Unique Regio- and Stereoselectivity in Pd-Catalyzed Chlorocarbonylation Reaction of 2-Phenylethynyl Selenides and 2-Alkylethynyl Selenides. Highly Stereoselective Synthesis of 2-Seleno-3-chloroacrylates

Article abstract of DOI:10.1021/jo0006977

Regio- and stereoselectivity in the chloropalladation carbonylation reaction of different acetylenic selenides in the presence of 0.05 equiv of PdCl₂ and 3 equiv of cupric chloride under 1 atm of carbon monoxide affording 2-seleno-3-chloroacrylates were investigated. Opposite stereoselectivities were observed with 2-phenylethynyl selenides and 2-alkylethynyl selenides: the reactions of 2-phenylethynyl selenides afforded (E)-2-seleno-3-chloro-3-phenylacrylates, while the reactions of 2-alkylethynyl selenides gave (Z)-2-seleno-3-chloro-3-alkylacrylates. A chloropalladation carbonylation mechanism for this reaction was proposed. The regio- and stereoselective chloropalladation of the carbon-carbon triple bond in acetylenic selenides affords 1-enylpalladium intermediates, in which the palladium atom connects with the carbon atom bonding with the selenium atom. Carbonylation in the presence of an alcohol affords 2-seleno-3-chloroacrylates.

Full text of DOI:10.1021/jo0006977

J . Org. Chem. 2000, 65, 6561-6565
6561
Un iqu e Regio- a n d Ster eoselectivity in P d -Ca ta lyzed
Ch lor oca r bon yla tion Rea ction of 2-P h en yleth yn yl Selen id es a n d
2
-Alk yleth yn yl Selen id es. High ly Ster eoselective Syn th esis of
2
-Selen o-3-ch lor oa cr yla tes
Xian Huang* and Aiming Sun
Department of Chemistry, Zhejiang University, Xixi Campus,
Hangzhou 310028, Peoples Republic of China
huangx@mail.hz.zj.cn
Received May 8, 2000
Regio- and stereoselectivity in the chloropalladation carbonylation reaction of different acetylenic
selenides in the presence of 0.05 equiv of PdCl and 3 equiv of cupric chloride under 1 atm of carbon
2
monoxide affording 2-seleno-3-chloroacrylates were investigated. Opposite stereoselectivities were
observed with 2-phenylethynyl selenides and 2-alkylethynyl selenides: the reactions of 2-phenyl-
ethynyl selenides afforded (E)-2-seleno-3-chloro-3-phenylacrylates, while the reactions of 2-alkyl-
ethynyl selenides gave (Z)-2-seleno-3-chloro-3-alkylacrylates. A chloropalladation carbonylation
mechanism for this reaction was proposed. The regio- and stereoselective chloropalladation of the
carbon-carbon triple bond in acetylenic selenides affords 1-enylpalladium intermediates, in which
the palladium atom connects with the carbon atom bonding with the selenium atom. Carbonylation
in the presence of an alcohol affords 2-seleno-3-chloroacrylates.
In tr od u ction
there are no reports of the stereoselective synthesis of
functionalized, fully substituted 3-chloroacrylates. In this
paper, we report our recent study on the palladium(II)-
catalyzed highly regio- and stereoselective carbonylation
reaction of acetylenic selenides (eq 1).
Stereoselectivity is one of the most pursued goals of
synthetic organic chemists. The highly stereoselective
synthesis of tetrasubstituted alkenes, especially tetra-
substituted 2-enoates, is of high interest because of the
capability for further evolution of the functional groups.
1
These compounds are prepared by the Arbusov-Wittig
and the Peterson reactions2 as a mixture of E and Z
isomers. Both methods afford the corresponding products
in low yields when enolizable or bulky ketones are used
as the substrates. These materials can also be prepared
by the reaction of nucleophiles with substituted allylic
3
4
chlorides and other methods. Among our efforts devoted
5
Resu lts a n d Discu ssion
to the chemistry of alkynes is an interest in the stereo-
selective synthesis of 3-chloroacrylates, valuable inter-
Ca r bon yla tion of 2-P h en yleth yn yl Selen id es. The
treatment of 2-phenylethynyl ethyl selenide with metha-
6
mediates in organic synthesis and known to exhibit some
12
7
biological properties. These compounds can usually be
nol and 3 equiv of CuCl
of 5 mol % of PdCl afforded a mixture of the expected
methyl-2-ethylseleno-3-chloro-3-phenylacrylate (3b) and
2
in CO (1 atm) under the catalysis
8
,9
prepared by esterification of the corresponding acids
and the reaction of lithium chloride in acetic acid with
-alkynoates.10 Recent reports of the synthesis of substi-
2
2
1
1
tuted 3-chloroacrylates have been published. However,
(6) (a) Smith, A. B.; Kilenyi, S. N. Tetrahedron Lett. 1985, 26, 4419.
(
b) Bey, P.; Vevert, J . P. J . Org. Chem. 1980, 45, 3249. (c) Teutsch, J .
*
To whom correspondence should be addressed. Fax: 86571
807077.
1) Wadsworth, W. J . In Organic Reactions; J ohn Wiley & Sons:
New York, 1977; Vol. 25, pp 660-708.
2) (a) Peterson, D. J . J . Org. Chem. 1968, 33, 780. (b) Peterson, D.
G.; Bonnet, A.; Aszodi, J .; Costerousse, G. Eur. Pat. Appl. Ep. 1984,
153, 229. (Chem. Abstr., 1986, 105, 6351y). (d) Ege, G.; Franz, H. J .
Heterocycl. Chem. 1982, 19, 1267. (e) Larock, R. C.; Narayanan, K.;
Hershberger, S. S. J . Org. Chem. 1983, 48, 4377. (f) Zhang, C.; Lu. X.
Synthesis 1996, 586. (h) Miyaura, N.; Sasaki, N.; Itoh, M.; Suzuki, A.
Tetrahedron Lett. 1977, 3369.
(7) (a) Herrett, R. A.; Kurtz, A. N. Science 1963, 141, 1192. (b) Kurtz,
A. N.; Herrett, R. A. Union Carbide Corp., Belg. 1963, 631, 83; Chem.
Abstr. 1964, 60, 15071b.
8
(
(
J .; Hudrlik, P. F. J . Am. Chem. Soc. 1975, 97, 1464. (c) Ager, D. J . In
Organic Reactions; J ohn Wiley & Sons: New York, 1990; Vol. 38, pp
1
-223.
3) (a) Mathew, J . J . Org. Chem. 1992, 57, 2753. (b) Mathew, J .;
Alink, B. J . Org. Chem. 1990, 55, 3880.
4) (a) Hagiwara, H.; Nakayama, K.; Uda, H. Bull. Chem. Soc. J pn.
975, 48, 3769. (b) Iwai, H.; Kosugi, H.; Uda, H.; Kawai, M. Bull. Chem.
(
(8) Kultz, A. N.; Billups, W. E.; Greenlee, R. B.; Hamil, H. F.; Pace,
W. T. J . Org. Chem. 1965, 30, 3141.
(
1
(9) Bowden, K. Can. J . Chem. 1966, 44, 661.
Soc. J pn. 1977, 50, 242. (c) Nokami, J .; Nishiuchi, K.; Wakabayashi,
S.; Okawara, R. Tetrahedron Lett. 1980, 4455. (d) Leyendecker, L.;
Comte, M. T. Ibid. 1982, 23, 5031. (e) Durman, J .; Hunt, P. G.; Warren,
S. Tetrahedron Lett. 1983, 24, 2113.
(10) (a) Ma, S.; Lu, X. Tetrahedron Lett. 1990, 31, 7653. (b) Ma, S.;
Lu. X. J . Chem. Soc., Chem. Commun. 1990, 1643. (c) Ma, S.; Lu, X.;
Li. Z. J . Org. Chem. 1992, 57, 709. (d) Lu. X. Zhu, G.; Ma, S. Chin. J .
Chem. 1993, 11, 267.
(11) Li, J .; J iang, H.; Feng, A.; J ia, L. J . Org. Chem. 1999, 64, 5984.
(12) Comasseto, J . V.; Ferreira, J . T. B.; Petragnani, N. J . Orga-
nomet. Chem. 1981, 216, 287.
(5) (a) Zhu, L. S.; Huang, Z. Z.; Huang, X. Tetrahedron 1996, 52,
9
7
819. (b) Huang, X.; Zhu, L. S., J . Chem. Soc., Perkin Trans. 1 1996,
67. (c) Yang, D. Y.; Huang, X. Synlett 1997, 891.
1
0.1021/jo0006977 CCC: $19.00 © 2000 American Chemical Society
Published on Web 09/01/2000

6
562 J . Org. Chem., Vol. 65, No. 20, 2000
Huang and Sun
Ta ble 1. P a lla d iu m -Ca ta lyzed Ca r bon yla tion of
Ta ble 2. Syn th esis of
2
-P h en yleth yn yl Eth yl Selen id e (1b) w ith Meth a n ol (2a )
(E)-2-Selen o-3-ch lor o-3-p h en yla cr yla tes by Ca r bon yla tion
a
a
in Differ en t Solven ts
of 2-P h en yleth yn yl Selen id es in Ben zen e
%
yieldb
reaction
time (h)
yield of
3 (%) (E/Z)
reaction
time (h)
1
2
b
entry
R (1)
Me (1a ) Me (2a )
Et (1b) Me (2a )
i-Pr (1c) Me (2a )
R (2)
entry
solvent
3b (E/Z)
4a (E/Z)
1
2
3
4
5
6
7
8
1.5
2
2
8
4
2.5
24
24
95 (3a , >98/2)
93 (3b, >98/2)
90 (3c, >97/3)
75 (3d , >97/3)
82 (3e, >97/3)
88 (3f, >99/1)
60 (3g, >95/5)
75 (3h , 82/18)
1
2
3
4
5
6
7
8
HOAc
MeOH
CH2Cl2/MeOH (4:1)
CH3CN/MeOH (4:1)
CH3CN
36
24
16
24
24
24
4
45 (>98/2)
58 (>98/2)
85 (>98/2)
72 (>98/2) 31 (>98/2)
60 (>98/2) 35 (>98/2)
74 (74/16)
88 (>98/2)
93 (>98/2)
9 (>98/2)
7 (>98/2)
9 (>98/2)
Et (1b)
Et (1b)
Et (1b)
Et (1b)
Ph (1d )
Et (2b)
i-Pr (2c)
n-Bu (2d )
p-NO2PhCH2 (2e)
Me (2a )
THF
0
0
0
CH2Cl2
C6H6
2
a
a
A mixture of 1 (1 mmol), PdCl2 (9 mg, 0.05 mmol), CuCl2 (405
mg, 3 mmol), and alcohol (0.8 mL) in 10 mL of benzene was stirred
under atmospheric pressure of carbon monoxide at room temper-
ature. b Isolated yield based on 1 used, and the ratio of E/Z was
A mixture of 1b (209 mg, 1 mmol), PdCl2 (9 mg, 0.05 mmol),
CuCl2 (405 mg, 3 mmol), methanol (0.8 mL), and the solvent (10
mL) was stirred under 1atm of carbon monoxide at room temper-
b
ature. Isolated yield based on 1b.
1
determined by 300 MHz H NMR spectra.
the dichlorination product (4a ) with moderate to good
selectivities of 3b over 4a (eq 2, Table 1, entries 1-5).
This carbonylation reaction is solvent dependent, similar
to previous reports by Lu et al.13 In all cases in Table 1,
the stereoselectivity for 3b is high. The corresponding
reaction in THF afforded 3b as the sole product albeit in
lower stereoselectivity (Table 1, entry 6). Surprisingly,
Sch em e 1
2 2
the reaction in CH Cl or benzene afforded 3b in high
yield as well as E-selectivity (Table 1, entries 7 and 8).
The regio- and the stereoselectivity of this reaction was
4
determined by the treatment of ((E)-3b) with LiAlH at
room temperature in THF for 3 h to afford E-cinnamyl
alcohol ((E)-5) in 76% isolated yield (eq 3).14
hols gave good yields of products ((E)-3) with fairly good
regio- and stereoselectivity although the corresponding
carbonylation reaction of 2-phenylethynyl phenyl selenide
afforded product 3h with a lower stereoselectivity (Table
2
, entry 8).
Ca r bon yla tion of 2-Alk yleth yn yl Selen id es. Fol-
lowing the study of 2-phenylethynyl selenides, attention
was turned to the difference between 2-phenyethynyl
selenides and 2-alkylethynyl selenides. The chlorocarbon-
ylation of 2-pentylethynyl ethyl selenide (6c) under
similar reaction conditions afforded the (Z)-isomer in 82%
yield with excellent regio- and stereoselectivity, indicat-
ing a completely opposite stereochemistry (eq 5).
When Z-methyl cinnamate ((Z)-5′) was treated with
LiAlH under the same reaction conditions, no E-cin-
4
namyl alcohol ((E)-5) was obtained, and 86% of Z-
cinnamyl alcohol ((Z)-5) was isolated, indicating that
E-cinnamyl alcohol ((E)-5) was not produced from Z-
cinnamyl alcohol ((Z)-5) by isomerization (eq 4).
All the results indicate that the chloropalladation of
-phenylethynyl ethyl selenide proceeded with strong
preference for the addition of the palladium at the carbon
bonding with the selenium group, and the chloropalla-
dation of 2-phenylethynyl ethyl selenide is a syn-addition
process. The procedure can be readily applied to other
-phenylethynyl selenides with different aliphatic alco-
hols (Table 2).
The palladium-catalyzed carbonylation reaction of
-phenylethynyl selenides with different aliphatic alco-
The regio- and stereoselectivity were confirmed by
2
4
treatment of (Z)-7c with LiAlH to give a 70% yield of
1
5
the known compound (Z)-2-octen-1-ol (Z-8c). The ste-
reospecificity of this reaction was further confirmed by
treatment of (Z)-7c with DIBAL to give (Z)-2-ethylseleno-
3
-chloro-2-octen-1-ol (Z-9c), the configuration of which
was determined by NOE (Scheme 1).
The procedure can also be applied to other 2-alkyl-
ethynyl selenides with different aliphatic alcohol as
shown in Table 3.
2
2
4 9
The results in Table 3 indicate that when R ) n-C H ,
(
13) J i, J .; Lu, X. Tetrahedron 1994, 50, 9067.
1
(14) Goetz, E. B.; Dubois, J . E. J . Org. Chem. 1975, 40, 221.
n-C
5
H
11, n-C
6
H
3 2 5
13 and R ) CH or C H , the acetylenic

Stereoselective Synthesis of 2-Seleno-3-chloroacrylates
J . Org. Chem., Vol. 65, No. 20, 2000 6563
Ta ble 3. P a lla d iu m -Ca ta lyzed Ca r bon yla tion of 2-Alk yleth yn yl Selen id esa
6
time
(h)
yield of
7(%) (Z/E)
1
2
b
entry
R (6)
R (6)
R (2)
1
2
3
4
5
6
7
8
9
n-C4H9
n-C4H9
CH3
6a
6b
6c
6d
6e
6f
6e
6g
6h
6i
CH3 (2a )
CH3 (2a )
CH3 (2a )
n-C4H9 (2c)
CH3 (2a )
CH3 (2a )
i-C3H7 (2b)
CH3 (2a )
CH3 (2a )
CH3 (2a )
CH3 (2a )
CH3 (2a )
2
3.5
2
2
2
2.5
10
4
86 (7a , 100/0)
79 (7b, >99/1)
82 (7c, 100/0)
80 (7d , >99/1)
79 (7e, 100/0)
75 (7f, 100/0)
78 (7g, >98/2)
70 (7h , 91/9)
67 (7i, 80/20)
0 7j
C2H5
C2H5
CH3
CH3
C2H5
CH3
C6H5
p-MeO-C6H4
C6H5
C2H5
C2H5
n-C5H11
n-C5H11
n-C6H13
n-C6H13
n-C6H13
n-C4H9
n-C4H9
4
1
1
1
0
1
2
pyridine
THPOCH2
THPOCH2
48
48
48
6j
6k
0 7k
0 7l
a
A mixture of 6 (1 mmol), PdCl2 (9 mg, 0.05 mmol), CuCl2 (405 mg, 3 mmol), and alcohol (0.8 mL) in 10 mL of benzene was stirred
b
under 1 atm of carbon monoxide at room temperature. Isolated yield based on 6 used, and the ratio of Z/E was determined by 300 MHz
H NMR spectra.
1
Sch em e 2
Sch em e 3
selenides reacted highly regio- and stereoselectively with
CuCl in CO to afford Z-6a , Z-6b, Z-6c, Z-6d , Z-6e, Z-6f,
2
and Z-6g in high yields (Table 3, entries 1, 2, 3, 4, 5, 6,
1
and 7). When R ) aryl, the reactions were slower with
lower stereoselectivities (Table 3, entries 8 and 9). In the
case of the acetylenic selenides substituted by a pyridine
2
group (Table 3, entry 10) and THPOCH group (Table 3,
attacks the acetylenic carbon with the higher electron
density,17 which determines the regioselectivity of halo-
palladation. In this case, palladium attacks the carbon
bonding with selenium. Vinylpalladium intermediates 12
is formed by chloropalladation of the carbon-carbon
entries 11 and 12), no chlorocarbonylation products were
formed possibly due to the coordination of the hetereo-
atom with palladium.
Two mechanisms for the reaction are proposed. One
is the alkoxycarbonyl palladation chlorination mecha-
nism and the other is the chloropalladation carbonylation
mechanism. Heck reported that 3-chloro-2-enoates were
formed as byproducts in the dicarboxylation reaction of
1
8
triple bond in the presence of CuCl
nated carbon monoxide reacted with R OH to afford
-alkylalkoxylcarbonylpalladium, intermediates (Z)-13
and (E)-13, which afford the final products (E)-3 or (Z)-7
and Pd(0). CuCl oxidizes the palladium(0) to regenerate
2
.
Then Pd-coordi-
2
1
1
6
1
-phenyl-1-propyne and 3,3-dimethyl-1-butyne. If the
former mechanism would be operative, the reaction of
acetylenic selenides with alcohols in the presence of PdCl
and CuCl under carbon monoxide should give the
2
the active divalent palladium species to finish the
catalytic cycle.
2
2
dicarbonylation product 11 as the byproduct. The forma-
tion of the dicarbonylation products has not been ob-
served. Therefore, the alkoxycarbonyl palladation chlo-
rination mechanism was eliminated (Scheme 2).
A chloropalladation carbonylation mechanism for this
reaction is proposed as shown in Scheme 3. Palladium
In conclusion, the methodology discussed in this paper
provides an efficient and general high yield route to
2-seleno-3-chloroacrylates with high regio- and stereo-
selectivity under mild conditions. Although a possible
mechanism has been provided, it remains unclear why
(
17) Kaneda, K.; Uchiyama, T.; Fujiwara, Y.; Imanaka, T.; Teranishi,
(
15) Gavina, F.; Luis, S. V.; Ferrer, P. Costero, A. M.; Marco, J . A.
J . Chem. Soc., Chem. Commun. 1985, 297.
16) Heck, R. F. J . Am. Chem. Soc. 1972, 94, 2712.
S. J . Org. Chem. 1979, 44, 55.
(18) (a) Ma, S.; Lu, X. J . Org. Chem. 1993, 58, 1245. (b) Lu, X.; Zhu,
G. Synlett 1993, 68.
(

6
564 J . Org. Chem., Vol. 65, No. 20, 2000
Huang and Sun
1
the reactions of 2-phenylethynyl selenides afforded (E)-
-seleno-3-chloro-3-phenylacrylates while the reactions
(82%) of E-3e. Liquid. H NMR δ 0.95 (d, J ) 6.28 Hz, 6H),
.48 (t, J ) 7.49 Hz, 3H), 2.85 (q, J ) 7.50 Hz, 2H), 4.75-4.91
m, 1H), 7.25-7.52 (m, 5H); 13C NMR δ 15.613, 20.704, 21.258,
1
(
2
of 2-alkylethynyl selenides gave (Z)-2-seleno-3-chloro-3-
alkylacrylates. Due to the ease of converting the carbon-
chlorine bond, the carbon-selenium bond, and the car-
bon-carbon double bond to other functional groups,19 this
methodology will be useful in the synthesis of stereodefi-
nite compounds, such as sterically hindered substituted
enoates, substituted allylic alcohols, etc.
6
1
1
9.734, 125.100, 128.125, 128.231, 129.117, 134.755, 138.217,
65.171; MS (m/z) 332 (M ( Cl), 100); IR (neat) 762, 1486,
716 cm . Anal. Calcd for C14H17ClO Se: C, 50.69; H, 5.17.
2
Found, C, 50.88; H, 5.25.
n -Bu tyl (E)-2-Eth ylselen o-3-ch lor o-3-p h en yla cr yla te
(E-3f). Starting from 2-phenylethynyl ethyl selenide 1b (209
+
35
-1
mg, 1 mmol) and n-butyl alcohol (0.8 mL) to afford 304 mg
1
(
88%) of E-3f. Liquid. H NMR δ 0.85 (t, J ) 7.23 Hz, 3H),
0
3
7
1
.97-1.09 (m, 2H), 1.26-1.45 (m, 2H), 1.48 (t, J ) 7.51 Hz,
H), 2.87 (q, J ) 7.52 Hz, 2H), 3.90 (t, J ) 6.52 Hz, 2H), 7.24-
Exp er im en ta l Section
+
35
.45 (m, 5H); MS (m/z) 346 (M ( Cl), 100); IR (neat) 766, 1446,
Gen er a l. All H and 13C NMR spectra were recorded at 300
1
-
1
2
712 cm . Anal. Calcd for C15H19ClO Se: C, 52.11; H, 5.54.
Found, C, 52.28; H, 5.45.
p-Nitr oben zyl (E)-2-Eth ylselen o-3-ch lor o-3-ph en ylacr y-
la te (E-3g). Starting from 2-phenylethynyl ethyl selenide 1b
209 mg, 1 mmol) and p-nitrobenzyl alcohol (0.8 mL) to afford
MHz with CDCl
3 2
as solvent. CuCl was dried at 130 °C over
2 5
P O
. All other reagents were used directly as obtained
commercially.
Gen er a l P r oced u r e for th e Ch lor op a lla d a tion -Ca r -
bon yla tion of th e Acetylen ic Selen id es. To a mixture of
PdCl (0.05 mmol, 9 mg) and CuCl (3 mmol, 405 mg) in
2 2
benzene (10 mL) were added an alcohol (0.8 mL) and the
acetylenic selenide (1 or 6, 1 mmol) under 1 atm of carbon
monoxide at room temperature. After the reaction was com-
plete, as monitored by TLC (eluent: hexane/ethyl acetate )
(
2
55 mg (60%) of E-3g. Solid; mp 64-66 °C (from ethyl acetate-
1
hexanes). H NMR δ 1.48 (t, J ) 7.51 Hz, 3H), 2.85 (q, J )
7
7
(
.52 Hz, 2H), 5.10 (s, 2H), 6.98 (d, J ) 8.73 Hz, 2H), 7.28-
.45 (m, 5H), 8.05 (d, J ) 8.77 Hz, 2H); MS (m/z) 425
+
35
-1
M ( Cl), 83.16); IR (neat) 747, 1523, 1718 cm . Anal. Calcd
for C18
H, 3.91; N, 3.21.
4
H16NClO Se: C, 50.92; H, 3.80; N, 3.30. Found, C, 51.03;
1
0:1), the mixture was washed with brine and extracted with
ether. The combined ether layer was dried over MgSO
Filtration, evaporation, and chromatography on silica gel
4
.
Meth yl 2-P h en ylselen o-3-ch lor o-3-p h en yla cr yla te (3h ).
Starting from 2-phenylethynyl phenyl selenide 1d (257 mg, 1
mmol) and methanol (0.8 mL) to afford 264 mg (75%) of 3h .
The following data are discernible for Z-3h and E-3h , which
(
eluent: hexane/ethyl acetate ) 10:1) afforded the expected
products 3 or 7.
Meth yl (E)-2-Meth ylselen o-3-ch lor o-3-p h en yla cr yla te
1
cannot be separated by chromatography. Liquid; Z-3h : H NMR
(
E-3a ). Starting from 2-phenylethynyl methyl selenide 1a (195
1
3
7
7
.15 (s, 3H), 7.24-7.78 (m, 10H); E-3h : H NMR 3.50 (s, 3H),
mg, 1 mmol) and methanol (0.8 mL) to afford 276 mg (95%) of
+ 35
.24-7.78 (m, 10H); MS (m/z) 352 (M ( Cl), 100); IR (neat)
1
E-3a . Liquid; H NMR 2.31 (s, 3H), 3.52 (s, 3H), 7.25-7.48
-1
2
66, 1486, 1718 cm . Anal. Calcd for C16H13ClO Se: C, 54.65;
1
3
(
1
(
m, 5H); C NMR δ 6.766, 52.481, 124.957, 127.776, 128.358,
H, 3.73. Found, C, 54.96; H, 4.06.
Meth yl (Z)-2-Meth ylselen o-3-ch lor o-2-h ep ten oa te (Z-
a ). Starting from 2-butylethynyl methyl selenide 6a (175 mg,
28.653, 129.254, 133.785, 137.823, 165.852; MS (m/z) 290
M ( Cl), 96.56), 129 (100); IR (neat) 700, 1432, 1716 cm
+
35
-1
.
7
Anal. Calcd for C11 Se: C, 45.62; H, 3.83. Found, C,
H
11ClO
2
1
mmol) and methanol (0.8 mL) to afford 232 mg (86%) of Z-7a .
4
5.96; H, 4.06.
1
Liquid; H NMR 0.85 (t, J ) 7.32 Hz, 3H), 1.32-1.43 (m, 2H),
Meth yl (E)-2-Eth ylselen o-3-ch lor o-3-ph en ylacr ylate (E-
b). Starting from 2-phenylethynyl ethyl selenide 1b (209 mg,
1
(
.52-1.63 (m, 2H), 2.16 (s, 3H), 2.49 (t, J ) 7.35 Hz, 2H), 3.80
3
13
s, 3H); C NMR δ 6.4, 12.4, 21.8, 28.5, 37.6, 52.5, 121.9, 140.2,
1
mmol) and methanol (0.8 mL) to afford 283 mg (93%) of E-3b.
+ 35
1
1
64.5. MS (m/z) 270 (M ( Cl), 100); IR (neat) 1378, 1432, 1602,
1
Solid, mp 37-38 °C (from ethyl acetate-hexanes); H NMR
-1
9 2
718 cm . Anal. Calcd for C H15ClO Se: C, 40.09; H, 5.61.
Found, C, 39.73; H, 5.65.
Meth yl (Z)-2-Eth ylselen o-3-ch lor o-2-h ep ten oa te (Z-7b).
Starting from 2-butylethynyl ethyl selenide 6b (189 mg, 1
mmol) and methanol (0.8 mL) to afford 224 mg (79%) of Z-7b.
δ 1.46 (t, J ) 7.51 Hz, 3H), 2.85 (q, J ) 7.50 Hz, 2H), 3.51 (s,
3
1
H), 7.25-7.42 (m, 5H); 13C NMR δ 15.0, 21.9, 52.8, 124.5,
27.8, 128.1, 129.7, 135.2, 137.9, 166.2; MS (m/z) 304
+
35
-1
(
M ( Cl), 96.56), 129 (100); IR (neat) 766, 1486, 1718 cm
Anal. Calcd for C12 Se: C, 47.37; H, 4.28. Found, C,
7.61; H, 4.40.
Meth yl (E)-2-Isop r op ylselen o-3-ch lor o-3-p h en yla cr y-
la te (E-3c). Starting from 2-phenylethynyl isopropyl selenide
c (223 mg, 1 mmol) and methanol (0.8 mL) to afford 286 mg
90%) of E-3c. Solid, mp34-36 °C (from ethyl acetate-
.
H
13ClO
2
1
Liquid; H NMR 0.85 (t, J ) 7.32 Hz, 3H), 1.31-1.45 (m, 5H),
4
1
.53-1.67 (m, 2H), 2.49 (t, J ) 7.32 Hz, 2H), 2.79 (q, J ) 7.51
+ 35
Hz, 2H), 3.83 (s, 3H); MS (m/z) 284 (M ( Cl), 45.33), 223 (100);
-1
IR (neat) 1436, 1598, 1718 cm . Anal. Calcd for C10
Se: C, 42.35; H, 6.04. Found, C, 42.60; H, 5.94.
Meth yl (Z)-2-Eth ylselen o-3-ch lor o-2-octen oa te (Z-7c).
Starting from 2-pentyl-ethynyl ethyl selenide 6c (203 mg, 1
mmol) and methanol (0.8 mL) to afford 244 mg (82%) of Z-7c.
2
H17ClO -
1
(
1
hexanes); H NMR δ 1.55 (d, J ) 6.85 Hz, 6H), 3.55-3.70 (m,
4
1
H), 7.35-7.50 (m, 5H); 13C NMR δ 24.344, 34.442, 52.521,
24.219, 127.862, 128.317, 129.347, 137.995, 138.124, 167.034;
1
Liquid; H NMR 0.87 (t, J ) 6.82 Hz, 3H), 1.40-1.32 (m, 4H),
+
35
MS (m/z) 318 (M ( Cl), 30.99), 216 (100); IR (neat) 698, 1253,
1
1
.45 (t, J ) 7.52 Hz, 3H), 1.54-1.68 (m, 2H), 2.50 (t, J ) 6.65
-
1
723 cm . Anal. Calcd for C13
H
15ClO
2
Se: C, 49.13; H, 4.72.
13
Hz, 2H), 2.84 (q, J ) 7.53 Hz, 2H), 3.79 (s, 3H); C NMR δ
Found, C, 49.38; H, 4.85.
1
6.1, 18.4, 22.3, 23.5, 30.0, 32.9, 40.5, 53.5, 122.1, 143.5, 168.5.
Eth yl (E)-2-Eth ylselen o-3-ch lor o-3-p h en yla cr yla te (E-
d ). Starting from 2-phenylethynyl ethyl selenide 1b (209 mg,
+ 35
MS (m/z) 298 (M ( Cl), 60.62), 93 (100); IR (neat) 1378, 1596,
721 cm . Anal. Calcd for C11
Found, C, 44.47; H, 6.43.
n -Bu tyl (Z)-2-Meth ylselen o-3-ch lor o-2-octen oa te (Z-
d ). Starting from 2-pentyl-ethynyl methyl selenide 6d (189
3
-1
1
2
H19ClO Se: C, 44.38; H, 6.43.
1
mmol) and ethanol (0.8 mL) to afford 239 mg (75%) of E-3d .
1
Liquid. H NMR δ 0.95 (t, J ) 7.14 Hz, 3H), 1.45 (t, J ) 7.49
Hz, 3H), 2.85 (q, J ) 7.51 Hz, 2H), 4.01 (q, J ) 7.14 Hz, 2H),
7
7
1
.41-7.30 (m, 5H); 13C NMR δ 13.689, 15.535, 20.903, 61.740,
mg, 1 mmol) and n-butyl alcohol (0.8 mL) to afford 261 mg
24.801, 127.969, 128.257, 129.198, 135.093, 138.109, 165.683;
1
(
80%) of Z-7d . Liquid; H NMR 0.81-0.99 (m, 6H), 1.21-1.50
+
35
-1
MS (m/z) 318 (M ( Cl), 100); IR (neat) 766, 1444, 1714 cm
Anal. Calcd for C13 Se: C, 49.15; H, 4.76. Found, C,
8.83; H, 4.73.
Isop r op yl (E)-2-Eth ylselen o-3-ch lor o-3-p h en yla cr yla te
E-3e). Starting from 2-phenylethynyl ethyl selenide 1b (209
mg, 1 mmol) and isopropyl alcohol (0.8 mL) to afford 272 mg
.
(
2
2
m, 6H), 1.55-1.75 (m, 4H), 2.15 (s, 3H), 2.45 (t, J ) 7.13 Hz,
H
15ClO
2
+ 35
H), 4.19 (t, J ) 6.69 Hz, 2H); MS (m/z) 326 (M ( Cl), 58.02),
4
-1
53 (100); IR (neat) 1242, 1604, 1716 cm . Anal. Calcd for
C
13
H
23ClO
2
Se: C, 47.94; H, 7.12. Found, C, 48.17; H, 7.11.
Meth yl (Z)-2-Meth ylselen o-3-ch lor o-2-n on en oa te (Z-
e). Starting from 2-hexylethynyl methyl selenide 6e (203 mg,
(
7
1
mmol) and methanol (0.8 mL) to afford 235 mg (79%) of Z-7e.
1
Liquid; H NMR 0.85 (t, J ) 6.40 Hz, 3H), 1.31-1.42 (m, 6H),
1.52-1.60 (m, 2H), 2.15 (s, 3H), 2.49 (t, J ) 7.42 Hz, 2H), 3.85
(
19) Hercsi, L.; Heimaus, B.; Allard, C. Tetrahedron Lett. 1994, 35,
6
729.

Stereoselective Synthesis of 2-Seleno-3-chloroacrylates
s, 3H); 13C NMR δ 6.698, 14.030, 22.472, 27.643, 28.202,
J . Org. Chem., Vol. 65, No. 20, 2000 6565
(
DIBAL-H (1.0 mmol) in THF (5 mL) was stirred at room
temperature for about 3 h. Then methanol (1.5 mmol) was
added to the mixture. The resulting mixture was stirred for
20 min and filtered. The filtrate was washed with saturated
3
2
1.427, 38.072, 52.453, 121.408, 141.160, 165.973; MS (m/z)
+
35
98 (M ( Cl), 87.25), 209 (100); IR (neat) 1439, 1590, 1721
-1
cm . Anal. Calcd for C11
C, 44.65; H, 6.50.
2
H19ClO Se: C, 44.38; H, 6.43. Found,
aq NH
over MgSO
4
Cl to destroy the excess DIBAL-H, separated, and dried
. Evaporation of the solvent and chromatography
Meth yl (Z)-2-Eth ylselen o-3-ch lor o-2-n on en oa te (Z-7f).
Starting from 2-hexyl-ethynyl ethyl selenide 6f (217 mg, 1
mmol) and methanol (0.8 mL) to afford 234 mg (75%) of Z-7f.
4
on silica gel (hexane/ethyl acetate ) 5:1) afforded 216 mg (80%)
1
of Z-9c: liquid; H NMR 0.85 (t, J ) 6.82 Hz, 3H), 1.30-1.42
1
Liquid; H NMR 0.90 (t, J ) 6.80 Hz, 3H), 1.19-1.35 (m, 6H),
(m, 4H), 1.45 (t, J ) 7.5 Hz, 3H), 1.59-1.72 (m, 2H), 2.12 (s,
1H), 2.52 (t, J ) 7.50 Hz, 2H), 2.84 (q, J ) 7.42 Hz, 2H), 4.35
1
.40 (t, J ) 7.50 Hz, 3H), 1.59-1.66 (m, 2H), 2.51 (t, J ) 7.42
13
+ 35
Hz, 2H), 2.85 (q, J ) 7.50 Hz, 2H), 3.85 (s, 3H); C NMR δ
(s, 2H); MS (m/z) 270 (M ( Cl), 100); IR (neat) 2924, 3376
-
1
6
6
9
.489, 14.027, 21.899, 22.494, 27.700, 28.405, 31.532, 38.044,
cm . Anal. Calcd for C10
C, 44.87; H, 7.49.
H19ClOSe: C, 44.54; H, 7.1. Found,
+
35
9.727, 121.903, 139.596, 164.938; MS (m/z) 312 (M ( Cl),
3.74), 223 (100); IR (neat) 1431, 1597, 1722 cm-1. Anal. Calcd
(Z)-2-E t h ylselen o-3-ch lor o-2-n on a len -1-ol (Z-9f) was
prepared similarly: starting from Z-7f (312 mg, 1 mmol) to
2
for C12H21ClO Se: C, 46.24; H, 6.79. Found, C, 46.18; H, 6.88.
Isop r op yl (Z)-2-Meth ylselen o-3-ch lor o-2-n on en oa te (Z-
g). Starting from 2-hexylethynyl methyl selenide 6e (203 mg,
afford 224 mg (79%) of Z-9f. Liquid; H NMR 0.85 (t, J ) 6.60
1
7
Hz, 3H), 1.35-1.25 (m, 6H), 1.45 (t, J ) 7.45 Hz, 3H), 1.55-
1.70 (m, 2H), 2.03 (s, 1H), 2.55 (t, J ) 7.46 Hz, 2H), 2.90 (q,
1
mmol) and isopropyl alcohol (0.8 mL) to afford 254 mg (78%)
1
+ 35
of Z-7g. Liquid; H NMR 0.84 (t, J ) 6.82 Hz, 3H), 1.29-1.37
J ) 7.40 Hz, 2H), 4.35 (s, 2H); MS (m/z) 284 (M ( Cl), 100);
(
m, 12H), 1.62-1.68 (m, 2H), 2.28 (s, 3H), 2.47 (t, J ) 7.47
IR (neat) 2920, 3373 cm-1. Anal. Calcd for C H ClOSe: C,
1
1
21
+
35
Hz, 2H), 5.15-5.20 (m, 1H); MS (m/z) 326 (M ( Cl), 100); IR
(
46.57; H, 7.46. Found, C, 46.75; H, 7.40.
-(p-Meth oxyp h en yl)selen o-3-ch lor o-2-h ep ten -1-ol (9i)
-
1
neat) 1435, 1596, 1720 cm . Anal. Calcd for C13
2
H23ClO Se:
2
C, 47.94; H, 7.12. Found, C, 48.18; H, 7.08.
was prepared similarly: starting from 7i (362 mg, 1 mmol) to
afford 200 mg (60%) of Z-9i and 63 mg (19%) of E-9i.
Met h yl 2-P h en ylselen o-3-ch lor o-2-h ep t en oa t e (7h ).
Starting from 2-butylethynyl phenyl selenide 6g (237 mg, 1
mmol) and methanol (0.8 mL) to afford 232 mg (70%) of 7h .
1
Z-9i: Liquid; H NMR 0.85 (t, J ) 7.28 Hz, 3H), 1.23-1.30
(
2
(
5
1
3
m, 2H), 1.45(s, 1H), 1.51-1.70 (m, 2H), 2.53 (t, J ) 7.46 Hz,
The following data are discernible for Z-7h and E-7h , which
H), 3.75 (s, 3H), 4.10 (s, 2H), 6.77 (d, J ) 8.82 Hz, 2H), 7.55
1
cannot be separated by chromatography. Liquid; Z-7h :
H
13
d, J ) 8.84 Hz, 2H); C NMR δ 13.873, 21.924, 30.344, 36.160,
NMR 0.89 (t, J ) 7.26 Hz, 3H), 1.29-1.40 (m, 2H), 1.55-1.70
5.328, 60.679, 115.200, 117.576, 130.573, 135.039, 136.354,
(
5
m, 2H), 2.51 (t, J ) 7.31 Hz, 2H), 3.30 (s, 3H), 7.25-7.61 (m,
+ 35
37.893, 160.430; MS (m/z) 334 (M ( Cl), 100); IR (neat) 2958,
1
H); (E)-7h : H NMR 0.89 (t, J ) 7.26 Hz, 3H), 1.29-1.40
-1
2
373 cm . Anal. Calcd for C14H19ClO Se: C, 50.39; H, 5.74.
Found, C, 50.67; H, 5.57.
(
3
7
m, 2H), 1.55-1.70 (m, 2H), 2.71 (t, J ) 7.51 Hz, 2H), 3.55 (s,
+
35
H), 7.25-7.61 (m, 5H); MS (m/z) 332 (M ( Cl), 100); IR (neat)
1
1
E-9i: H NMR 0.85 (t, J ) 7.28 Hz, 3H), 1.24-1.38 (m, 2H),
.55-1.79 (m, 3H), 2.79 (t, J ) 7.50 Hz, 2H), 3.85 (s, 3H), 4.30
-
2
47, 1474, 1715 cm . Anal. Calcd for C14H17ClO Se: C, 50.70;
1
(
H, 5.17. Found, C, 51.02; H, 5.05.
s, 2H), 6.82 (d, J ) 8.78 Hz, 2H), 7.49 (d, J ) 8.83 Hz, 2H);
Met h yl 2-(p -m et h oxyp h en yl)selen o-3-ch lor o-2-h ep -
ten oa te (7i) Starting from 2-butylethynyl (p-methoxy)phenyl
selenide 6i (267 mg, 1 mmol) and methanol (0.8 mL) to afford
+
35
-1
MS (m/z) 334 (M ( Cl), 100); IR (neat) 2950, 3376 cm . Anal.
Calcd for C14
H, 5.58.
2
H19ClO Se: C, 50.39; H, 5.74. Found, C, 50.77;
2
43 mg (67%) of 7i. The following data are discernible for Z-7i
and E-7i, which cannot be separated by chromatography.
Liquid; Z-7i: H NMR 0.80 (t, J ) 7.26 Hz, 3H), 1.25-1.42
1
Ack n ow led gm en t. We thank the National Natural
Science Foundation of China for financial support. We
also thank Dr. Shengming Ma for helpful discussion.
(
3
m, 2H), 1.55-1.67 (m, 2H), 2.51 (t, J ) 7.30 Hz, 2H), 3.35 (s,
H), 3.80 (s, 3H), 6.82 (d, J ) 10.04 Hz, 2H), 7.53 (d, J ) 10.02
1
Hz, 2H); E-7i: H NMR 0.80 (t, J ) 7.26 Hz, 3H), 1.25-1.42
m, 2H), 1.55-1.67 (m, 2H), 2.71 (t, J ) 7.50 Hz, 2H), 3.55 (s,
H), 3.80 (s, 3H), 6.82 (d, J ) 10.04 Hz, 2H), 7.53 (d, J ) 10.02
(
3
1
Su p p or tin g In for m a tion Ava ila ble: The H NMR spectra
of the compounds E-3a , E-3b, E-3c, E-3d , E-3e, E-3f, E-3g,
1
3
Hz, 2H); C NMR δ 13.748, 21.669, 29.814, 37.709, 52.123,
5
1
cm . Anal. Calcd for C15
C, 49.77; H, 5.27.
3
h , Z-7a , Z-7b, Z-7c, Z-7d , Z-7e, Z-7f, Z-7g, 7h , 7i, Z-9c, Z-9f,
5.280, 114.659, 117.434, 124.555, 137.838, 138.647, 160.385,
13
Z-9i, and E-9i; C NMR spectra of the compounds E-3a , E-3b,
+
35
65.331; MS (m/z) 362 (M ( Cl), 100); IR (neat) 674, 1717
1
1
E-3c, E-3d , E-3e, Z-7a , Z-7c, Z-7e, Z-7f, 7i, and Z-9i; H- H
NOSEY spectra of compounds Z-9c, Z-9i, and E-9i. This
material is available free of charge via the Internet at
http://pubs.acs.org.
-1
3
H19ClO Se: C, 49.81; H, 5.29. Found,
P r ep a r a tion of (Z)-2-Eth ylselen o-3-ch lor o-2-octen -1-ol
Z-9c). Typ ica l P r oced u r e. A mixture of methyl (Z)-2-
(
ethylseleno-3-chloro-2-octenoate (Z-7c) (1 mmol, 298 mg) and
J O0006977