J. Am. Chem. Soc. 2001, 123, 2899-2900
Table 1. Phenylthioesterification of Terminal Alkynesa
2899
Palladium-Catalyzed Thioesterification of Alkynes
with O-Methyl S-Phenyl Thiocarbonate
Ruimao Hua,† Hideaki Takeda,§ Shun-ya Onozawa,†
Yoshimoto Abe,§ and Masato Tanaka*,†,§
R
c
product
3a
3b
3c
3d
% yieldb
selectivityb
National Institute of Materials and Chemical Research
Tsukuba, Ibaraki 305-8565, Japan
Department of Industrial Chemistry
Science UniVersity of Tokyo, Noda, Chiba 278-8510, Japan
n-C6H13
86
96
32
41
86
73
98
94
98
95
94
c
n-C4H9
c,d
CH3
t-C4H9
c
ReceiVed NoVember 27, 2000
t-BuMe2Si(CH2)4
3e
3f
c
MeOCH2
84
The sulfur-to-carbon bond cleavage by metal complexes1-3 is
a research subject of considerable scrutiny. The majority of the
research, however, is related to either the mechanism of desulfu-
rization of oil2 or the cross-coupling reaction with nucleophiles
such as Grignard reagents.3 We wish to disclose that terminal
acetylenes (1) undergo an addition reaction with the S-C bond
in PhSCOOMe (2) (Table 1), an entirely new entry to the addition
reactions of heteroatom-containing bonds.4,5 The reaction furnishes
alkenyl sulfide linkages of versatile synthetic applicability.3
3-Organothio-2-alkenoic acid esters in particular have been
involved as key intermediates in synthetic sequences of biologi-
cally important molecules.6
When 2 (202.0 mg, 1.2 mmol) was added to a suspension of
Pd(PCy3)2 (27.0 mg, 0.04 mmol) in octane (2 mL), the mixture
immediately became a pale-red homogeneous solution. 1-Octyne
(1a, 147 µL, 1.0 mmol) was then added and the resulting mixture
was stirred at 110 °C over 20 h under N2. GC-MS and GC
analyses of the reaction mixture revealed the formation of methyl
(Z)-3-phenylthio-2-nonenoate (3a)7 in 86% (based on 1a; 98%
regio- and stereoselectivity),8 (Z)-1,2-bis(phenylthio)-1-octene (4a;
2%, based on 1a),9 PhSMe (4%, based on 2 used), and dimethyl
(HO)Me2C
Cl(CH2)3
NC(CH2)3
C6H5CH2
C6H5
p-MeOC6H4
p-FC6H4
3g
3h
73
62
81
35 (+63)
62
63
55
100
98
62
3i
3j (+3j′)e
3k
3l
3m
97
97
94
a The reactions were carried out at 110 °C for 20 h by using 1.0
mmol of alkynes, 1.2 mmol of methyl phenylthiocarbonate 2, and 0.04
mmol of Pd(PCy3)2 in a mixture solvent of 0.5 mL of toluene and 1.5
mL of n-octane. b GC yield based on the alkynes used, with the
selectivity determined by GC. c The reaction was performed in n-octane.
d Propyne: 1 atm, yield based on 2 used. e 3j′ ) methyl 3-phenylthio-
4-phenyl-3-butenoate.
carbonate (2%, based on 1a). Evaporation followed by column
chromatography on silica gel with hexane as eluent led to isolation
of 3a (71%) as a colorless oil.
The formation of PhSMe is due most likely to the phosphine-
catalyzed decarboxylation.10 On the other hand, byproduct 4a
appears to have come from (PhS)2Pd species, generation of which
presumably is relevant to the dimethyl carbonate formation (vide
infra). In practice, careful GC and GC-MS analyses of a PdMe2-
[Ph2P(CH2)4PPh2]-catalyzed reaction,11 which formed a relatively
large quantity of 4a (21% yield, 0.21 mmol), revealed that nearly
the same quantity of dimethyl carbonate (0.23 mmol) was also
formed.
† National Institute of Materials and Chemical Research.
§ Science University of Tokyo.
(1) (a) Osakada, K.; Maeda, M.; Nakamura, Y.; Yamamoto, T.; Yamamoto,
A. J. Chem. Soc., Chem. Commun. 1986, 442. (b) Kuniyasu, H.; Ohtaka, A.;
Nakazono, T.; Kinomoto, H.; Kurosawa, H. J. Am. Chem. Soc. 2000, 122,
2375.
(2) For reactions of thiophenes with transition metal complexes, see: (a)
Angelici, R. J. Acc. Chem. Res. 1988, 21, 387. (b) Angelici, R. J. Coord.
Chem. ReV. 1990, 105, 61. See also: (c) Paneque, M.; Taboada, S.; Carmona,
E. Organometallics 1996, 15, 2678. (d) Bianchini, C.; Frediani, P.; Herrera,
V.; Jime´nez, M. V.; Meli, A.; Rinco´n, L.; Sa´nchez-Delgado, R.; Vizza, F. J.
Am. Chem. Soc. 1995, 117, 4333. (e) Garcia, J. J.; Maitlis, P. M. J. Am. Chem.
Soc. 1993, 115, 12200. (f) Jones, W. D.; Chin, R. M.; Crane, T. W.; Baruch,
D. M. Organometallics 1994, 13, 4448. (g) Druker, S. H.; Curtis, M. D. J.
Am. Chem. Soc. 1995, 117, 6366. (h) Smith, V. C. M.; Aplin, R. T.; Brown,
J. M.; Hursthouse, M. B.; Karalulov, A. I.; Malik. K. M. A.; Cooley, N. A.
J. Am. Chem. Soc. 1994, 116, 5180.
(3) For reviews on metal-assisted transformations of the C-S bond, see:
(a) Luh, T.-Y. Acc. Chem. Res. 1991, 24, 257. (b) Luh, T.-Y.; Leung, M.-K.;
Wong, K.-T. Chem. ReV. 2000, 100, 3187. See also: (c) Kobayashi, S.; Takei,
H.; Mukaiyama, T. Chem. Lett. 1973, 1097. (d) Okamura, H.; Miura, M.;
Takei, H. Tetrahedron Lett. 1979, 20, 43. (e) Okamura, H.; Takei, H.
Tetrahedron Lett. 1979, 3425. (f) Wenkert, E.; Ferreira, T. W.; Michelotti, E.
T. J. Chem. Soc., Chem. Commun. 1979, 637. (g) Trost, B. M.; Ornstein, P.
L. Tetrahedron Lett. 1981, 22, 3463. (h) Fiandanese, V.; Marchese, G.; Naso,
F.; Ronzini, L. J. Chem. Soc., Chem. Commun. 1982, 647. (i) Trost B. M.;
Lavoie, A. C. J. Am. Chem. Soc. 1983, 105, 5075. (j) Sugimura, H.; Takei,
H. Chem. Lett. 1984, 1505. (k) Fiandanese, V.; Marchese, G.; Naso, F.;
Ronzini, L. J. Chem. Soc., Parkin Trans. 1 1985, 1115. (l) Fiandanese, V.;
Marchese, G.; Naso, F.; Ronzini, L. J. Organomet. Chem. 1986, 312, 343.
(m) Fiandanese, V.; Marchese, G.; Naso, F.; Ronzini, L. Synthesis 1987, 1034.
(n) Fiandanese, V.; Marchese, G.; Mascolo, G.; Naso, F.; Ronzini, L.
Tetrahedron Lett. 1988, 29, 3705. (o) Carpita, A.; Rossi, R.; Scamuzzi, B.
Tetrahedron Lett. 1989, 30, 2699. (p) Babudri, F.; Fiandanese, V.; Mazzone,
L.; Naso, F. Tetrahedron Lett. 1994, 35, 8847.
Use of a polar solvent resulted in a lower yield of 3a to reveal
the following trends: hexane (87% yield of 3a) ≈ octane
(86%) > toluene (67%) g dioxane (62%) > dimethoxyethane
(52%) > CH3CN (23%) ≈ DMF (21%).11 The solvent effect
appears to be associated mainly with the decarboxylation of 2,
which proceeds more readily in polar solvents.10 Indeed, the extent
of the PhSMe formation increased as follows: hexane (6%) ≈
octane (4%) ≈ toluene (7%) < dimethoxyethane (38%) e dioxane
(43%) ≈ CH3CN (43%) < DMF (69%).
(6) (a) Kobayashi, S.; Mukaiyama, T. Chem. Lett. 1974, 705. (b) Dan-
ishefsky, S.; Harayama, T.; Singh, R. K. J. Am. Chem. Soc. 1979, 101, 7008.
(c) Kaydos, J.; Smith, D. L. J. Org. Chem. 1983, 48, 1096. (d) Habich D.;
Hartwig W. Tetrahedron 1984, 40, 3667. (e) Nishida, A.; Shibasaki, M.;
Ikegami, S. Chem. Pharm. Bull. 1986, 34, 1434. (f) Chan, T. H.; Prasad, V.
C. J. Org. Chem. 1986, 51, 3012. (g) Chan, T. H.; Prasad, V. C. J. Org.
Chem. 1987, 52, 110. (h) Mori, K.; Mori, H. Tetrahedron 1987, 43, 4097. (i)
Mori, K.; Fujiwhara, M. Tetrahedron 1988, 44, 343. (j) Mori, K.; Fujiwhara,
M. Liebigs Ann. Chem. 1988, 167. (k) Mori, K.; Fujiwhara, M. Liebigs Ann.
Chem. 1990, 369. (l) Chan, T. H.; Guertin, K. R.; Prasad, C. V. C.; Thomas,
A. W.; Strunz, G. M.; Salonius, A. Can. J. Chem. 1990, 68, 1170. (m)
Schwerdtfeger, A. E.; Chan, T. H. J. Org. Chem. 1993, 58, 6513. (n) Pereira,
O. Z.; Chan, T. H. J. Org. Chem. 1994, 59, 6710. (o) Kinoshita, Y.; Kitahara,
T. Tetrahedron Lett. 1997, 38, 4993.
(7) The structures of 3a and 3j′ were further confirmed by reduction to
the corresponding alcohols 3a-ol and 3j′-ol.
(4) Addition reactions of Se-COAr, Cl-COOR, and Sn-CONR2 have
been reported. (a) Zhao, C.-Q.; Huang, X.; Meng, J.-B. Tetrahedron Lett.
1998, 39, 1933. (b) Hua, R.; Shimada, S.; Tanaka, M. J. Am. Chem. Soc.
1998, 120, 12365. (c) Shirakawa, E.; Yamasaki, K.; Yoshida, H.; Hiyama, T.
J. Am. Chem. Soc. 1999, 121, 10221. (d) Hua, R.; Onozawa, S.-y.; Tanaka,
M. Organometallics 2000, 19, 3269.
(8) The cis addition was confirmed by an NOE experiment. Irradiation of
the triplet at 1.96 ppm due to the allylic protons resulted in an 8% enhancement
of the olefinic proton signal at 5.97 ppm.
(9) Compound 4a was identified with a separately prepared authentic
sample. See: Kuniyasu, H.; Ogawa, A.; Miyazaki, S.-I.; Ryu, I.; Kambe, N.;
Sonoda, N. J. Am. Chem. Soc. 1991, 113, 9796.
(10) Jones, F. N. J. Org. Chem. 1968, 33, 4290.
(11) See Supporting Information for the details.
(5) (a) Beletskaya, I.; Moberg, C. Chem. ReV. 1999, 99, 3435. (b) Han,
L.-B.; Tanaka, M. Chem. Commun. 1999, 395.
10.1021/ja004063t CCC: $20.00 © 2001 American Chemical Society
Published on Web 03/02/2001