaction still
gave the desired (Z)-3aa in 94% GC yield in [C2O2mim]Cl and H2O
without using HCl (entry 15). Furthermore, various the conven-
tional solvents were examined under the same reaction conditions,

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J. Li et al. / Tetrahedron 70 (2014) 1516e1523
sluggish (3ap). In terms of the selectivity, all the products obtained
in the presence of an excess of chloride ions and acid in a polar
solvent resulted from trans addition.2b,2c,7 The site of halogen ad-
dition to unsymmetric acetylenes was controlled by electronic
factors.8
a
Reaction conditions: 1t (0.5 mmol), 2 (0.6 mmol), PdCl2 (3 mol%),
[C2O2mim]Cl (0.5 mL) and HCl (0.25 mL) under the atmosphere of air at
room temperature. Yields referred to isolated yields. The ratios of 4Z/4E were
determined by NOE.
Scheme 3. PdCl2-catalyzed allylation of 1,4-dichloro- but-2-yne(1t) in [C2O2mim]Cl.
solvent of [C2O2mim]Br and HBr (Scheme 4). Fortunately, the bro-
moallylation of haloalkynes proceeded well. Alkynyl chlorides
whether possessing electron-donating groups or electron-
withdrawing groups on the benzene ring could undergo the
transformation in moderate yields (4a, 4b, and 4c). For bro-
moalkynes with a variety of substituted groups on the benzene
ring, including Me, Et, X, Ph, OEt, and even the bulky ethyl-
cyclohexyl group, the reaction could afford desired products in
moderate to good yields (4dem).
a
Reaction conditions: 1 (0.5 mmol), 2a (0.6 mmol), PdCl2 (3 mol%),
[C2O2mim]Cl (0.5 mL) and HCl (0.25 mL) under the atmosphere of air at
room temperature. Reaction was monitored by TLC for the completion of the
reaction. Yields referred to isolated yields.
b without HCl
Scheme 2. Pd(II)-catalyzed coupling reaction of alkynes with allyl alcohol in
[C2O2mim]Cl.
After the effect of alkynes had been examined, a series of sec-
ondary allyl alcohols was investigated in this transformation.
Generally, the reaction of allylic alcohols with a terminal CeC
double bond with 1,4-dichlorobut-2-yne (1t) produced the desired
products. For example, methyl, ethyl and pentyl allylic alcohols (2b,
2c, 2e) gave 1,4-dienes in good to excellent yields with mixture of E
and Z isomers (Scheme 3). Meanwhile, 2-methylbut-3-en-2-ol (2d)
afforded the product (Z)-3td in good yield. However, the allylic
alcohols with an internal CeC double bond failed to give the desired
products. For example, while crotyl alcohol, 3-methylbut-2-en-1-ol
and (E)-hept-2-en-1-ol with alkynes were performed under the
same reaction conditions, no 1,4-diene products were detected and
the alkynes were recovered after 24 h.
a
Reaction conditions: 1 (0.5 mmol), 2a (0.6 mmol), PdCl2 (3 mol%),
[C2O2mim]Br (0.5 mL) and HBr (0.25 mL) under the atmosphere of air at
room temperature. Reaction was monitored by TLC for the completion of the
reaction. Yields referred to isolated yields.
Scheme 4. Pd(II)-catalyzed cross-coupling reaction of haloalkynes with allyl alcohol in
[C2O2mim]Br.
After the chloroallylation of alkyne with allylic alcohols was
investigated thoroughly, we turned our attention to the bro-
moallylation of alkynes with allylic alcohols. Haloalkynes are one
kind of the most important intermediates and versatile building
blocks in organic synthesis.9 Very recently, they are widely used as
one of the coupling partners in transition- metal-catalyzed car-
bonecarbon (heteroatom) bond formations via cross-coupling re-
actions in our previous studies.10 Based on these results, we chose
haloalkynes as substrates to react with allyl alcohol in a mixed
In contract, when (bromoethynyl)benzene (1q) was allowed to
react with prop-2-en-1-ol (2a) in PdCl2e[C2O2mim]CleHBr system
under similar reaction condition, the reaction lost its regiospeci-
ficity, with the two mixed differentially halogenated 1,4-dienes 3aq
and 4a (Scheme 5).
Plausible Reaction Mechanism. In order to understand the re-
action mechanism of this unique transformation, several control
experiments were performed under the standard reaction condi-
tions (Scheme 6). The controlled experiment without alkyne was

J. Li et al. / Tetrahedron 70 (2014) 1516e1523
1519
Scheme 5. Contrast experiments.
performed, diallyl ether was observed in 87% GC yield and no allyl
chloride was obtained (Eq. 1). Furthermore, When ethyl 3-
phenylpropiolate (1a) was allowed to react with allyl chloride un-
der the standard conditions, however, product 3aa was detected
with only 5% GC yield and 1a almost completely recovered (Eq. 2).
Finally, employed 3-phenylpropiolic acid (1d) as the alkyne com-
ponent and trace desired product 3ad was detected by GCeMS and
allyl 3-phenylpropiolate 5 was obtained in 17% GC yield and 70% 1d
was recovered (Eq. 3). Therefore, these results suggested that the
reaction might not proceed via the allylic halide intermediate.
Scheme 7. A plausible reaction mechanism.
This process provides a new methodology for constructing 1,4-
dienes from alkynes and allylic alcohols.
4. Experimental section
4.1. General methods
€
Melting points were measured with a BUCHI B-545 melting
point instrument and were uncorrected. 1H and 13C NMR spectra
were recorded using a Bruker Avance 400 MHz NMR spectrometer.
The chemical shifts are referenced to signals at 7.26 and 77.0 ppm,
respectively, and chloroform is solvent with TMS as the internal
standard. Mass spectra were recorded on a Shimadzu GCeMS-
QP5050A spectrometer at an ionization voltage of 70 eV equipped
with a DB-WAX capillary column (internal diameter: 0.25 mm,
length: 30 m). Elemental analyses were performed with a Vario EL
elemental analyzer. IR spectra were obtained as potassium bromide
pellets or as liquid films between two potassium bromide pellets
with a Bruker Vector 22 spectrometer. High-resolution mass
spectra were obtained with Shimadazu LCMS-IT-TOF mass spec-
trometer. TLC was performed by using commercially prepared
100e400 mesh silica gel plates (GF254) and visualization was
effected at 254 nm. The ionic liquids ([Bmim]Cl,11 [Bmim]BF4,12
[Bmim]PF6,12 [C2OHmim]Cl,13 [BuPy]Cl,14 [C2O2mim]Cl,15 and
[C2O2mim]Br15) were synthesized using the procedure reported by
other authors. The bromoalkynes10 and chloroalkynes16 were pre-
pared according to the literature. Other reagents were purchased as
reagent grade and used without further purification.
Scheme 6. Control experiments.
On the basis of our previous reports and experimental data,2f,4
a plausible mechanism for the Pd-catalyzed haloallylation of al-
kynes with allylic alcohols in ionic liquids is illustrated in Scheme 7.
Pd-alkenyl intermediate
A is initially formed by trans-hal-
opalladation of the alkynes 1 in the presence of an excess of halide
ions in ionic liquids.4,7 Subsequently, intermediate A undergoes
alkene insertion to generate a Pd-alkyl intermediate B, which could
complex with ionic liquids ligand efficiently to inhibit b-hydride
elimination according to our previous report.4b With the aid of the
proton of HCl, which can protonize the hydroxyl group of the in-
termediate B, then the product 3 or 4 was formed through trans-b-
OH elimination of the intermediate B and the active Pd(II) specie
was regenerated. Here, the ionic liquid plays an important role in
the reaction. It not only acts as a solvent, but also provides the
excess halide ions to control the trans-halopalladation of the al-
kynes, and also to stabilize the intermediate B4b and inhibit the
b-
hydride elimination.
4.2. General procedure for the synthesis of 1,4-dienes
3. Conclusion
A mixture of alkynes 1 (0.5 mmol), 2 (0.6 mmol), palladium
chloride (3.2 mg, 3 mol %), ionic liquid (0.5 mL), HX (0.25 mL) in
a test tube (10 mL) equipped with a magnetic stirring bar. The
mixture was stirred under the atmosphere of air at room temper-
ature. After the reaction was completed, 10 mL ethyl acetate
(3ꢁ10 mL) was added into the tube. The combined organic layers
were washed with brine to neutral, dried over MgSO4, and con-
centrated in vacuum. Purification of the residue on a preparative
TLC afforded the desired products. Residual ionic liquid obtained
In summary, we have developed an efficient method for the
synthesis of 1,4-dienes by Pd(II)-catalyzed haloallylation of alkynes
with allyl alcohols via
termediates in the mixed solvent of ionic liquids and HCl. Both
chloroallylation and bromoallylation can be easily carried out with
high selectivity in moderate to excellent yields. Moreover, the Pd
catalyst as well as the ionic liquid can be recycled several times.
b-OH elimination of alkylpalladium in-

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J. Li et al. / Tetrahedron 70 (2014) 1516e1523
after the workup was stirred with diethyl ether (2ꢁ10 mL) for
15 min, and the ethereal layer was decanted. The ionic liquid was
then directly used for the next runs without further dry and reused
for up to five runs.
0.8 Hz, 1H), 3.07 (d, J¼7.2 Hz, 2H); 13C NMR (100 MHz, CDCl3)
d
167.5, 137.1, 133.9, 130.7, 129.3, 128.5, 117.4, 36.5 ppm; MS (EI) m/z
115, 128, 141, 143, 168, 184, 186, 221; HRMS(EI) calcd for C12H12ClNO
221.0607, found 221.0603.
4.2.1. (Z)-Ethyl 2-(chloro(phenyl)methylene)pent-4-enoate
4.2.8. (E)-1-(1-Chloropenta-1,4-dien-1-yl)-4-methylbenzene
(3aa). Yield: 89% (111.3 mg) as a yellow oil; IR (KBr) v 3074,
(3ah). Yield: 81% (77.8 mg) as a yellow oil; IR (KBr) v 3077, 2924,
2983, 2930, 1725, 1637, 1485, 1443, 706 cmꢂ1
;
1H NMR (400 MHz,
1694, 1511, 1432, 728 cmꢂ1; 1H NMR (400 MHz, CDCl3)
d 7.23e7.17
CDCl3)
d
7.40e7.36 (m, 5H), 5.82e5.72 (m, 1H), 5.11 (dd, J¼8.4,
(m, 4H), 6.11 (s, 1H), 5.81e5.71 (m, 1H), 5.07 (dd, J¼8.0, 1.2 Hz, 1H),
0.8 Hz, 1H), 5.07 (dd, J¼10.8, 0.8 Hz, 1H), 4.32 (q, J¼7.1 Hz, 2H), 3.05
5.04 (dd, J¼9.2, 1.2 Hz, 1H), 3.14 (d, J¼6.4 Hz, 2H), 2.36 (s, 3H); 13
C
(d, J¼6.0 Hz, 2H), 1.35 (t, J¼7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3)
NMR (100 MHz, CDCl3) d 140.9,137.4, 134.8, 134.7, 128.9,128.1, 117.3,
114.1, 45.1, 21.3 ppm; MS (EI) m/z 77, 91, 115, 129, 142, 157, 192;
d
167.5, 137.2, 133.9, 133.4, 130.8, 129.3, 128.4, 117.2, 61.3, 36.2,
14.2 ppm; MS (EI) m/z: 115, 128, 141, 177, 205, 250; HRMS(ESI) calcd
for C14H15ClO2Na (MþþNa) 273.0653, found 273.0655.
HRMS(EI) calcd for C12H13Cl 192.0706, found 192.0703.
4.2.9. (E)-1-(1-Chloropenta-1,4-dien-1-yl)-4-ethylbenzene
4.2.2. (Z)-Methyl 2-(chloro(phenyl)methylene)pent-4-enoate
(3ai). Yield: 76% (78.3 mg) as a yellow oil; IR (KBr) v 3078, 2965,
(3ab). Yield: 93% (109.7 mg) as a yellow oil; IR (KBr) v 3078,
2928, 1726, 1692, 1457, 750 cmꢂ1 1H NMR (400 MHz, CDCl3)
;
2951, 2907, 1731, 1638, 1489, 1436, 705 cmꢂ1
;
1H NMR (400 MHz
d
7.25e7.20 (m, 4H), 6.11 (s, 1H), 5.82e5.72 (m, 1H), 5.08 (dd, J¼6.4,
CDCl3):
d
7.40e7.34 (m, 5H), 5.81e5.71 (m, 1H), 5.10 (dd, J¼4.8,
1.2 Hz, 1H), 5.04 (dd, J¼8.8, 1.2 Hz, 1H), 3.15 (d, J¼6.8 Hz, 2H), 2.66
0.8 Hz, 1H), 5.07 (dd, J¼5.2, 0.8 Hz, 1H), 3.84 (s, 3H), 3.04 (d,
(q, J¼7.6 Hz, 2H), 1.25 (t, J¼6.8 Hz, 3H); 13C NMR (100 MHz, CDCl3)
J¼6.0 Hz, 2H); 13C NMR (100 MHz, CDCl3):
d
167.9, 137.1, 133.9,
d 143.7, 140.9, 135.0, 134.7, 128.1, 127.7, 117.3, 114.1, 41.5, 28.6,
133.8, 130.6, 129.3, 128.4, 128.3, 117.2, 52.1, 36.2 ppm; MS (EI) m/z
115, 129, 141, 177, 201, 236; HRMS(ESI) calcd for C13H14ClO2 (MþþH)
237.0677, found 237.0678.
15.3 ppm; MS (EI) m/z 115, 128, 141, 143, 155, 171, 177, 206;
HRMS(EI) calcd for C13H15Cl 206.0862, found 206.0860.
4.2.10. (E)-4-(1-Chloropenta-1,4-dien-1-yl)-1,10-biphenyl
4.2.3. (Z)-Ethyl 2-(1-chloroethylidene)pent-4-enoate (3ac). Yield:
78% (73.3 mg) as a yellow oil; IR (KBr) v 2921, 2851, 1632, 1369,
(3aj). Yield: 63% (80.1 mg) as a yellow solid; mp¼137.3e138.1 ꢀC;
IR (KBr) v 3064, 2925, 1687, 1602, 1517, 1449, 756 cmꢂ1 1H NMR
;
704 cmꢂ1; 1H NMR (400 MHz, CDCl3)
d
5.81e5.71 (m, 1H), 5.10 (dd,
(400 MHz, CDCl3) d 7.62e7.59 (m, 4H), 7.46e7.40 (m, 4H), 7.36e7.33
J¼8.8,1.2 Hz,1H), 5.05 (dd, J¼15.6,1.2 Hz,1H), 4.25 (q, J¼7.2 Hz, 2H),
(m, 1H), 6.17 (s, 1H), 5.85e5.75 (m, 1H), 5.11 (dd, J¼6.8, 0.8 Hz, 1H),
3.08 (d, J¼6.0 Hz, 2H), 2.18 (s, 3H), 1.31 (t, J¼6.8 Hz, 3H); 13C NMR
5.07 (dd, J¼16.0, 0.8 Hz, 1H), 3.20 (d, J¼6.8 Hz, 2H); 13C NMR
(100 MHz, CDCl3)
d
167.4, 133.4, 133.3, 128.5, 116.7, 61.0, 34.9, 23.1,
(100 MHz, CDCl3) d 140.7, 140.6, 140.5, 136.7, 134.6, 128.8, 128.7,
14.1 ppm; MS (EI) m/z 77, 79, 107, 115, 143, 153, 188; HRMS(ESI)
127.4, 127.1, 126.8, 117.5, 114.6, 41.4 ppm; MS (EI) m/z 73, 77, 91, 115,
141, 152, 165, 178, 191, 203, 219, 254; HRMS(EI) calcd for C17H15Cl
254.0862, found 254.0858.
calcd for C9H13ClO2Na (MþþNa) 211.0496, found 211.0493.
4.2.4. (Z)-2-(Chloro(phenyl)methylene)pent-4-enoic
(3ad). Yield: 87% (96.6 mg) as a yellow oil; IR (KBr) v 3075, 2923,
1699, 1641, 1489, 1413, 701 cmꢂ1 1H NMR (400 MHz, CDCl3)
acid
4.2.11. (E)-1-Chloro-4-(1-chloropenta-1,4-dien-1-yl)benzene
;
(3ak). Yield: 83% (87.9 mg) as a yellow oil; IR (KBr) v 3086, 2924,
d
7.44e7.36 (m, 5H), 5.88e5.78 (m, 1H), 5.10 (dd, J¼4.8, 1.2 Hz, 1H),
1682, 1589, 1488, 720 cmꢂ1; 1H NMR (400 MHz, CDCl3)
d 7.35e7.31
5.07 (dd, J¼6.0, 1.2 Hz, 1H), 3.09 (d, J¼6.0 Hz, 2H); 13C NMR
(m, 4H), 6.01 (t, J¼8.0 Hz, 1H), 5.85e5.75 (m, 1H), 5.09 (dd, J¼8.8,
(100 MHz, CDCl3)
d 172.6, 137.4, 136.9, 133.9, 129.5, 129.3, 128.5,
1.2 Hz, 1H), 5.06 (dd, J¼9.2, 1.2 Hz, 1H), 2.81 (dt, J¼6.4, 1.2 Hz, 2H);
128.2, 117.2, 36.1 ppm; MS (EI) m/z 115, 141, 142, 143, 177, 222;
13C NMR (100 MHz, CDCl3)
d 135.4, 135.2, 134.6, 130.5, 130.0, 128.5,
HRMS(ESI) calcd for C12H10ClO2 (MꢂꢂH) 221.0375, found 221.0377.
127.7, 116.0, 33.7 ppm; MS (EI) m/z 115, 142, 177, 212; HRMS(EI)
calcd for C11H10Cl2 212.0160, found 212.0158.
4.2.5. (Z)-2-Allyl-3-chlorooct-2-enoic acid (3ae). Yield: 93%
(100.4 mg) as a yellow oil; IR (KBr) v 3082, 2930, 1698, 1642,
4.2.12. (E)-((2-Chlorohexa-2,5-dien-1-yl)oxy)benzene (3al). Yield:
75% (78.1 mg)as a yellow oil; IR (KBr) v 3075, 2926, 1640, 1493,
752 cmꢂ1; 1H NMR (400 MHz, CDCl3)
d 5.85e5.75 (m, 1H), 5.12 (dd,
J¼10.0, 1.2 Hz, 1H), 5.08 (dd, J¼16.4, 1.2 Hz, 1H), 3.14 (d, J¼6.0 Hz,
753 cmꢂ1 1H NMR (400 MHz, CDCl3)
; d 7.29e7.26 (m, 2H),
2H), 2.45 (t, J¼7.6 Hz, 2H), 1.66e1.59 (m, 2H), 1.36e1.26 (m, 4H),
6.97e6.92 (m, 3H), 6.03 (s, 1H), 5.84e5.74 (m, 1H), 5.12 (dd, J¼8.8,
0.906 (t, J¼6.8 Hz, 3H); 13C NMR (100 MHz, CDCl3)
d 172.5, 141.9,
1.2 Hz, 1H), 5.09 (dd, J¼10.4, 1.2 Hz, 1H), 4.73 (s, 2H), 2.95 (d,
133.7, 126.8, 116.7, 36.5, 34.5, 31.1, 27.1, 22.4, 13.9 ppm; HRMS(ESI)
J¼6.8 Hz, 2H); 13C NMR (100 MHz, CDCl3)
d 158.4,137.3,134.2,129.6,
calcd for C11H18ClO2 (MꢂꢂH) 215.0844, found 215.0845.
121.1, 117.8, 116.3, 114.7, 64.7, 36.6 ppm; MS (EI) m/z 79, 94, 157, 173,
208; HRMS(ESI) calcd for C12H13ClONa (MþþNa) 231.0547, found
231.0550.
4.2.6. (Z)-3-(Chloro(phenyl)methylene)hex-5-en-2-one (3af). Yield:
77% (84.7 mg) as a colorless oil; IR (KBr) v 3081, 2936, 1694, 1645,
770 cmꢂ1
;
1H NMR (400 MHz, CDCl3)
d
7.41e7.37 (m, 5H),
4.2.13. (E)-(2-Chlorohexa-2,5-dien-1-yl)(phenyl)sulfane
5.80e5.70 (m, 1H), 5.10 (dd, J¼10.4, 1.6 Hz, 1H), 5.07 (dd, J¼16.0,
(3am). Yield: 37% (41.4 mg) as a yellow oil; IR (KBr) v 3063, 2923,
1.2 Hz, 1H), 3.02 (d, J¼6.0 Hz, 2H), 2.50 (s, 3H); 13C NMR (100 MHz,
1580, 1477, 741 cmꢂ1 1H NMR (400 MHz, CDCl3)
; d 7.40e7.34 (m,
CDCl3)
d
203.5, 138.6, 137.0, 133.8, 130.4, 129.3, 128.9, 128.4, 117.5,
4H), 7.29e7.27 (m, 1H), 7.22e7.19 (m, 1H), 6.08 (s, 1H), 5.95 (dd,
J¼6.4, 0.8 Hz, 1H), 5.89 (dd, J¼9.2, 0.8 Hz, 1H), 3.83 (s, 2H), 3.57 (d,
36.5, 31.0 ppm; MS (EI) m/z 115, 128, 141, 143, 163, 183, 185, 205,
220; HRMS(EI) calcd for C13H13ClO 220.0655, found 220.0647.
J¼2.8 Hz, 2H); 13C NMR (100 MHz, CDCl3)
d 136.2,135.6,131.5,130.8,
129.6, 128.9, 128.8, 127.1, 126.7, 121.2, 37.1, 31.6 ppm; MS (EI) m/z
110, 135, 147, 186, 207, 224; HRMS(ESI) calcd for C12H14ClS (MþþH)
225.0499, found 225.0502.
4.2.7. (Z)-2-(Chloro(phenyl)methylene)pent-4-enamide
(3ag).2l Yield: 61% (67.4 mg) as a white solid.; mp¼163.4e164.7 ꢀC;
IR (KBr) v 3074, 2983, 2930, 1725, 1637, 1485, 1443, 706 cmꢂ1 1H
;
NMR (400 MHz, CDCl3)
d
7.42e7.37 (m, 5H), 6.02 (s,1H), 5.96 (s,1H),
4.2.14. (E)-(1-Chloro-2-methylpenta-1,4-dien-1-yl)benzene
5.85e5.75 (m, 1H), 5.10 (dd, J¼10.0, 1.2 Hz, 1H), 5.08 (dd, J¼10.8,
(3an). Yield: 83% (79.7 mg) as a yellow oil; IR (KBr) v 3064, 2926,

J. Li et al. / Tetrahedron 70 (2014) 1516e1523
1521
1722, 1599, 1490, 1447, 703 cmꢂ1
;
1H NMR (400 MHz, CDCl3)
(95.4 mg) as a yellow oil; IR (KBr) v 3023, 2926, 1637, 1443,
714 cmꢂ1 1H NMR (400 MHz, CDCl3)
5.70e5.52 (m, 1H),
d
7.36e7.27 (m, 5H), 5.80e5.70 (m, 1H), 5.06 (dd, J¼8.4, 1.2 Hz, 1H),
;
d
5.00 (dd, J¼10.8, 1.2 Hz, 1H), 2.78 (d, J¼6.0 Hz, 2H), 1.98 (s, 3H); 13
C
5.41e5.28 (m, 1H), 4.31 (d, J¼6.8 Hz, 2H), 4.23 (s, 2H), 3.12 (d,
NMR (100 MHz, CDCl3)
d 139.1, 135.3, 132.2, 128.9, 128.2, 128.0,
J¼7.6 Hz, 0.85H), 3.03 (d, J¼6.4 Hz, 1.15H), 1.73e1.68 (m, 3H); 13C
127.4, 116.5, 39.6, 19.7 ppm; MS (EI) m/z 51, 77, 91, 115, 129, 142, 157,
NMR (100 MHz, CDCl3) d 136.8, 136.3, 129.9, 129.7, 128.9, 127.6,
177, 192; HRMS(EI) calcd for C12H13Cl 192.0706, found 192.0703.
125.7, 125.0, 45.0, 44.9, 43.7, 43.6, 33.7, 28.4, 17.9, 12.9 ppm; MS (EI)
m/z 91, 105, 141, 143, 177, 212; HRMS(EI) calcd for C8H11Cl3 211.9926
found 211.9923.
4.2.15. (E)-(1-Chloro-2-ethylpenta-1,4-dien-1-yl)benzene
(3ao). Yield: 83% (85.5 mg) as a yellow oil; IR (KBr) v 3079, 2968,
1641, 1457, 755/cmꢂ1
;
1H NMR (400 MHz, CDCl3)
d
7.35e7.31 (m,
4.2.22. [(Z)-1,2-Dichloro-3-(chloromethyl)octa-2,5-diene:(E)-1,2-
dichloro-3-(chloromethyl)octa-2,5-diene¼1:1.5] (3ct). Yield: 93%
(105.1 mg) as a yellow oil; IR (KBr) v 3017, 2931, 1636, 1443,
2H), 7.23e7.19 (m, 3H), 5.77e5.67 (m, 1H), 5.04 (dd, J¼10.8, 1.2 Hz,
1H), 5.00 (dd, J¼16.0, 1.2 Hz, 1H), 3.17 (d, J¼6.4 Hz, 2H), 2.55 (q,
J¼7.2 Hz, 2H), 1.22 (t, J¼7.6 Hz, 3H); 13C NMR (100 MHz, CDCl3)
715 cmꢂ1
; d 5.63e5.53 (m, 1H),
1H NMR (400 MHz, CDCl3)
d
141.6, 134.6, 133.8, 133.7, 128.6, 127.9, 126.9, 116.1, 39.1, 29.1,
5.38e5.21 (m, 1H), 4.31 (d, J¼4.8 Hz, 2H), 4.23 (s, 2H), 3.11 (d,
J¼7.2 Hz, 0.8H), 3.04 (d, J¼6.4 Hz, 1.2H), 2.18e2.11 (m, 0.8H),
2.07e2.00 (m, 1.2H), 1.03e0.96 (m, 3H); 13C NMR (100 MHz, CDCl3)
12.8 ppm; MS (EI) m/z 77, 91, 115, 129, 141, 143, 177, 179, 206;
HRMS(EI) calcd for C13H15Cl 206.0862, found 206.0858.
d
136.8,136.4,135.9, 135.3, 129.9,129.7, 123.5, 123.4, 44.9, 43.6, 33.8,
4.2.16. (Z)-(1,2-Dichloropenta-1,4-dien-1-yl)benzene (3ap).2j Yield:
79% (83.7 mg) as a yellow oil; IR (KBr) v 3075, 2924, 1625, 1488,
28.7, 25.5, 20.7, 14.1, 13.5 ppm; MS (EI) m/z 91, 119, 155, 184, 193,
226; HRMS(EI) calcd for C9H13Cl3 226.0083 found 226.0081.
1429, 742 cmꢂ1 1H NMR (400 MHz, CDCl3)
; d 7.38e7.33 (m, 5H),
5.88e5.78 (m, 1H), 5.17 (dd, J¼10.2, 1.2 Hz, 1H), 5.12 (dd, J¼17.2,
4.2.23. (Z)-1,2-Dichloro-3-(chloromethyl)-6-methylhepta-2,5-diene
1.2 Hz, 1H), 3.11 (d, J¼6.0 Hz, 2H); 13C NMR (100 MHz, CDCl3)
(3dt). Yield: 87% (98.3 mg) as a yellow oil; IR (KBr) v 3027, 2923,
d
136.9, 133.2, 131.2, 129.4, 129.1, 128.7, 128.5, 117.8, 40.6 ppm; MS
1635, 1442, 714 cmꢂ1 1H NMR (400 MHz, CDCl3)
; d 5.05e5.02 (m,
(EI) m/z 115, 141, 142, 162, 177, 197, 212; HRMS(EI) calcd for
11H10Cl2 212.0160, found 212.0157.
1H), 4.32 (s, 2H), 4.22 (s, 2H), 3.06 (d, J¼7.2 Hz, 2H), 1.72 (d,
C
J¼5.6 Hz, 6H); 13C NMR (100 MHz, CDCl3)
d 137.3, 135.6,129.3,119.2,
45.0, 43.7, 29.6, 25.7, 17.9 ppm; MS (EI) m/z 119, 191, 193, 226;
4.2.17. (Z)-(2-Bromo-1-chloropenta-1,4-dien-1-Yl)benzene
HRMS(EI) calcd for C9H13Cl3 226.0083 found 226.0082.
(3aq).2j Yield: 93% (118.9 mg) as a yellow oil; IR (KBr) v 3074, 2980,
1637, 1490, 716 cmꢂ1
;
1H NMR (400 MHz, CDCl3)
d
7.37e7.32 (m,
4.2.24. [(Z)-1,2-Dichloro-3-(chloromethyl)undeca-2,5-diene:(E)-1,2-
dichloro-3-(chloromethyl) undeca-2,5-diene¼1:1] (3et). Yield: 89%
(119.3 mg) as a yellow oil; IR (KBr) v 3015, 2927, 1636, 1448,
5H), 5.87e5.77 (m, 1H), 5.16 (dd, J¼10.2,1.2 Hz,1H), 5.11 (dd, J¼17.2,
1.2 Hz, 1H), 3.19 (d, J¼4.8 Hz, 2H); 13C NMR (100 MHz, CDCl3)
d
137.2, 133.8, 132.3, 129.1, 128.6, 128.5, 124.1, 117.7, 42.6 ppm; MS
716 cmꢂ1 1H NMR (400 MHz, CDCl3)
; d 5.61e5.51 (m, 1H),
(EI) m/z 115, 142, 177, 256; HRMS(EI) calcd for C11H10ClBr 255.9654,
found 255.9650.
5.38e5.24 (m, 1H), 4.31 (d, J¼4.8 Hz, 2H), 4.23 (s, 2H), 3.16 (d,
J¼7.2 Hz, 1H), 3.04 (d, J¼6.8 Hz, 1H), 2.12 (q, J¼7.2 Hz, 1H), 2.01
(q, J¼7.2 Hz, 1H), 1.43e1.24 (m, 6H), 0.92e0.87 (m, 3H); 13C NMR
4.2.18. (Z)-1-(2-Bromo-1-chloropenta-1,4-dien-1-yl)-4-ethylbenzene
(100 MHz, CDCl3) d 136.8, 136.4, 134.6, 133.8, 129.9, 129.6, 124.3,
(3ar). Yield: 94% (133.5 mg) as a yellow oil; IR (KBr) v 3072, 2981,
123.9, 45.0, 44.9, 43.6, 33.8, 32.4, 31.5, 31.4, 29.2, 28.9, 28.7, 27.3,
22.5, 22.4, 14.0 ppm; MS (EI) m/z 67, 77, 91, 113, 127, 149, 163, 184,
1635, 1450, 726 cmꢂ1; 1H NMR (400 MHz, CDCl3)
d
7.27 (d, J¼8.0 Hz,
2H), 7.19 (d, J¼8.0 Hz, 2H), 5.88e5.78 (m,1H), 5.17 (dd, J¼10.2,1.2 Hz,
198, 268; HRMS(EI) calcd for
268.0549.
C12H19Cl3 268.0552, found
1H), 5.13 (dd, J¼16.8, 1.2 Hz, 1H), 3.22 (d, J¼4.8 Hz, 2H), 2.69e2.63
(m, 2H), 1.24 (t, J¼7.6 Hz, 3H); 13C NMR (100 MHz, CDCl3)
d 145.4,
134.5, 133.9, 132.5, 128.5, 128.0, 123.6, 117.6, 42.6, 28.7, 15.3 ppm; MS
(EI) m/z 115, 128, 141, 155, 169, 176, 190, 205, 207, 249, 257, 271, 284;
HRMS(EI) calcd for C13H14ClBr 283.9967, found 283.9962.
4.2.25. (Z)-(1-Bromo-2-chloropenta-1,4-dien-1-yl)benzene
(4a). Yield: 81% (103.7 mg) as a yellow oil; IR (KBr) v 3077, 2924,
1610, 1489, 1438, 735 cmꢂ1; 1H NMR (400 MHz, CDCl3)
d 7.38e7.32
(m, 5H), 5.87e5.77 (m, 1H), 5.15 (d, J¼10.0 Hz, 1H), 5.10 (d,
4.2.19. (Z)-1-(2-Bromo-1-chloropenta-1,4-dien-1-yl)-4-nitrobenzene
J¼16.8 Hz, 1H), 3.08 (d, J¼6.4 Hz, 2H); 13C NMR (100 MHz, CDCl3)
(3as). Yield: 63% (94.8 mg) as a yellow oil; IR (KBr) v 3071, 2982,
d 138.8, 133.9, 133.0, 128.9, 128.8, 128.5, 120.5, 117.8, 40.8 ppm; MS
(EI) m/z 115, 141, 162, 177, 223, 256; HRMS(EI) calcd for C11H10ClBr
1635, 1490, 724 cmꢂ1
;
1H NMR (400 MHz, CDCl3)
d
8.26e8.18 (m,
2H), 7.63e7.55 (m, 2H), 5.89e5.79 (m, 1H), 5.23 (dd, J¼10.2, 1.2 Hz,
255.9654, found 255.9652.
1H), 5.14 (dd, J¼17.2, 1.2 Hz, 1H), 3.21 (d, J¼6.0 Hz, 2H); 13C NMR
(100 MHz, CDCl3)
d
147.9, 143.3, 132.8, 129.7, 126.3, 123.8, 123.6,
4.2.26. (Z)-1-(1-Bromo-2-chloropenta-1,4-dien-1-yl)-4-
118.1, 42.6 ppm; MS (EI) m/z 115, 141, 149, 157, 176, 178, 205, 222,
224, 266, 301; HRMS(EI) calcd for C11H9ClBr NO2 300.9505, found
300.9497.
methylbenzene (4b). Yield: 81% (109.4 mg) as a yellow oil; IR (KBr) v
3081, 2924, 1641, 1458, 747 cmꢂ1 1H NMR (400 MHz, CDCl3)
;
d
7.24e7.12 (m, 4H), 5.87e5.77 (m, 1H), 5.14 (dd, J¼10.0, 1.2 Hz, 1H),
5.10 (dd, J¼17.2, 1.2 Hz, 1H), 3.08 (dt, J¼6.4, 1.6 Hz, 2H), 2.36 (s, 3H);
13C NMR (100 MHz, CDCl3)
139.0, 135.9, 133.6, 133.1, 129.2, 128.7,
4.2.20. (Z)-5,6-Dichloro-4-(chloromethyl)hexa-1,4-diene
d
(3at). Yield: 98% (97.1 mg) as a yellow oil; IR (KBr) v 3088, 2928,
120.7, 117.7, 40.9, 21.3 ppm; MS (EI) m/z 115, 142, 177, 197, 270;
HRMS(EI) calcd for C12H12ClBr 269.9811, found 269.9808.
1523, 1272, 719 cmꢂ1
;
1H NMR (400 MHz, CDCl3)
d
5.83e5.73 (m,
1H), 5.17 (dd, J¼3.2, 1.2 Hz, 1H), 5.13 (dd, J¼10.2, 2.8 Hz, 1H), 4.29 (s,
2H), 4.25 (s, 2H), 3.12 (dt, J¼6.4, 1.2 Hz, 2H); 13C NMR (100 MHz,
4.2.27. (Z)-1-(1-Bromo-2-chloropenta-1,4-dien-1-yl)-4-
CDCl3)
d
135.4, 133.1, 130.5, 117.9, 44.9, 43.6, 34.8 ppm; MS (EI) m/z
methoxybenzene (4c). Yield: 78% (111.5 mg) as a yellow oil; IR (KBr)
77, 91, 127, 129, 163, 165, 198; HRMS(EI) calcd for C7H9Cl3 197.9770,
found 197.9766.
v 3079, 2925, 1640, 1460, 746 cmꢂ1 1H NMR (400 MHz, CDCl3)
;
d
7.25e7.24 (m, 2H), 6.89e6.86 (m, 2H), 5.88e5.78 (m, 1H), 5.15 (dd,
J¼10.4, 1.2 Hz, 1H), 5.10 (dd, J¼17.2, 1.6 Hz, 1H), 3.82 (s, 3H), 3.08 (dt,
4.2.21. (Z)-1,2-Dichloro-3-(chloromethyl)hepta-2,5-diene:(E)-1,2-
dichloro-3-(chloromethyl) hepta-2,5-diene¼1:1.4] (3bt). Yield: 90%
J¼6.0, 1.6 Hz, 2H); 13C NMR (100 MHz, CDCl3)
d 159.9, 133.5, 133.2,
131.1, 130.2, 120.7, 117.7, 113.8, 55.4, 40.9 ppm; MS (EI) m/z 75, 102,

1522
J. Li et al. / Tetrahedron 70 (2014) 1516e1523
128, 141, 157, 171, 207, 286; HRMS(EI) calcd for C12H12OClBr
285.9760, found 285.9756.
2H), 7.08e7.02 (m, 2H), 5.86e5.76 (m, 1H), 5.16 (dd, J¼10.0, 1.2 Hz,
1H), 5.10 (dd, J¼17.2, 1.2 Hz, 1H), 3.16 (t, J¼6.0 Hz, 2H); 13C NMR
(100 MHz, CDCl3)
d
162.7 (J¼248.2 Hz),135.2 (J¼3.4 Hz),133.4,130.5
4.2.28. (Z)-(1,2-Dibromopenta-1,4-dien-1-yl)benzene (4d).2k Yield:
87% (130.5 mg) as a yellow oil; IR (KBr) v 3082, 2923, 1645, 1450,
(J¼8.2 Hz),127.7,122.7,117.7,115.6 (J¼21.7 Hz), 43.0 ppm; MS (EI) m/
z 106, 133, 160, 180, 197, 224, 318; HRMS(EI) calcd for C11H9Br2F
317.9055, found 317.9053.
743 cmꢂ1
; d 7.37e7.31 (m, 5H),
1H NMR (400 MHz, CDCl3)
5.85e5.75 (m, 1H), 5.15 (dd, J¼10.4, 1.2 Hz, 1H), 5.09 (dd, J¼17.2,
1.2 Hz, 1H), 3.16 (d, J¼6.0, 1.6 Hz, 2H); 13C NMR (100 MHz, CDCl3)
4.2.35. (Z)-1-Chloro-4-(1,2-dibromopenta-1,4-dien-1-yl)benzene
d
139.2, 133.7, 128.9, 128.6, 127.2, 123.8, 117.7, 43.0 ppm; MS (EI) m/z
(4k). Yield: 87% (145.3 mg) as a yellow oil; IR (KBr) v 3080, 2920,
115, 142, 180, 193, 226, 228, 285, 287, 289, 300; HRMS(EI) calcd for
11H10Br2 299.9149, found 299.9147.
1641, 1486, 745 cmꢂ1 1H NMR (400 MHz, CDCl3)
; d 7.36e7.33 (m,
C
2H), 7.27e7.26 (m, 2H), 5.85e5.75 (m, 1H), 5.17 (dd, J¼9.6, 0.8 Hz,
1H), 5.09 (dd, J¼16.4, 0.8 Hz,1H), 3.17 (d, J¼6.4,1.2 Hz, 2H); 13C NMR
4.2.29. (Z)-1-(1,2-Dibromopenta-1,4-dien-1-yl)-4-methylbenzene
(100 MHz, CDCl3) d 137.6, 134.9, 133.4, 129.9, 128.8, 127.8, 122.4,
(4e). Yield: 91% (142.8 mg) as a yellow oil; IR (KBr) v 3079, 2921,
117.8, 43.0 ppm; MS (EI) m/z 113, 115, 141, 176, 257, 334; HRMS(EI)
calcd for C11H9ClBr2 333.8760, found 333.8757.
1641, 1506, 781 cmꢂ1
;
1H NMR (400 MHz, CDCl3)
d
7.22e7.15 (m,
4H), 5.86e5.76 (m,1H), 5.15 (dd, J¼10.4,1.2 Hz,1H), 5.09 (dd, J¼17.2,
1.2 Hz, 1H), 3.17 (d, J¼6.0 Hz, 2H), 2.36 (s, 3H); 13C NMR (100 MHz,
4.2.36. (Z)-1-Chloro-2-(1,2-dibromopenta-1,4-dien-1-yl)benzene
CDCl3)
d
138.9, 136.3, 133.8, 129.2, 128.4, 126.8, 124.1, 117.6, 43.0,
(4l). Yield: 80% (133.5 mg) as a yellow oil; IR (KBr) v 3077, 2921,
21.3 ppm; MS (EI) m/z 115, 128, 141, 156, 160, 234, 238, 314;
1640, 1469, 749 cmꢂ1 1H NMR (400 MHz, CDCl3)
; d 7.33e7.27 (m,
HRMS(EI) calcd for C12H12Br2 313.9306, found 313.9303.
3H), 7.22e7.20 (m, 1H), 5.85e5.75 (m, 1H), 5.17 (dd, J¼10.0, 1.2 Hz,
1H), 5.10 (dd, J¼17.2, 1.2 Hz, 1H), 3.16 (d, J¼6.4, 1.2 Hz, 2H); 13C NMR
4.2.30. (Z)-1-(1,2-Dibromopenta-1,4-dien-1-yl)-4-ethylbenzene
(100 MHz, CDCl3) d 140.7, 134.3, 133.3, 129.8, 129.1128.7, 128.2,
(4f). Yield: 88% (144.3 mg) as a yellow oil; IR (KBr) v 3079, 2967,
126.8, 121.9, 117.9, 43.1 ppm; MS (EI) m/z 113, 115, 141, 176, 222, 257,
334; HRMS(EI) calcd for C11H9ClBr2 333.8760, found 333.8757.
1602, 1456, 761 cmꢂ1
;
1H NMR (400 MHz, CDCl3)
d
7.24e7.18 (m,
4H), 5.87e5.77 (m, 1H), 5.16 (dd, J¼10.4, 1.2 Hz, 1H), 5.12 (dd,
J¼16.4, 1.2 Hz, 1H), 3.18 (d, J¼4.8 Hz, 2H), 2.69e2.63 (m, 2H), 1.25 (t,
4.2.37. (Z)-1-Bromo-4-(1,2-dibromopenta-1,4-dien-1-yl)benzene
J¼7.6 Hz, 3H); 13C NMR (100 MHz, CDCl3)
d
145.2, 136.5, 133.8,
(4m). Yield: 74% (139.8 mg) as a yellow oil; IR (KBr) v 3080, 2923,
128.5, 127.9, 126.8, 124.2, 117.6, 43.1, 28.7, 15.3 ppm; MS (EI) m/z 115,
128, 141, 155, 170, 328; HRMS(EI) calcd for C13H14Br2 327.9462,
found 327.9460.
1641, 1483, 739 cmꢂ1 1H NMR (400 MHz, CDCl3)
; d 7.51e7.47 (m,
2H), 7.22e7.19 (m, 2H), 5.85e5.75 (m, 1H), 5.16 (dd, J¼10.0, 1.2 Hz,
1H), 5.09 (dd, J¼17.2, 1.2 Hz, 1H), 3.15 (d, J¼6.0 Hz, 2H); 13C NMR
(100 MHz, CDCl3)
d 138.0, 133.4, 131.8, 130.2, 127.8, 123.2, 122.5,
4.2.31. (Z)-4-(1,2-Dibromopenta-1,4-dien-1-yl)-1,10-biphenyl
117.8, 43.0 ppm; MS (EI) m/z 115, 141, 220, 222, 378; HRMS(EI) calcd
for C11H9Br3 377.8254, found 377.8251.
(4g). Yield: 73% (137.2 mg) as a yellow solid; mp¼157.5e158.7 ꢀC;
IR (KBr) v 3080, 2921, 1640, 1504, 750 cmꢂ1 1H NMR (400 MHz,
;
CDCl3)
d
7.59e7.56 (m, 4H), 7.45e7.33 (m, 5H), 5.88e5.78 (m, 1H),
Acknowledgements
5.17 (dd, J¼10.0, 1.2 Hz, 1H), 5.12 (dd, J¼17.2, 1.2 Hz, 1H), 3.22 (d,
J¼6.0 Hz, 2H); 13C NMR (100 MHz, CDCl3)
d
141.8, 140.1, 138.0, 133.7,
The authors are grateful to the National Natural Science Foun-
dation of China (21102047 and 20932002), National Basic Research
Program of China (973 Program) (2011CB808600), China Post-
doctoral Science Foundation (2012T50673) and the Fundamental
Research Funds for the Central Universities (2012ZM0037 and
2012ZB0011) for financial support.
129.0, 128.9, 127.8, 127.3, 127.2, 127.1, 43.1 ppm; MS (EI) m/z 109,
165, 189, 202, 218, 376; HRMS(EI) calcd for C17H14Br2 375.9462,
found 375.9458.
4.2.32. (Z)-1-(1-Bromo-2-chloropenta-1,4-dien-1-yl)-4-(4-
ethylcyclohexyl)benzene (4h). Yield: 56% (114.8 mg) as a yellow oil;
IR (KBr) v 3080, 2921, 1640, 1504, 750 cmꢂ1 1H NMR (400 MHz,
;
Supplementary data
CDCl3)
d 7.25e7.22 (m, 2H), 7.21e7.17 (m, 2H), 5.86e5.76 (m, 1H),
5.15 (dd, J¼10.0, 1.2 Hz, 1H), 5.10 (dd, J¼16.8, 1.6 Hz, 1H), 3.18 (dt,
J¼6.0, 1.2 Hz, 2H), 2.50e2.43 (m, 1H), 1.92e1.86 (m, 4H), 1.48e1.39
(m, 2H), 1.27e1.18 (m, 3H), 1.09e1.02 (m, 2H), 0.908 (t, J¼7.2 Hz,
Supplementary data related to this article can be found at http://
dx.doi.org/10.1016/j.tet.2013.10.100.
3H); 13C NMR (100 MHz, CDCl3)
d 148.8, 136.5, 133.9, 128.5,
References and notes
126.9126.8, 124.2, 117.6, 44.4, 43.0, 39.1, 34.2, 33.1, 29.9, 11.6 ppm;
MS (EI) m/z 111, 141, 155, 168, 253, 410; HRMS(EI) calcd for
1. For selected examples, see: (a) Shin, S.; RajanBabu, T. V. J. Am. Chem. Soc. 2001,
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19H24ClBr 410.0245, found 410.0243.
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4.2.33. (Z)-1-(1,2-Dibromopenta-1,4-dien-1-yl)-4-ethoxybenzene
(4i). Yield: 68% (116.9 mg) as a yellow oil; IR (KBr) v 3079, 2926,
1640, 1476, 753 cmꢂ1 1H NMR (400 MHz, CDCl3)
; d 7.26e7.25 (m,
2H), 6.87e6.84 (m, 2H), 5.86e5.76 (m, 1H), 5.15 (dd, J¼10.4, 1.6 Hz,
1H), 5.10 (dd, J¼16.8, 1.6 Hz, 1H), 4.04 (q, J¼7.2 Hz, 2H), 3.18 (dt,
J¼6.4, 1.2 Hz, 2H), 1.42 (t, J¼7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3)
d
159.3, 133.8, 131.3, 129.9, 126.6, 124.1, 117.5, 114.3, 63.6, 43.0,
14.8 ppm; MS (EI) m/z 115, 128, 158, 186, 237, 267, 344; HRMS(EI)
calcd for C13H14OBr2 343.9411, found 343.9407.
4.2.34. (Z)-1-(1,2-Dibromopenta-1,4-dien-1-yl)-4-fluorobenzene
(4j). Yield: 78% (124.0 mg) as a yellow oil; IR (KBr) v 3079, 2916,
1641, 1595, 730 cmꢂ1
;
1H NMR (400 MHz, CDCl3)
d
7.33e7.30 (m,
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