Palladium-catalyzed coupling of alkynes with unactivated alkenes in ionic liquids: A regio- and stereoselective synthesis of functionalized 1,6-dienes and their analogues

Article abstract of DOI:10.1021/jo402159d

A palladium-catalyzed regio- and stereoselective intermolecular tandem reaction of alkynes and unactivated 1,6-enols in ionic liquids is described, providing a practical, efficient, and versatile method for the synthesis of functionalized 1,6-dienes in moderate to good yields. The present reaction has high functional-group tolerance and gives products on a gram scale. Mechanistic studies indicate that the reaction might proceed via a chain-walking mechanism.

Full text of DOI:10.1021/jo402159d

Article
pubs.acs.org/joc
Palladium-Catalyzed Coupling of Alkynes with Unactivated Alkenes
in Ionic Liquids: A Regio- and Stereoselective Synthesis of
Functionalized 1,6-Dienes and Their Analogues
Jianxiao Li, Shaorong Yang,* Huanfeng Jiang,* Wanqing Wu, and Jinwu Zhao
School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, P. R. China
S
* Supporting Information
ABSTRACT: A palladium-catalyzed regio- and stereoselective
intermolecular tandem reaction of alkynes and unactivated 1,6-
enols in ionic liquids is described, providing a practical,
efficient, and versatile method for the synthesis of function-
alized 1,6-dienes in moderate to good yields. The present
reaction has high functional-group tolerance and gives
products on a gram scale. Mechanistic studies indicate that the reaction might proceed via a chain-walking mechanism.
significant progress that has been achieved, the development of
facile approaches that may allow for the straightforward
preparation of structurally diverse functionalized 1,6-dienes
from easily available starting materials needs to be pursued.
Driven by our interest in nucleopalladation and Pd-catalyzed
cross-coupling reactions in ionic liquids,10 herein we disclose
for the first time an efficient and practical method for the
synthesis of functionalized 1,6-dienes via the Pd-catalyzed
intermolecular cross-coupling reaction of alkyne derivatives
with unactivated alkenes in ionic liquids, which allows the
selective construction of (1E)- or (1Z)-1,6-dienes in a highly
stereoselective fashion. In this reaction, the ionic liquid not only
acts as a solvent in the reaction but also provides the excess
halide ions to control the Z/E selectivity.10f
INTRODUCTION
■
During recent years, transition-metal-catalyzed transformations
for the construction of highly functionalized and complex
molecules in a convenient and concise manner has become a
rapidly expanding area of research, owing in part to readily
accessible starting materials and versatile approaches.1 Toward
this end, there has been a growing interest in the application of
palladium-catalyzed processes, since they usually proceed under
mild reaction conditions and are tolerant of many functional
groups.2 In this regard, nucleopalladation of alkynes has proved
to be a very effective and convenient method for the
construction of both carbon−carbon and carbon−heteroatom
bonds in a rather versatile and atom-economical way.3 Although
significant contributions have been made to this research area,4
most of the methods still have some limitations: (i) in contrast
to other conventional solvents, the use of environmentally
friendly ionic liquids (ILs) is attractive; (ii) high selectivities,
including chemo-, regio-, and stereoselectivity, are still being
sought; (iii) the trapping of alkenylpalladium intermediates
with readily available materials, such as unactivated alkenes, is
also desirable.
The 1,6-diene moiety has been recognized as a privileged
fragment that can be found in many natural products and drug
candidates and exhibits potential biological activities.5 Con-
sequently, many representative methodologies have been
developed for the synthesis of functionalized 1,6-dienes,
including [2 + 2] cycloaddition of allenynes,6 Pd-catalyzed
allylation,7 and Pd-catalyzed decarboxylative protonation.8
Although classical methods for the preparation of 1,6-diene
skeletons are widely recognized in the early research, these
syntheses generally involve multiple steps, harsh reaction
conditions, and/or complicated workup procedures. Very
recently, Ryu and co-workers discovered an elegant method
for the stereoselective synthesis of 2-bromo-1,6-dienes based on
the bromine-radical-mediated rearrangement and addition
reaction of alkylidenecyclopropanes.9 However, complex
substrates are required in these radical reactions. Despite the
RESULTS AND DISCUSSION
■
Our investigation was initiated by using the reaction of
(bromoethynyl)benzene (1a) and pent-4-en-1-ol (2a) as a
model system (Table 1). First, the reactions without aqueous
HCl or PdCl2 failed to afford the desired product 3a, thus
showing the pivotal role of these reagents in the reaction
(entries 1 and 2). To our delight, in the presence of 3 mol %
PdCl2 in 0.50 mL of [Bmim]Cl as the solvent with 0.25 mL of
12 mol/L HCl(aq) as an additive, the starting materials were
consumed within 12 h at room temperature, providing 1,6-
diene 3a in 38% yield with high Z stereoselectivity (Z/E = 98/2
by GC) (entry 3).11 Furthermore, the reaction temperature was
also varied, and 45 °C gave the best yield (entry 5). Neither
higher nor lower reaction temperatures were beneficial for the
conversion (entries 3, 4, and 6). Gratifyingly, a clear
improvement in the yield was observed when 0.35 mL of
HCl(aq) was used (entry 8). Subsequently, various palladium
sources were also tested (entries 10−12), and PdCl2 proved to
Received: September 29, 2013
Published: December 5, 2013
© 2013 American Chemical Society
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a
Table 1. Optimization of the Reaction Conditions
b
entry
ionic liquid
additive (mL)
[Pd]
PdCl2
T (°C)
yield (%)
Z/E
1
2
[Bmim]Cl
[Bmim]Cl
[Bmim]Cl
[Bmim]Cl
[Bmim]Cl
[Bmim]Cl
[Bmim]Cl
[Bmim]Cl
[Bmim]Cl
[Bmim]Cl
[Bmim]Cl
[Bmim]Cl
[Bmim]Cl
[C2OHmim]Cl
[C2O2mim]Cl
−
−
rt
nr
−
−
HCl (0.25)
HCl (0.25)
HCl (0.25)
HCl (0.25)
HCl (0.25)
HCl (0.30)
HCl (0.35)
HCl (0.40)
HCl (0.35)
HCl (0.35)
HCl (0.35)
−
HCl (0.35)
HCl (0.35)
HCl (0.35)
HCl (0.35)
HCl (0.35)
−
PdCl2
rt
nr
3
rt
38
98/2
98/2
98/2
96/4
98/2
98/2
98/2
98/2
−
98/2
84/16
98/2
98/2
73/27
56/44
51/49
4
PdCl2
35
45
50
45
45
45
45
45
45
45
45
45
45
45
45
58
5
PdCl2
76
6
PdCl2
61
7
PdCl2
80
8
PdCl2
98 (88)
92
9
PdCl2
10
11
12
Pd(OAc)2
Pd(PPh3)4
Pd(PPh3)2Cl2
PdCl2
58
nd
47
c
13
81
14
15
PdCl2
70
PdCl2
87
d
16
PdCl2
91
17
−
−
PdCl2
85
e
18
PdCl2
39
a
Unless otherwise noted, the reaction was performed with 1a (0.5 mmol), 2a (0.6 mmol), Pd catalyst (0.025 mol), and ionic liquid (0.5 mL) for 12
b
h. The 1Z/1E ratios were determined by GC. n.r. = no reaction; n.d. = not determined. Determined by GC using dodecane as the internal standard.
The value in parentheses is the isolated yield. 6.0 equiv of LiCl was used. 0.5 mL of HOAc was used. 0.5 mL of DMF was used.
c
d
e
a
Table 2. Pd(II)-Catalyzed Coupling Reaction of Haloalkynes with 2a in [Bmim]Cl
a
Reaction conditions: 1 (0.5 mmol), 2a (0.6 mmol), PdCl2 (3 mol %), [Bmim]Cl (0.5 mL), and HCl (0.35 mL) under an atmosphere of air at 45
°C. Reactions were monitored for completion by TLC.
be optimal, affording 3a in 98% GC yield while the other
palladium sources did not show apparent positive effects
(entries 10−12). Cheap and readily available alkaline metal
salts seemed to be less efficient for the reaction. When LiCl was
employed, the reaction yield was 81% (entry 13). Further
examination of the ionic liquid effects revealed that [Bmim]Cl
was the most suitable solvent for this transformation (entries 8,
14, and 15). Notably, various conventional solvents, such as
HOAc and DMF, were examined under the same reaction
conditions and significantly decreased the yields and stereo-
selectivities (entries 16−18). Thus, the optimized reaction
conditions were affirmed as follows: 3 mol % PdCl2 as the
catalyst and 0.35 mL of HCl(aq) as the additive in [Bmim]Cl at
45 °C for 12 h.
Subsequently, we explored the scope of the reaction between
2a and a variety of haloalkynes under the optimized reaction
conditions (Table 2). All of the bromoalkynes and the
chloroalkynes reacted smoothly and afforded the corresponding
1,6-diene products 3a−r in moderate to high yields (63−94%).
Aromatic alkynyl bromides with either electron-rich or
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electron-poor groups attached to the benzene ring were able to
react with 2a to give the corresponding alkynylation products in
good to excellent yields. Moreover, the reaction tolerated a
variety of substituents, including F, Cl, Br, NO2, OMe, and even
bulky ethylcyclohexyl groups. As for the sterically hindered
bromoalkynes 1h and 1o, the reaction furnished the
corresponding products (Z)-3h and (Z)-3o in yields similar
to that of (Z)-3f or (Z)-3b. Interestingly, alkyl alkynyl bromides
such as 1-bromo-3,3-dimethylbut-1-yne (1n) could also
undergo this transformation in good yields. Furthermore, the
reaction was found to be applicable to various chloroalkynes,
although the reaction of chloroalkynes was relatively sluggish
(Table 2, 3p−r). In terms of the stereoselectivity, all of the
products obtained in the presence of an excess of chloride ions
and acid in a polar solvent resulted from trans addition.12 The
site of halogen addition to asymmetric acetylenes was
controlled by electronic factors.13
Generally, aromatic alkynoates with either an electron-donating
or electron-withdrawing group on the benzene ring were able
to generate the corresponding products in good to excellent
yields with high stereoselectivity (5a−o), which presumably
originated from the selective trans-chloropalladation of alkynes.
Various functional groups, including alkyl, fluoro, chloro,
bromo, cyano, ester, and trifluoromethyl groups, were
compatible with the reaction conditions. The electronic
properties of the substituents on the aromatic alkynoates did
not have a significant influence on the reaction efficiency.
Notably, a vinyl group was tolerated under the standard
reaction conditions, providing 5e in 90% yield with high Z
stereoselectivity. Substitution at the 4-position or 3-position of
the aromatic ring had a slight impact (5b, 5c and 5k, 5l).
Especially, the substrate substituted with two electron-donating
groups gave a good yield (5h). Interestingly, other alkynoates
such as a methyl ester (4p) and a benzyl ester (4q) could be
converted into the corresponding products 5p and 5q in
excellent yields as well. Furthermore, besides the aryl
alkynoates, alkyl alkynoates were also found to be suitable
substrates under the standard conditions (5r and 5s).
Next, the one-pot synthesis of (1Z)-1,2-dihalo-1,6-dienes
from alkynes were examined, and the results are summarized in
Table 3. After the Ag-catalyzed reaction of alkynes was
Table 3. One-Pot Synthesis of (1Z)-1,2-Dihalo-1,6-dienes
from Terminal Alkynes in Ionic Liquids
In addition, we were interested in extending the method to
other alkynes to prepare a variety of highly functionalized 1,6-
diene derivatives (Scheme 1). Remarkably, asymmetrical
internal alkynes participated well in this reaction. For example,
but-1-yn-1-ylbenzene (6a) reacted smoothly with 2a to afford
the 1,6-diene product (Z)-7a in 61% yield (eq 1). In contrast to
other types of alkynes, symmetrical internal alkynes such as 1,2-
diphenylethyne (6b) failed to react with 2a to afford the
desired products under the standard reaction conditions (eq 2).
Moreover, according to the literature reports,15 1,2-diphenyle-
thyne was relatively sluggish in the nucleopalladation of
alkynes. Given our experimental results, we thought that steric
hindrance plays a very important role in this reaction
transformation. Nevertheless, aliphatic 1,4-dichlorobut-2-yne
(6c) was employed successfully in the synthesis of the 1,6-diene
product (Z)-7b in 78% yield with excellent stereoselectivity (eq
3).
Thus far, we have developed a highly efficient and
stereoselective method for the synthesis of chlorinated (1E)-
and (1Z)-1,6-diene derivatives. After the effects of alkynes had
been examined thoroughly, we decided to employ a series of
long-chain 1,n-enols 2 in this transformation. As such, hex-5-en-
1-ol (2b), hept-6-en-1-ol (2c), oct-7-en-1-ol (2d), dec-10-en-1-
ol (2e), and undec-11-en-1-ol (2f) were allowed to react under
the optimal conditions, and good to excellent yields of the
desired products were obtained (Table 5, 8a−e).
To further indicate the universality of this reaction, the scope
of the reaction was expanded to other types of long-chain 1,n-
enols (Scheme 2). Gratifyingly, this method was successfully
applied to pent-4-en-2-ol (2g) and hept-6-en-3-ol (2h), and
these substrates were smoothly converted to the desired
products in 88% and 82% yield, respectively (eqs 4 and 5). The
regioselectivity was elucidated by GC and NMR analysis.
To prove the practicality of the present method in the
synthesis of halogenated 1,6-dienes, a gram-scale synthesis of 3a
was performed, and the result is shown in Scheme 3. When 1.8
g of 1a was utilized, 2.27 g of product 3a (80% yield) was
obtained.
a b
,
entry
alkyne 1
product 3
yield (%)
1
2
3
4
5
6
7
1a, R = H
3a
3b
3c
3e
3k
3m
3o
80
88
83
81
57
71
73
1b, R = 4-Me
1c, R = 3-Me
1e, R = 4-F
1k, R = 4-NO2
1m, R = 4-(4′- ethylcyclohexyl)
1o, R = 2,6-dimethyl
a
Reaction conditions for the first step: alkyne (0.6 mmol), NBS (0.72
mmol), and AgNO3 (5 mol %, 4.2 mg) in [Bmim]Cl (1.00 mL) under
b
an atmosphere of air at room temperature for 4 h. Reaction
conditions for the second step: HCl (12 N, 0.35 mL), 2a (0.5 mmol),
and PdCl2 (3 mol %) in a sealed tube at 45 °C.
completed,14 2a and HCl solution were added to the resultant
mixture. The reaction mixture was then treated at 45 °C. A
similar yield of 3a was observed in the reaction of phenyl-
acetylene (1a) (Table 3, entry 1). The reactions of
arylacetylenes 1a−c, 1m, and 1o bearing an electron-donating
group at the 4- or 3-position of the benzene ring produced the
desired products in good yields (entries 1−3, 6, and 7).
Moreover, relatively high yields were also observed in the
reactions of arylacetylenes 1e and 1k bearing an electron-
withdrawing group on the benzene ring. The desired products
3e and 3k were isolated in 81 and 57% yield, respectively
(entries 4 and 5). This appreciably simplifies the preparation of
1,2-dihalo-1,6-dienes.
To demonstrate the synthetic utility of this protocol, we
further examined the resulting products in transition-metal-
catalyzed cross-coupling reactions. For instance, we studied the
Suzuki−Miyaura coupling16 of halogenated 1,6-diene com-
More interestingly, the chloropalladation of alkynoates under
similar reaction conditions could also initiate this domino-type
reaction with various alkenes to give functionalized 1,6-diene
products. Representative results are summarized in Table 4.
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a
Table 4. Pd(II)-Catalyzed Coupling Reaction of Alkynoates with 2a in [Bmim]Cl
a
Reaction conditions: 4 (0.5 mmol), 2a (0.6 mmol), PdCl2 (3 mol %), [Bmim]Cl (0.5 mL), and HCl (0.35 mL) under an atmosphere of air at 45
°C. Reactions were monitored for completion by TLC.
Scheme 1. Pd(II)-Catalyzed Coupling Reaction of Alkynes
with 2a in [Bmim]Cl
Scheme 2. Pd(II)-Catalyzed Coupling Reaction of Enols
with 1a in [Bmim]Cl
a
Scheme 3. Gram-Scale Synthesis of 3a
Table 5. Pd(II)-Catalyzed Coupling Reaction of 1a with
a
Long-Chain Enols 2 in [Bmim]Cl
a
Reaction conditions: 1a (10 mmol, 1.80 g), 2a (12 mmol, 1.03 g),
PdCl2 (5 mol %, 52.80 mg), [Bmim]Cl (5 mL), and HCl (3.5 mL)
under an atmosphere of air at 45 °C for 18 h.
ethylphenyl)boronic acid (10) under the standard conditions
(0.25 mmol of 3s, 3.0 equiv of 10, 5 mol % PdCl2, 10 mol %
Xphos, 3.0 equiv of K3PO4, and 0.5 mL of toluene at 110 °C for
10 h) afforded a high yield of the target product 11 (Scheme
4). In addition, the resulting 1-chloro-1,6-dienes and 1,2-dihalo-
1,6-dienes could serve as useful intermediates for the rapid
synthesis of stereodefined tetrasubstituted alkenes, which
represent another class of challenging targets in organic
synthesis.
Scheme 4. Pd-Catalyzed Suzuki−Miyaura Reaction of (Z)-5a
a
Reaction conditions: 1a (0.5 mmol), 2 (0.6 mmol), PdCl2 (3 mol %),
[Bmim]Cl (0.5 mL), and HCl (0.35 mL) under an atmosphere of air
at 45 °C. Reactions were monitored for completion by TLC.
pounds with phenylboronic acid derivatives. Treatment of (Z)-
ethyl 2-(chloro(phenyl)methylene)hept-6-enoate (5a) with (4-
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Scheme 5. Control Experiments
Several control experiments were also carried out to get more
insights into this unique transformation (Scheme 5). Under the
standard conditions, the reaction of 1a with 2a in DCl(aq) did
not give the deuterated 1,6-diene product, but (Z)-3a was
obtained in 87% yield (eq 6). Furthermore, when 1a and 2a
were allowed to react in DCl(aq) without ionic liquid, similarly
no deuterated 1,6-diene product could be detected while (Z)-
3a was obtained with lower stereoselectivity (eq 7). The
deuterated experiment results were identified by NMR analysis.
All of these observations indicated that external proton is not
involved in this chemical process. That is, direct protonolysis of
the carbon−palladium bond does not occur in this case. Also,
when 3,3-dimethylpent-4-en-1-ol (2i) was employed to react
with 1a under the standard conditions, no reaction occurred at
all (eq 8), which indicates that the β-hydrogen of the carbon−
palladium bond is important for this transformation. Finally, a
control experiment employing alkenes with different leaving
groups was carried out, and the desired product (Z)-3a was
obtained under similar conditions (eq 9). These results suggest
that alkenes with a better leaving group could also smoothly be
converted to the corresponding products in the absence of
HCl(aq).
Scheme 6. Proposed Mechanism
On the basis of the above results and the literature,3,17
a
(1Z)-1,6-dienes and their analogues with high regio- and
diastereoselectivities in moderate to excellent yields. The
employment of ionic liquids under mild conditions makes
this transformation green and practical. The key step in the
present reaction is likely to involve a chain-walking process.
Most importantly, this methodology provides a new tool for the
construction of diversely substituted 1,6-diene derivatives from
inexpensive starting materials.
tentative mechanism involving chain walking is proposed in
Scheme 6. The Pd complex is initially formed in situ in the
IL,10a,f and vinylpalladium intermediate A is formed by trans-
chloropalladation of the alkyne in a polar solvent system12 in
the presence of excess chloride ions.18 Then, intermediate A
can undergo alkene insertion to generate Pd−alkyl intermediate
B. Subsequently, B undergoes rapid β-hydride elimination and
reinsertion to change the position of the metal on the alkyl
chain, producing intermediate C. Finally, β-heteroatom
elimination affords the target product. Noticeably, although
the chain-walking mechanism has been widely incorporated
into many olefin polymerization processes,19 its use for
carbon−carbon bond formation in small organic molecules,
especially for unactivated long-chain enols, has rarely been
investigated.20
EXPERIMENTAL SECTION
■
General Methods. Melting points were measured using a melting
point instrument and are uncorrected. H and 13C NMR spectra were
1
recorded on a 400 MHz NMR spectrometer. The chemical shifts are
referenced to signals at 7.24 and 77.0 ppm, respectively, and
chloroform was used as a solvent with TMS as the internal standard.
IR spectra were obtained with an infrared spectrometer on either
potassium bromide pellets or liquid films between two potassium
bromide pellets. GC−MS data were obtained using electron
ionization. HRMS was carried out on a high-resolution mass
spectrometer (LCMS-IT-TOF). TLC was performed using commer-
cially available 100−400 mesh silica gel plates (GF254). Unless
otherwise noted, purchased chemicals were used without further
CONCLUSION
■
In summary, we have developed a practical, efficient, and
versatile method for the synthesis of functionalized (1E)- and
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purification. The ionic liquids ([Bmim]Cl,21 [C2OHmim]Cl,22 and
[C2O2mim]Cl23) were synthesized using reported procedures. The
bromoalkynes,14 chloroalkynes,24 and alkynoates25 were prepared
according to the literature.
General Procedure. Alkyne (0.5 mmol), 2 (0.6 mmol), PdCl2 (3
mol %), ionic liquid (0.5 mL), and HCl (0.35 mL) were mixed in a
test tube (10 mL) equipped with a magnetic stirring bar. The mixture
was stirred under an atmosphere of air at 45 °C. After the reaction was
completed, 10 mL of ethyl acetate was added into the tube. The
combined organic layers were washed with brine to neutral, dried over
MgSO4, and concentrated in vacuum. Purification of the residue by
preparative TLC afforded the desired products.
(Z)-1-(2-Bromo-1-chlorohepta-1,6-dien-1-yl)-3-chlorobenzene
1
(3g). Yield: 90% (143.1 mg) as a yellow oil; H NMR (400 MHz,
CDCl3) δ 7.35−7.29 (m, 3H), 7.21−7.19 (m, 1H), 5.73−5.63 (m,
1H), 4.96−4.90 (m, 2H), 2.46−2.42 (m, 2H), 1.97 (q, J = 7.2 Hz,
2H), 1.73−1.66 (m, 2H); 13C NMR (100 MHz, CDCl3) δ 139.1,
137.5, 134.4, 129.8, 129.5, 129.1, 128.8, 128.4, 126.9, 115.3, 37.5, 32.4,
28.1; IR (KBr) νmax/cm−1 3079, 2930, 1600, 1520, 1456, 918, 760; MS
(EI) m/z 75, 101, 125, 127, 149, 162, 168, 185, 203, 205, 241, 243,
285, 318; HRMS (EI) calcd for C13H13Cl2Br 317.9578, found
317.9573.
(Z)-1-(2-Bromo-1-chlorohepta-1,6-dien-1-yl)-2-chlorobenzene
1
(3h). Yield: 92% (146.2 mg) as a yellow oil; H NMR (400 MHz,
CDCl3) δ 7.44−7.42 (m, 1H), 7.34−7.27 (m, 3H), 5.70−5.60 (m,
1H), 4.93−4.86 (m, 2H), 2.37−2.22 (m, 2H), 1.95−1.90 (m, 2H),
1.74−1.56 (m, 2H); 13C NMR (100 MHz, CDCl3) δ 137.7, 136.2,
133.2, 130.6, 130.4, 130.1, 129.2, 127.7, 127.1, 115.0, 37.4, 32.5, 27.5;
IR (KBr) νmax/cm−1 3080, 2929, 1640, 1500, 1480, 920, 740; MS (EI)
m/z 114, 127, 149, 162, 164, 197, 203, 205, 241, 318; HRMS (EI)
calcd for C13H13Cl2Br 317.9578, found 317.9573.
(Z)-(2-Bromo-1-chlorohepta-1,6-dien-1-yl)benzene (3a). Yield:
88% (124.9 mg) as a yellow oil; H NMR (400 MHz, CDCl3) δ
1
7.41−7.34 (m, 5H), 5.76−5.66 (m, 1H), 4.98−4.92 (m, 2H), 2.50−
2.46 (m, 2H), 1.99 (dd, J = 14.2, 7.0 Hz, 2H), 1.76−1.69 (m, 2H); 13C
NMR (100 MHz, CDCl3) δ 137.7, 137.5, 131.1, 128.9, 128.7, 128.6,
127.4, 115.1, 37.5, 32.5, 28.2; IR (KBr) νmax/cm−1 3077, 2965, 1642,
1607, 1451, 1285, 920, 794; MS (EI) m/z 115, 128, 141, 163, 169,
195, 205, 207, 249, 284; HRMS (EI) calcd for C13H14ClBr 283.9967,
found 283.9960.
(Z)-1-Bromo-4-(2-bromo-1-chlorohepta-1,6-dien-1-yl)benzene
1
(3i). Yield: 93% (168.3 mg) as a yellow oil; H NMR (400 MHz,
CDCl3) δ 7.52−7.50 (m, 2H), 7.20−7.18 (m, 2H), 5.73−5.63 (m,
1H), 4.96−4.90 (m, 2H), 2.43 (t, J = 7.6 Hz, 2H), 1.96 (dd, J = 14.0,
7.2 Hz, 2H), 1.72−1.64 (m, 2H); 13C NMR (100 MHz, CDCl3) δ
137.5, 136.4, 131.8, 130.3, 129.9, 128.0, 123.1, 115.3, 37.5, 32.4, 28.2;
IR (KBr) νmax/cm−1 3080, 2921, 1643, 1480, 735; MS (EI) m/z 88,
115, 128, 149, 162, 193, 204, 206, 285, 287, 362; HRMS (EI) calcd for
C13H13ClBr2 361.9073, found 361.9065.
(Z)-1-(2-Bromo-1-chlorohepta-1,6-dien-1-yl)-4-methylbenzene
1
(3b). Yield: 92% (137.1 mg) as a yellow oil; H NMR (400 MHz,
CDCl3) δ 7.22−7.16 (m, 4H), 5.74−5.64 (m, 1H), 4.95−4.89 (m,
2H), 2.45 (t, J = 7.6 Hz, 2H), 2.37 (s, 3H), 1.96 (dd, J = 14.0, 7.0 Hz,
2H), 1.72−1.65 (m, 2H); 13C NMR (100 MHz, CDCl3) δ 138.9,
137.8, 134.6, 131.2, 129.2, 128.5, 127.0, 115.0, 37.6, 32.5, 28.6, 21.3; IR
(KBr) νmax/cm−1 3079, 2921, 1641, 1603, 1418, 920, 760; MS (EI) m/
z 115, 129, 142, 155, 163, 183, 219, 221, 263, 298; HRMS (EI) calcd
for C14H16ClBr 298.0124, found 298.0119.
(Z)-1-(2-Bromo-1-chlorohepta-1,6-dien-1-yl)-4-ethoxybenzene
1
(3j). Yield: 74% (121.4 mg) as a yellow oil; H NMR (400 MHz,
CDCl3) δ 7.24−7.22 (m, 2H), 6.88−6.84 (m, 2H), 5.74−5.64 (m,
1H), 4.96−4.89 (m, 2H), 4.05 (q, J = 7.2 Hz, 2H), 2.45 (t, J = 7.6 Hz,
2H), 1.96 (dd, J = 14.4, 7.2 Hz, 2H), 1.68 (dt, J = 14.8, 7.6 Hz, 2H),
1.43 (t, J = 7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3) δ 159.3, 137.8,
131.2, 130.0, 128.1, 126.8, 115.1, 114.4, 63.6, 37.6, 28.2, 14.8; IR
(KBr) νmax/cm−1 3079, 2921, 1640, 1500, 1475, 916, 752; MS (EI) m/
z 77, 102, 115, 131, 166, 185, 194, 213, 249, 277, 328; HRMS (EI)
calcd for C15H18OClBr 328.0230, found 328.0225.
(Z)-1-(2-Bromo-1-chlorohepta-1,6-dien-1-yl)-4-nitrobenzene
(3k). Yield: 63% (103.6 mg) as a yellow solid; mp 116.3−117.9 °C; 1H
NMR (400 MHz, CDCl3) δ 8.26−8.18 (m, 2H), 7.60−7.51 (m, 2H),
5.72−5.62 (m, 1H), 4.93−4.90 (m, 2H), 2.45 (t, J = 8.0 Hz, 2H), 1.97
(q, J = 7.2 Hz, 2H), 1.75−1.68 (m, 2H); 13C NMR (100 MHz,
CDCl3) δ 143.7, 137.3, 132.8, 129.8, 128.5, 123.9, 123.6, 115.5, 37.5,
32.4, 28.1; IR (KBr) νmax/cm−1 3078, 2980, 1636, 1522, 1490, 1435,
924, 711; MS (EI) m/z 102, 115, 128, 149, 162, 169, 214, 232, 249,
251, 289, 314, 329; HRMS (EI) calcd for C13H13BrClNO2 328.9818,
found 328.9814.
(Z)-1-(2-Bromo-1-chlorohepta-1,6-dien-1-yl)-3-methylbenzene
1
(3c). Yield: 90% (134.1 mg) as a yellow oil; H NMR (400 MHz,
CDCl3) δ 7.25−7.23 (m, 1H), 7.16−7.09 (m, 3H), 5.73−5.63 (m,
1H), 4.94−4.88 (m, 2H), 2.44 (t, J = 7.6 Hz, 2H), 2.36 (s, 3H), 1.96
(dd, J = 14.0, 7.0 Hz, 2H), 1.69 (dt, J = 14.8, 7.2 Hz, 2H); 13C NMR
(100 MHz, CDCl3) δ 138.3, 137.7, 137.4, 131.2, 129.6, 129.2, 128.4,
127.1, 125.7, 115.1, 37.5, 32.5, 28.2, 21.4; IR (KBr) νmax/cm−1 3077,
2960, 1600, 1538, 1456, 918, 760; MS (EI) m/z 115, 129, 142, 155,
163, 183, 219, 221, 265, 298; HRMS (EI) calcd for C14H16ClBr
298.0124, found 298.0117.
(Z)-1-(2-Bromo-1-chlorohepta-1,6-dien-1-yl)-4-ethylbenzene
1
(3d). Yield: 91% (141.9 mg) as a yellow oil; H NMR (400 MHz,
CDCl3) δ 7.24−7.18 (m, 4H), 5.74−5.64 (m, 1H), 4.95−4.88 (m,
2H), 2.66 (q, J = 7.6 Hz, 2H), 2.46 (m, 2H), 1.96 (dd, J = 14.0, 7.0 Hz,
2H), 1.72−1.65 (m, 2H), 1.27−1.25 (m, 3H); 13C NMR (100 MHz,
CDCl3) δ 145.2, 137.8, 134.8, 131.3, 128.6, 128.0, 127.0, 115.0, 37.6,
32.5, 28.6, 28.2, 15.3; IR (KBr) νmax/cm−1 3077, 2960, 1635, 1600,
1520, 1456, 761; MS (EI) m/z 115, 128, 143, 155, 176, 197, 233, 235,
257, 279, 312; HRMS (EI) calcd for C15H18ClBr 312.0280, found
312.0274.
(Z)-4-(2-Bromo-1-chlorohepta-1,6-dien-1-yl)-4′-propyl-1,1′-bi-
phenyl (3l). Yield: 78% (156.8 mg) as a yellow solid; mp 160.5−161.7
1
°C; H NMR (400 MHz, CDCl3) δ 7.59−7.57 (m, 2H), 7.51 (d, J =
(Z)-1-(2-Bromo-1-chlorohepta-1,6-dien-1-yl)-4-fluorobenzene
1
8.4 Hz, 2H), 7.37 (d, J = 8.4 Hz, 2H), 7.27−7.21 (m, 2H), 5.74−5.64
(m, 1H), 4.96−4.88 (m, 2H), 2.63 (t, J = 8.0 Hz, 2H), 2.52−2.48 (m,
2H), 1.98 (dd, J = 14.4, 7.2 Hz, 2H), 1.75−1.63 (m, 4H), 0.97 (t, J =
7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3) δ 142.5, 141.7, 137.7,
137.5, 136.0, 131.0, 129.1, 129.0, 127.4, 127.0, 126.9, 115.1, 37.7, 37.6,
32.5, 28.3, 24.5, 13.9; IR (KBr) νmax/cm−1 3078, 2926, 1640, 1504,
1416, 920, 752; MS (EI) m/z 101, 115, 133, 152, 165, 189, 202, 217,
245, 259, 287, 288, 323, 325, 369, 389, 402; HRMS (EI) calcd for
C22H24ClBr 402.0750, found 402.0746.
(3e). Yield: 84% (126.8 mg) as a yellow oil; H NMR (400 MHz,
CDCl3) δ 7.32−7.28 (m, 2H), 7.09−7.04 (m, 2H), 5.73−5.63 (m,
1H), 4.95−4.89 (m, 2H), 2.44−2.41 (m, 2H), 1.96 (dd, J = 14.0, 7.0
Hz, 2H), 1.72−1.64 (m, 2H); 13C NMR (100 MHz, CDCl3) δ 162.7
(J = 248.1 Hz), 137.6, 133.5 (J = 3.5 Hz), 130.6 (J = 8.4 Hz), 130.0,
127.7, 115.7 (J = 21.7 Hz), 115.2, 37.5, 32.5, 28.1; IR (KBr) νmax/cm−1
3079, 2916, 1641, 1503, 1232, 922, 731; MS (EI) m/z 107, 109, 133,
146, 159, 181, 187, 213, 223, 225, 267, 302; HRMS (EI) calcd for
C13H13FClBr 301.9873, found 301.9868.
(Z)-1-(2-Bromo-1-chlorohepta-1,6-dien-1-yl)-4-(4-
ethylcyclohexyl)benzene (3m). Yield: 85% (167.4 mg) as a yellow oil;
1H NMR (400 MHz, CDCl3) δ 7.24−7.18 (m, 4H), 5.73−5.63 (m,
1H), 4.93−4.87 (m, 2H), 1.98−1.88 (m, 6H), 1.72−1.65 (m, 2H),
1.49−1.39 (m, 2H), 1.31−1.18 (m, 4H), 1.07−1.00 (m, 2H), 0.91 (t, J
= 7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3) δ 148.8, 137.8, 134.8,
131.3, 128.6, 127.0, 115.0, 44.4, 39.1, 37.5, 34.2, 33.1, 32.5, 30.0, 28.2,
11.5; IR (KBr) νmax/cm−1 3080, 2921, 2851, 1640, 1450, 920, 750; MS
(EI) m/z 69, 91, 111, 115, 141, 153, 169, 203, 205, 235, 250, 285, 287,
(Z)-1-(2-Bromo-1-chlorohepta-1,6-dien-1-yl)-4-chlorobenzene
1
(3f). Yield: 94% (149.4 mg) as a yellow oil; H NMR (400 MHz,
CDCl3) δ 7.36−7.34 (m, 2H), 7.26−7.24 (m, 2H), 5.73−5.63 (m,
1H), 4.96−4.90 (m, 2H), 2.44−2.41 (m, 2H), 1.96 (dd, J = 14.0, 7.0
Hz, 2H), 1.72−1.64 (m, 2H); 13C NMR (100 MHz, CDCl3) δ 137.5,
135.9, 134.9, 130.0, 129.8, 128.9, 128.0, 115.3, 37.5, 32.5, 28.2; IR
(KBr) νmax/cm−1 3081, 2920, 1642, 1487, 922, 748; MS (EI) m/z 113,
139, 152, 165, 191, 207, 229, 253, 281, 305, 307, 318; HRMS (EI)
calcd for C13H13Cl2Br 317.9578, found 317.9570.
12482
dx.doi.org/10.1021/jo402159d | J. Org. Chem. 2013, 78, 12477−12486

The Journal of Organic Chemistry
Article
315, 359, 394; HRMS (EI) calcd for C21H28ClBr 394.1063, found
394.1059.
m/z 91, 105, 115, 129, 139, 141, 163, 183, 199, 211, 257, 277, 292;
HRMS (ESI) calcd for C17H21ClNaO2 315.1122, found 315.1127.
+
(Z)-Ethyl 2-(Chloro(m-tolyl)methylene)hept-6-enoate (5c). Yield:
82% (119.8 mg) as a yellow oil; 1H NMR (400 MHz, CDCl3) δ 7.29−
7.26 (m, 1H), 7.18−7.14 (m, 3H), 5.72−5.62 (m, 1H), 4.94−4.88 (m,
2H), 4.34 (q, J = 7.2 Hz, 2H), 2.37 (s, 3H), 2.31−2.27 (m, 2H), 1.97
(q, J = 7.2 Hz, 2H), 1.54−1.47 (m, 2H), 1.37 (t, J = 7.2 Hz, 3H); 13C
NMR (100 MHz, CDCl3) δ 168.1, 138.2, 137.8, 137.2, 133.3, 131.6,
129.1, 128.3, 125.5, 115.0, 61.2, 33.0, 31.3, 27.5, 21.4, 14.2; IR (KBr)
νmax/cm−1 3076, 2961, 1723, 1643, 1495, 1440, 756; MS (EI) m/z
105, 115, 129, 139, 163, 191, 211, 247, 277, 292; HRMS (ESI) calcd
(Z)-6-Bromo-7-chloro-8,8-dimethylnona-1,6-diene (3n). Yield:
1
84% (110.1 mg) as a yellow oil; H NMR (400 MHz, CDCl3) δ
5.85−5.75 (m, 1H), 5.07−5.00 (m, 2H), 2.77−2.73 (m, 2H), 2.10 (q, J
= 7.2 Hz, 2H), 1.76 (dt, J = 15.2, 7.6 Hz, 2H), 1.34 (s, 9H); 13C NMR
(100 MHz, CDCl3) δ 142.1, 137.8, 126.7, 115.3, 40.5, 38.8, 33.1, 31.4,
28.7; IR (KBr) νmax/cm−1 3081, 2923, 1500, 745; MS (EI) m/z 67, 79,
93, 107, 108, 121, 149, 169, 187, 209, 229, 251, 264; HRMS (EI) calcd
for C11H18ClBr 264.0280, found 264.0276.
(Z)-2-(2-Bromo-1-chlorohepta-1,6-dien-1-yl)-1,3-dimethylben-
zene (3o). Yield: 84% (131.0 mg) as a yellow oil; 1H NMR (400 MHz,
CDCl3) δ 7.05−6.98 (m, 3H), 5.72−5.62 (m, 1H), 4.94−4.87 (m,
2H), 2.32 (s, 3H), 2.30−2.27 (m, 2H), 2.26 (s, 3H), 1.91 (dd, J = 14.4,
7.2 Hz, 2H), 1.65−1.57 (m, 2H); 13C NMR (100 MHz, CDCl3) δ
139.1, 137.8, 136.1, 133.9, 131.3, 130.1, 128.9, 127.2, 126.8, 114.9,
37.3, 32.5, 27.8, 21.2, 19.2; IR (KBr) νmax/cm−1 3079, 2923, 1640,
1446, 920, 756; MS (EI) m/z 115, 128, 141, 162, 169, 177, 197, 198,
233, 235, 245, 285, 312; HRMS (EI) calcd for C15H18ClBr 312.0280,
found 312.0272.
(Z)-1-(1,2-Dichlorohepta-1,6-dien-1-yl)-4-ethylbenzene (3p).
Yield: 75% (100.0 mg) as a yellow oil; 1H NMR (400 MHz,
CDCl3) δ 7.26−7.19 (m, 5H), 5.75−5.65 (m, 1H), 4.95−4.89 (m,
2H), 2.67 (q, J = 7.6 Hz, 2H), 2.40 (t, J = 7.6 Hz, 2H), 1.97 (dd, J =
14.4, 7.2 Hz, 2H), 1.25 (t, J = 7.6 Hz, 3H); 13C NMR (100 MHz,
CDCl3) δ 145.2, 137.8, 134.6, 133.6, 128.8, 128.5, 128.0, 115.0, 35.5,
32.6, 28.6, 27.2, 15.3; IR (KBr) νmax/cm−1 3079, 2960, 1600, 1458,
760; MS (EI) m/z 115, 128, 141, 149, 169, 177, 197, 199, 203, 205,
233, 239, 241, 243, 268; HRMS (EI) calcd for C15H18Cl2 268.0786,
found 268.0783.
(Z)-1-Bromo-4-(1,2-dichlorohepta-1,6-dien-1-yl)benzene (3q).
Yield: 73% (116.0 mg) as a yellow oil; 1H NMR (400 MHz,
CDCl3) δ 7.52−7.50 (m, 2H), 7.21−7.18 (m, 2H), 5.74−5.64 (m,
1H), 4.96−4.91 (m, 2H), 2.36 (t, J = 7.6 Hz, 2H), 1.97 (dd, J = 14.4,
7.2 Hz, 2H), 1.72−1.65 (m, 2H); 13C NMR (100 MHz, CDCl3) δ
137.5, 136.1, 134.7, 131.8, 130.5, 128.1, 123.2, 115.3, 35.5, 32.6, 27.2;
IR (KBr) νmax/cm−1 3079, 2980, 1636, 1490, 1430, 738; MS (EI) m/z
114, 127, 149, 162, 184, 197, 218, 241, 265, 285, 318; HRMS (EI)
calcd for C13H13BrCl2 317.9578, found 317.9572.
+
for C17H21ClNaO2 315.1122, found 315.1123.
(Z)-Ethyl 2-(Chloro(4-ethylphenyl)methylene)hept-6-enoate (5d).
Yield: 90% (137.8 mg) as a yellow oil; 1H NMR (400 MHz, CDCl3) δ
7.27 (d, J = 8.0 Hz, 2H), 7.21 (d, J = 8.0 Hz, 2H), 5.73−5.63 (m, 1H),
4.94−4.88 (m, 2H), 4.34 (q, J = 7.2 Hz, 2H), 2.67 (q, J = 7.6 Hz, 2H),
2.37−2.26 (m, 2H), 1.98 (dd, J = 14.4, 7.2 Hz, 2H), 1.51 (dt, J = 15.2,
7.6 Hz, 2H), 1.37 (t, J = 7.2 Hz, 3H), 1.26 (t, J = 7.6 Hz, 3H); 13C
NMR (100 MHz, CDCl3) δ 168.2, 145.3, 137.8, 134.6, 133.1, 131.6,
128.5, 127.9, 115.0, 61.2, 33.0, 31.3, 28.7, 27.5, 15.3, 14.2; IR (KBr)
νmax/cm−1 3078, 2958, 1726, 1638, 1515, 1280, 755; MS (EI) m/z
115, 128, 153, 177, 205, 225, 279, 306; HRMS (ESI) calcd for
+
C18H23ClNaO2 329.1279, found 329.1284.
(Z)-Ethyl 2-(Chloro(4-vinylphenyl)methylene)hept-6-enoate (5e).
Yield: 90% (136.8 mg) as a yellow oil; 1H NMR (400 MHz, CDCl3) δ
7.42 (d, J = 8.2 Hz, 2H), 7.32 (d, J = 8.2 Hz, 2H), 6.72 (dd, J = 17.6,
10.8 Hz, 1H), 5.80 (d, J = 17.6 Hz, 1H), 5.73−5.63 (m, 1H), 4.95−
4.89 (m, 2H), 4.34 (q, J = 7.2 Hz, 1H), 2.33−2.29 (m, 2H), 1.98 (dd, J
= 14.4, 7.2 Hz, 2H), 1.51 (dt, J = 15.2, 7.6 Hz, 2H), 1.37 (t, J = 7.2 Hz,
3H); 13C NMR (100 MHz, CDCl3) δ 168.0, 138.3, 137.7, 136.5,
136.0, 133.5, 131.2, 128.8, 126.2, 115.2, 115.1, 61.3, 33.0, 31.4, 27.5,
14.2; IR (KBr) νmax/cm−1 3077, 2981, 1725, 1643, 1455, 1268, 754;
MS (EI) m/z 115, 131, 153, 175, 195, 203, 230, 232, 269, 304; HRMS
+
(ESI) calcd for C18H22ClO2 305.1303, found 305.1307.
(Z)-Ethyl 2-((4-(tert-Butyl)phenyl)chloromethylene)hept-6-enoate
1
(5f). Yield: 86% (143.6 mg) as a yellow oil; H NMR (400 MHz,
CDCl3) δ 7.39 (d, J = 8.0 Hz, 2H), 7.29 (d, J = 8.0 Hz, 2H), 5.72−5.62
(m, 1H), 4.93−4.87 (m, 2H), 4.34 (q, J = 7.2 Hz, 2H), 2.35−2.28 (m,
2H), 1.98 (q, J = 7.2 Hz, 2H), 1.50 (dd, J = 15.2, 7.6 Hz, 2H), 1.37 (t,
J = 7.2 Hz, 3H), 1.33 (s, 9H); 13C NMR (100 MHz, CDCl3) δ 168.2,
152.2, 137.8, 134.2, 133.1, 131.6, 128.2, 125.3, 114.9, 61.2, 34.7, 33.0,
31.3, 31.2, 27.5, 14.2; IR (KBr) νmax/cm−1 3075, 2961, 1726, 1514,
1480, 1440, 1259, 755; MS (EI) m/z 115, 141, 169, 181, 197, 209,
225, 245, 277, 299, 319, 321, 334; HRMS (ESI) calcd for
(Z)-4-(1,2-Dichlorohepta-1,6-dien-1-yl)-4′-propyl-1,1′-biphenyl
(3r). Yield: 67% (120.0 mg) as a yellow solid; mp 158.1−159.4 °C; 1H
NMR (400 MHz, CDCl3) δ 7.60−7.58 (m, 2H), 7.53−7.50 (m, 2H),
7.38 (d, J = 8.4 Hz, 2H), 7.26 (m, d, J = 9.2 Hz, 2H), 5.75−5.65 (m,
1H), 4.96−4.89 (m, 2H), 2.64 (t, J = 7.6 Hz, 2H), 2.44 (t, J = 7.6 Hz,
2H), 1.99 (dd, J = 14.4, 7.2 Hz, 2H), 1.76−1.64 (m, 4H), 0.98 (t, J =
7.6 Hz, 3H); 13C NMR (100 MHz, CDCl3) δ 142.5, 141.7, 137.7,
137.5, 135.8, 134.0, 129.3, 129.0, 128.2, 127.0, 126.9, 115.1, 37.7, 35.6,
32.6, 31.3, 24.5, 13.9; IR (KBr) νmax/cm−1 3080, 2927, 1640, 1501,
921, 756; MS (EI) m/z 101, 115, 133, 152, 165, 178, 189, 202, 204,
227, 245, 287, 323, 325, 358; HRMS (EI) calcd for C22H24Cl2
358.1225, found 358.1248.
+
C20H27ClNaO2 357.1592, found 357.1592.
(Z)-Ethyl 2-([1,1′-Biphenyl]-4-ylchloromethylene)hept-6-enoate
1
(5g). Yield: 83% (146.9 mg) as a yellow oil; H NMR (400 MHz,
CDCl3) δ 7.65−7.57 (m, 4H), 7.47−7.37 (m, 5H), 5.74−5.64 (m,
1H), 4.96−4.89 (m, 2H), 4.34 (q, J = 7.2 Hz, 2H), 2.38−2.33 (m,
2H), 2.00 (dd, J = 14.2, 7.2 Hz, 2H), 1.59−1.50 (m, 2H), 1.39 (t, J =
7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3) δ 168.0, 141.9, 140.2,
137.7, 136.1, 133.6, 131.2, 129.0, 128.9, 127.8, 127.1, 127.0, 115.1,
61.3, 33.0, 31.4, 27.6, 14.2; IR (KBr) νmax/cm−1 3072, 2928, 1725,
1642, 1484, 1453, 758; MS (EI) m/z 115, 139, 165, 178, 191, 203,
207, 225, 245, 253, 280, 291, 319, 354; HRMS (ESI) calcd for
(Z)-Ethyl 2-(Chloro(phenyl)methylene)hept-6-enoate (5a). Yield:
91% (126.5 mg) as a yellow oil; 1H NMR (400 MHz, CDCl3) δ 7.40−
7.34 (m, 5H), 5.71−5.61 (m, 1H), 4.93−4.88 (m, 2H), 4.34 (q, J = 7.2
Hz, 2H), 2.29 (t, J = 8.0 Hz, 2H), 1.97 (dd, J = 14.4, 7.2 Hz, 2H),
1.54−1.47 (m, 2H), 1.38 (t, J = 7.2 Hz, 3H); 13C NMR (100 MHz,
CDCl3) δ 168.0, 137.7, 137.3, 133.5, 131.4, 129.0, 128.5, 128.4, 115.0,
61.3, 33.0, 31.3, 27.5, 14.2; IR (KBr) νmax/cm−1 3078, 2981, 1725,
1638, 1480, 1440, 1287, 758; MS (EI) m/z 63, 77, 91, 105, 115, 128,
141, 163, 169, 177, 197, 204, 233, 243, 249, 278; HRMS (ESI) calcd
+
C22H23ClNaO2 377.1279, found 377.1279.
(Z)-Ethyl 2-(Chloro(3,5-dimethylphenyl)methylene)hept-6-
1
enoate (5h). Yield: 81% (123.9 mg) as a yellow oil; H NMR (400
MHz, CDCl3) δ 6.99 (s, 1H), 6.97 (s, 2H), 5.73−5.63 (m, 1H), 4.95−
4.86 (m, 2H), 4.33 (q, J = 7.2 Hz, 2H), 2.33 (s, 6H), 2.29 (t, J = 8.0
Hz, 2H), 1.98 (q, J = 7.2 Hz, 2H), 1.50 (dd, J = 15.2, 7.6 Hz, 2H), 1.37
(t, J = 7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3) δ 168.1, 138.0,
137.8, 137.1, 133.1, 130.7, 126.2, 114.9, 61.2, 33.0, 29.7, 27.5, 21.2,
14.2; IR (KBr) νmax/cm−1 3075, 2925, 1644, 1563, 1480, 1455, 754;
MS (EI) m/z 115, 128, 143, 155, 177, 197, 207, 225, 271, 306; HRMS
+
for C16H19ClNaO2 301.0966, found 301.0972.
(Z)-Ethyl 2-(Chloro(p-tolyl)methylene)hept-6-enoate (5b). Yield:
88% (128.6 mg) as a yellow oil; 1H NMR (400 MHz, CDCl3) δ 7.26−
7.24 (m, 2H), 7.19−7.17 (m, 2H), 5.73−5.63 (m, 1H), 4.95−4.89 (m,
2H), 4.36−4.28 (m, 2H), 2.38 (s, 3H), 2.32−2.28 (m, 2H), 1.97 (dd, J
= 14.4, 7.2 Hz, 2H), 1.50 (dt, J = 15.2, 7.6 Hz, 2H), 1.37 (t, J = 7.2 Hz,
3H); 13C NMR (100 MHz, CDCl3) δ 168.1, 139.1, 137.8, 134.4,
133.0, 129.4, 129.1, 128.4, 115.0, 61.2, 33.1, 31.4, 27.6, 21.3, 14.2; IR
(KBr) νmax/cm−1 3075, 2925, 1724, 1645, 1538, 1455, 754; MS (EI)
+
(ESI) calcd for C18H23ClNaO2 329.1279, found 329.1280.
(Z)-Ethyl 2-(Chloro(4-fluorophenyl)methylene)hept-6-enoate (5i).
Yield: 80% (118.4 mg) as a yellow oil; 1H NMR (400 MHz, CDCl3) δ
7.36−7.33 (m, 2H), 7.10−7.06 (m, 2H), 5.72−5.62 (m, 1H), 4.95−
4.89 (m, 2H), 4.34 (q, J = 7.2 Hz, 2H), 2.29−2.26 (m, 2H), 1.97 (q, J
12483
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The Journal of Organic Chemistry
Article
= 7.2 Hz, 2H), 1.54−1.46 (m, 2H), 1.37 (t, J = 7.2 Hz, 3H); 13C NMR
(100 MHz, CDCl3) δ 167.8, 162.8 (J = 248.0 Hz), 137.6, 133.3 (J =
3.5 Hz), 130.5 (J = 8.3 Hz), 130.3, 115.5 (J = 21.8 Hz), 115.1, 61.3,
33.0, 31.3, 27.4, 14.2; IR (KBr) νmax/cm−1 3076, 2928, 1726, 1643,
1506, 1446, 1267, 755; MS (EI) m/z 107, 109, 123, 133, 147, 159,
177, 187, 209, 222, 251, 261, 296; HRMS (ESI) calcd for
(Z)-Methyl 2-(Chloro(phenyl)methylene)hept-6-enoate (5p).
Yield: 91% (120.1 mg) as a yellow oil; 1H NMR (400 MHz,
CDCl3) δ 7.39−7.33 (m, 5H), 5.71−5.61 (m, 1H), 4.94−4.88 (m,
2H), 3.87 (s, 3H), 2.31−2.27 (m, 2H), 1.96 (q, J = 7.2 Hz, 2H), 1.53−
1.46 (m, 2H); 13C NMR (100 MHz, CDCl3) δ 168.5, 137.7, 137.2,
133.2, 131.9, 129.1, 128.5, 115.1, 52.2, 33.0, 31.3, 27.6; IR (KBr) νmax
/
cm−1 3075, 2926, 1729, 1644, 1516, 756; MS (EI) m/z 105, 115, 128,
+
C16H18FClNaO2 319.0872, found 319.0875.
+
169, 177, 197, 221, 229, 264; HRMS (ESI) calcd for C15H17ClNaO2
(Z)-Ethyl 2-(Chloro(4-chlorophenyl)methylene)hept-6-enoate
1
(5j). Yield: 83% (129.5 mg) as a yellow oil; H NMR (400 MHz,
287.0809, found 287.0806.
CDCl3) δ 7.37 (d, J = 8.0 Hz, 2H), 7.29 (d, J = 8.0 Hz, 2H), 5.72−5.62
(m, 1H), 4.95−4.90 (m, 2H), 4.34 (q, J = 7.2 Hz, 2H), 2.29−2.26 (m,
2H), 1.97 (q, J = 7.2 Hz, 2H), 1.54−1.46 (m, 2H), 1.37 (t, J = 7.2 Hz,
3H); 13C NMR (100 MHz, CDCl3) δ 167.8, 137.6, 135.6, 135.1,
134.1, 130.1, 129.9, 128.7, 115.2, 61.4, 32.9, 31.3, 27.4, 14.2; IR (KBr)
νmax/cm−1 3087, 2959, 1726, 1645, 1516, 1268, 754; MS (EI) m/z
125, 139, 151, 168, 183, 203, 205, 231, 277, 283, 312; HRMS (ESI)
(Z)-Benzyl 2-(Chloro(phenyl)methylene)hept-6-enoate (5q).
Yield: 88% (149.6 mg) as a yellow oil; 1H NMR (400 MHz,
CDCl3) δ 7.44 (d, J = 7.2 Hz, 2H), 7.40−7.35 (m, 8H), 5.65−5.55 (m,
1H), 5.31 (s, 2H), 4.89−4.85 (m, 2H), 2.31−2.27 (m, 2H), 1.92 (q, J
= 7.2 Hz, 2H), 1.49−1.42 (m, 2H); 13C NMR (100 MHz, CDCl3) δ
167.8, 137.6, 137.3, 135.5, 133.1, 132.1, 129.1, 128.6, 128.5, 128.4,
128.4, 115.0, 67.1, 33.0 31.3, 27.5; IR (KBr) νmax/cm−1 3069, 2924,
1725, 1643, 1549, 1518, 755; MS (EI) m/z 115, 128, 167, 169, 205,
207, 260, 306, 340; HRMS (ESI) calcd for C21H21ClNaO2+ 363.1122,
found 363.1123.
+
calcd for C16H18Cl2NaO2 335.0576, found 335.0577.
(Z)-Ethyl 2-((4-Bromophenyl)chloromethylene)hept-6-enoate
1
(5k). Yield: 85% (151.3 mg) as a yellow oil; H NMR (400 MHz,
CDCl3) δ 7.53 (d, J = 8.4 Hz, 2H), 7.23 (d, J = 8.4 Hz, 2H), 5.72−5.62
(m, 1H), 4.95−4.90 (m, 2H), 4.34 (q, J = 7.2 Hz, 2H), 2.29−2.25 (m,
2H), 1.97 (dd, J = 14.2, 7.2 Hz, 2H), 1.50 (dt, J = 15.2, 7.6 Hz, 2H),
1.37 (t, J = 7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3) δ 167.7, 137.5,
136.1, 134.1, 131.7, 130.2, 130.1, 123.3, 115.2, 61.4, 33.0, 31.3, 27.4,
14.2; IR (KBr) νmax/cm−1 3075, 2927, 1726, 1642, 1482, 1452, 1267,
753; MS (EI) m/z 115, 149, 153, 168, 195, 207, 227, 247, 275, 293,
(Z)-Ethyl 2-(1-Chloroethylidene)hept-6-enoate (5r). Yield: 84%
(90.7 mg) as a yellow oil; H NMR (400 MHz, CDCl3) δ 5.83−5.73
1
(m, 1H), 5.04−4.97 (m, 2H), 4.26 (q, J = 7.2 Hz, 2H), 2.33 (dd, J =
15.2, 7.6 Hz, 2H), 2.16 (s, 3H), 2.08 (dd, J = 14.4, 7.2 Hz, 2H), 1.58−
1.50 (m, 2H), 1.32 (t, J = 7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3)
δ 168.1, 137.9, 131.2, 131.0, 115.2, 61.0, 33.0, 30.3, 27.3, 22.7, 14.1; IR
(KBr) νmax/cm−1 3083, 2930, 1644, 1515, 1436, 755; MS (EI) m/z 55,
67, 79, 91, 97, 107, 129, 153, 171, 181, 207, 216; HRMS (ESI) calcd
+
323, 356; HRMS (ESI) calcd for C16H18BrClNaO2 379.0071, found
379.0074.
+
for C11H17ClNaO2 239.0809, found 239.0809.
(Z)-Methyl 3-Chloro-2-(pent-4-en-1-yl)oct-2-enoate (5s). Yield:
89% (114.8 mg) as a yellow oil; 1H NMR (400 MHz, CDCl3) δ 5.82−
5.72 (m, 1H), 5.04−4.97 (m, 2H), 3.78 (s, 3H), 2.41−2.37 (m, 2H),
2.34−2.31 (m, 2H), 2.07 (dd, J = 14.4, 7.2 Hz, 2H), 1.62−1.50 (m,
4H), 1.35−1.29 (m, 4H), 0.91 (t, J = 7.2 Hz, 3H); 13C NMR (100
MHz, CDCl3) δ 168.7, 137.8, 136.0, 130.9, 115.2, 51.9, 35.2, 33.0,
30.1, 27.6, 27.1, 22.4, 13.8; IR (KBr) νmax/cm−1 3077, 2930, 1645,
1547, 1454, 753; MS (EI) m/z 55, 79, 91, 107, 121, 125, 149, 163, 173,
(Z)-Ethyl 2-((3-Bromophenyl)chloromethylene)hept-6-enoate
1
(5l). Yield: 79% (140.6 mg) as a yellow oil; H NMR (400 MHz,
CDCl3) δ 7.50 (d, J = 8.4 Hz, 2H), 7.27 (d, J = 6.8 Hz, 2H), 5.72−5.62
(m, 1H), 4.95−4.90 (m, 2H), 4.34 (q, J = 7.2 Hz, 2H), 2.30−2.26 (m,
2H), 1.98 (q, J = 7.2 Hz, 2H), 1.51 (dt, J = 15.2, 7.6 Hz, 2H), 1.37 (t, J
= 7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3) δ 167.6, 139.1, 137.5,
134.4, 132.1, 131.5, 130.0, 129.5, 127.2, 122.4, 115.2, 61.4, 32.9, 31.2,
27.4, 14.2; IR (KBr) νmax/cm−1 3074, 2981, 1727, 1644, 1560, 1465,
754; MS (EI) m/z 115, 129, 141, 170, 185, 213, 241, 283, 315, 356;
+
191, 223, 258; HRMS (ESI) calcd for C14H23ClNaO2 281.1279,
found 281.1283.
+
HRMS (ESI) calcd for C16H18BrClNaO2 379.0071, found 379.0060.
(E)-(1-Chloro-2-ethylhepta-1,6-dien-1-yl)benzene (7a). Yield: 61%
(Z)-Ethyl 2-(Chloro(4-cyanophenyl)methylene)hept-6-enoate
1
1
(71.4 mg) as a yellow oil; H NMR (400 MHz, CDCl3) δ 7.36−7.32
(5m). Yield: 75% (113.6 mg) as a yellow oil; H NMR (400 MHz,
(m, 3H), 7.18−7.16 (m, 2H), 5.78−5.68 (m, 1H), 4.98−4.92 (m, 2H),
2.54 (q, J = 7.2 Hz, 2H), 2.42 (q, J = 8.0 Hz, 2H), 2.02 (dd, J = 14.4,
7.2 Hz, 2H), 1.39 (dt, J = 15.2, 7.6 Hz, 2H), 1.21 (t, J = 7.6 Hz, 3H);
13C NMR (100 MHz, CDCl3) δ 141.6, 138.2, 136.5, 132.6, 128.5,
128.0, 126.8, 114.8, 34.2, 33.3, 28.9, 27.4, 13.0; IR (KBr) νmax/cm−1
3079, 2968, 1538, 1457, 754; MS (EI) m/z 65, 77, 91, 103, 115, 128,
157, 169, 192, 207, 234; HRMS (EI) calcd for C15H19Cl 234.1175,
found 234.1173.
CDCl3) δ 7.70 (d, J = 8.4 Hz, 2H), 7.48 (d, J = 8.4 Hz, 2H), 5.70−5.60
(m, 1H), 4.94−4.90 (m, 2H), 4.35 (q, J = 7.2 Hz, 2H), 2.28−2.24 (m,
2H), 1.97 (q, J = 7.2 Hz, 2H), 1.50 (dt, J = 15.2, 7.6 Hz, 2H), 1.38 (t, J
= 7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3) δ 167.3, 141.6, 137.3,
135.2, 132.3, 129.4, 128.9, 118.1, 115.4, 112.9, 61.6, 32.9, 31.2, 27.3,
14.2; IR (KBr) νmax/cm−1 3076, 2925, 1725, 1644, 1500, 1456, 755;
MS (EI) m/z 113, 127, 140, 154, 166, 194, 216, 249, 268, 294, 303;
+
HRMS (ESI) calcd for C17H18ClNNaO2 326.0918, found 326.0920.
(Z)-7,8-Dichloro-6-(chloromethyl)octa-1,6-diene (7b). Yield: 78%
(88.1 mg) as a yellow oil; H NMR (400 MHz, CDCl3) δ 5.85−5.75
(Z)-Ethyl 2-(Chloro(4-(trifluoromethyl)phenyl)methylene)hept-6-
1
1
enoate (5n). Yield: 81% (140.1 mg) as a yellow oil; H NMR (400
MHz, CDCl3) δ 7.67 (d, J = 8.0 Hz, 2H), 7.48 (d, J = 8.4 Hz, 2H),
5.71−5.61 (m, 1H), 4.94−4.89 (m, 2H), 4.36 (q, J = 7.2 Hz, 2H),
2.29−2.25 (m, 2H), 1.97 (q, J = 7.2 Hz, 2H), 1.55−1.47 (m, 2H), 1.38
(t, J = 7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3) δ 167.5, 140.7,
137.5, 134.7, 133.1, 131.2, 129.5, 129.0, 125.6, 125.5, 115.2, 61.5, 32.9,
31.2, 27.4, 14.2; IR (KBr) νmax/cm−1 3076, 2929, 2362, 1727, 1644,
1515, 1455, 755; MS (EI) m/z 115, 133, 153, 183, 197, 209, 237, 259,
(m, 1H), 5.08−5.01 (m, 2H), 4.30 (s, 2H), 4.26 (s, 2H), 2.36 (t, J =
8.0 Hz, 2H), 2.11 (q, J = 7.2 Hz, 2H), 1.62 (dt, J = 10.4, 7.6 Hz, 2H);
13C NMR (100 MHz, CDCl3) δ 137.8, 137.5, 129.8, 115.6, 44.9, 43.8,
33.3, 30.5, 27.4; IR (KBr) νmax/cm−1 3086, 2926, 1523, 1271, 720; MS
(EI) m/z 77, 91, 105, 113, 126, 153, 177, 226; HRMS (EI) calcd for
C9H13Cl3 226.0083, found 226.0075.
(Z)-(2-Bromo-1-chloroocta-1,7-dien-1-yl)benzene (8a). Yield:
+
1
283, 311, 346; HRMS (ESI) calcd for C17H18ClF3NaO2 369.0840,
91% (135.6 mg) as a yellow oil; H NMR (400 MHz, CDCl3) δ
found 369.0838.
7.40−7.30 (m, 5H), 5.78−5.68 (m, 1H), 4.95−4.91 (m, 2H), 2.44 (t, J
= 7.6 Hz, 2H), 1.95 (dd, J = 14.2, 7.0 Hz, 2H), 1.64−1.56 (m, 2H),
1.29 (dt, J = 14.4, 7.2 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ 138.4,
137.6, 130.9, 128.9, 128.7, 128.6, 127.6, 114.7, 37.8, 33.2, 28.3, 27.6; IR
(KBr) νmax/cm−1 3078, 2983, 1600, 1455, 1420, 720; MS (EI) m/z
102, 129, 131, 174, 183, 211, 254, 298; HRMS (EI) calcd for
C14H16ClBr 298.0124, found 298.0118.
(Z)-Methyl 4-(1-Chloro-2-(ethoxycarbonyl)hepta-1,6-dien-1-yl)-
benzoate (5o). Yield: 77% (129.4 mg) as a yellow oil; 1H NMR
(400 MHz, CDCl3) δ 8.07 (d, J = 8.4 Hz, 2H), 7.44 (d, J = 8.4 Hz,
2H), 5.70−5.60 (m, 1H), 4.94−4.88 (m, 2H), 4.35 (q, J = 7.2 Hz,
2H), 3.94 (s, 3H), 2.30−2.26 (m, 2H), 1.96 (q, J = 7.2 Hz, 2H), 1.54−
1.47 (m, 2H), 1.38 (t, J = 7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3)
δ 167.6, 166.4, 141.5, 137.5, 134.4, 130.6, 130.1, 129.7, 128.6, 115.2,
61.4, 52.3, 32.9, 31.3, 27.4, 14.2; IR (KBr) νmax/cm−1 3079, 2926,
1725, 1642, 1437, 756; MS (EI) m/z 115, 128, 149, 153, 195, 207,
(Z)-(2-Bromo-1-chloronona-1,8-dien-1-yl)benzene (8b). Yield:
1
90% (140.4 mg) as a yellow oil; H NMR (400 MHz, CDCl3) δ
7.38−7.35 (m, 3H), 7.32−7.30 (m, 2H), 5.80−5.70 (m, 1H), 4.98−
4.91 (m, 2H), 2.42 (t, J = 8.0 Hz, 2H), 1.99 (dd, J = 14.2, 7.0 Hz, 2H),
1.59 (dt, J = 14.8, 7.6 Hz, 2H), 1.32−1.25 (m, 2H), 1.24−1.16 (m,
+
227, 249, 273, 301, 336; HRMS (ESI) calcd for C18H21ClNaO4
359.1021, found 359.1025.
12484
dx.doi.org/10.1021/jo402159d | J. Org. Chem. 2013, 78, 12477−12486

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Article
2H); 13C NMR (100 MHz, CDCl3) δ 138.8, 137.6, 130.8, 128.7,
128.5, 127.7, 114.4, 37.9, 33.6, 28.7, 28.4, 27.9; IR (KBr) νmax/cm−1
3076, 2981, 1632, 1445, 1424, 736; MS (EI) m/z 115, 137, 144, 146,
165, 172, 174, 200, 211, 246, 281, 312; HRMS (EI) calcd for
C15H18ClBr 312.0280, found 312.0276.
ASSOCIATED CONTENT
* Supporting Information
Spectral data for all new compounds and NOE studies of the
stereochemistry of 3a. This material is available free of charge
via the Internet at http://pubs.acs.org.
■
S
(Z)-(2-Bromo-1-chlorodeca-1,9-dien-1-yl)benzene (8c). Yield:
1
81% (132.0 mg) as a yellow oil; H NMR (400 MHz, CDCl3) δ
AUTHOR INFORMATION
Corresponding Authors
*Fax: (+) (+86) 20-8711-2906. E-mail: lisryang@scut.edu.cn.
*E-mail: jianghf@scut.edu.cn.
Notes
7.37−7.34 (m, 3H), 7.32−7.30 (m, 2H), 5.82−5.72 (m, 1H), 4.99−
4.91 (m, 2H), 2.42 (t, J = 7.6 Hz, 2H), 1.98 (dd, J = 14.2, 7.0 Hz, 2H),
1.59−1.56 (m, 2H), 1.33−1.30 (m, 2H), 1.21−1.16 (m, 2H); 13C
NMR (100 MHz, CDCl3) δ 139.0, 137.6, 130.7, 128.8, 128.7, 128.5,
127.8, 114.3, 37.9, 33.7, 28.8, 28.7, 28.6, 28.3; IR (KBr) νmax/cm−1
3074, 2980, 1628, 1430, 726; MS (EI) m/z 95, 115, 129, 151, 163,
183, 195, 211, 218, 241, 243, 245, 326; HRMS (EI) calcd for
C16H20ClBr 326.0437, found 326.0430.
■
The authors declare no competing financial interest.
(Z)-(2-Bromo-1-chlorododeca-1,11-dien-1-yl)benzene (8d). Yield:
78% (138.1 mg) as a yellow oil; 1H NMR (400 MHz, CDCl3) δ 7.38−
7.34 (m, 3H), 7.33−7.30 (m, 2H), 5.85−5.75 (m, 1H), 5.00−4.91 (m,
2H), 2.42 (t, J = 7.6 Hz, 2H), 2.02 (dd, J = 14.2, 7.0 Hz, 2H), 1.59−
1.55 (m, 2H), 1.36−1.31 (m, 2H), 1.26−1.18 (m, 8H); 13C NMR
(100 MHz, CDCl3) δ 139.2, 137.6, 130.7, 128.8, 128.7, 128.5, 127.8,
114.1, 37.9, 33.8, 29.3, 29.1, 29.0, 28.9, 28.9, 28.4; IR (KBr) νmax/cm−1
3078, 2980, 1633, 1490, 1445, 728; MS (EI) m/z 115, 129, 157, 183,
200, 202, 237, 275, 317, 354; HRMS (EI) calcd for C18H24ClBr
354.0750, found 354.0746.
(Z)-(2-Bromo-1-chlorotrideca-1,12-dien-1-yl)benzene (8e). Yield:
77% (141.7 mg) as a yellow oil; 1H NMR (400 MHz, CDCl3) δ 7.39−
7.35 (m, 3H), 7.32−7.30 (m, 2H), 5.86−5.76 (m, 1H), 5.01−4.91 (m,
2H), 2.42 (t, J = 7.6 Hz, 2H), 2.03 (dd, J = 14.2, 7.0 Hz, 2H), 1.59−
1.55 (m, 2H), 1.37−1.32 (m, 2H), 1.26−1.18 (m, 10H); 13C NMR
(100 MHz, CDCl3) δ 139.2, 137.6, 130.7, 128.8, 128.7, 128.5, 127.8,
ACKNOWLEDGMENTS
■
The authors are grateful to the National Natural Science
Foundation of China (21102047 and 20932002), the National
Basic Research Program of China (973 Program)
(2011CB808600), and the Fundamental Research Funds for
the Central Universities (2014ZP0004 and 2014ZZ0046) for
financial support.
REFERENCES
■
(1) For reviews, see: (a) Negishi, E.; Coperet, C.; Ma, S.; Liou, S. Y.;
Liu, F. Chem. Rev. 1996, 96, 365−393. (b) Zeni, G.; Larock, R. C.
Chem. Rev. 2004, 104, 2285−2309. (c) Zeni, G.; Larock, R. C. Chem.
Rev. 2006, 106, 4644−4680. (d) Patil, N. P.; Yamamoto, Y. Chem. Rev.
2008, 108, 3395−3442. (e) Li, B.-J.; Shi, Z.-J. Chem. Soc. Rev. 2012, 41,
5588−5598. (f) Chow, W. K.; Yuen, O. Y.; Choy, P. Y.; So, C. M.;
Lau, C. P.; Wong, W. T.; Kwong, F. Y. RSC Adv. 2013, 3, 12518−
12539. (g) Gulevich, A. V.; Dudnik, A. S.; Chernyak, N.; Gevorgyan,
V. Chem. Rev. 2013, 113, 3084−3213.
114.1, 38.0, 33.8, 29.4, 29.3, 29.2, 29.1, 29.0, 28.9, 28.4; IR (KBr) νmax
/
cm−1 3079, 2985, 1637, 1504, 1445, 724; MS (EI) m/z 95, 115, 129,
151, 157, 171, 191, 218, 253, 289, 368; HRMS (EI) calcd for
C19H26ClBr 368.0906, found 368.0903.
(2) For reviews, see: (a) Brennfuhrer, A.; Neumann, H.; Beller, M.
̈
(2-Bromo-1-chlorohepta-1,5-dien-1-yl)benzene (9a). Yield: 88%
(124.9 mg) as a yellow oil; 1H NMR (400 MHz, CDCl3) δ 7.37−7.30
(m, 5H), 5.50−5.38 (m, 1H), 5.29−5.20 (m, 1H), 2.49−2.42 (m, 2H),
2.35−2.30 (m, 1H), 2.28−2.23 (m, 1H), 1.61 (d, J = 6.4 Hz, 1.5H),
1.55 (d, J = 6.8 Hz, 1.5H); 13C NMR (100 MHz, CDCl3) δ 137.6
(137.5), 131.3 (131.2), 128.9 (128.8), 128.8 (127.8), 128.7 (128.7),
128.5 (128.5), 127.0 (126.9), 126.5 (125.7), 38.2 (37.9), 31.8 (26.4),
17.9 (12.8); IR (KBr) νmax/cm−1 3049, 2983, 1600, 1501, 1464, 720;
MS (EI) m/z 115, 150, 169, 205, 231, 252, 284; HRMS (EI) calcd for
C13H14ClBr 283.9967, found 283.9964.
(2-Bromo-1-chloronona-1,6-dien-1-yl)benzene (9b). Yield: 82%
(127.9 mg) as a yellow oil; 1H NMR (400 MHz, CDCl3) δ 7.37−7.30
(m, 5H), 5.39−5.29 (m, 1H), 5.27−5.16 (m, 1H), 2.45−2.41 (m, 2H),
1.99−1.86 (m, 4H), 1.68−1.60 (m, 2H), 0.917 (d, J = 7.6 Hz, 1.5H),
0.883 (d, J = 7.6 Hz, 1.5H); 13C NMR (100 MHz, CDCl3) δ 137.6
(137.5), 132.9 (132.5), 130.9 (130.8), 128.8 (128.8), 128.7 (128.6),
128.5 (128.5), 127.9 (127.8), 127.6 (127.4), 37.8 (37.5), 31.2 (20.5),
29.1 (28.9), 26.0 (25.5), 14.2 (13.8); IR (KBr) νmax/cm−1 3044, 2987,
1605, 1500, 1445, 728; MS (EI) m/z 115, 128, 141, 155, 197, 237,
249, 298, 312; HRMS (EI) calcd for C15H18ClBr 312.0280, found
312.0274.
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