LETTER Rhodium-catalyzed Conjugate Addition of the Silicone Reagent to , -Unsaturated Carbonyl Compounds
303
Typical Experimental Procedure for conjugate Addition of Or-
ganochlorosilanes to , -unsaturated Carbonyl Compounds
(representative as the Reaction of 8 and 5a): To a solution of po-
tassium carbonate (10.37 g, 75 mmol) in 40 mL of toluene and 10
mL of water was added phenylmethyldichlorosilane (8) (4.77 g, 25
mmol). After stirring the mixture at r.t. for 2 h, (E)-ethyl 3-phenyl-
propenoate (5a) (0.88 g, 5 mmol, [Rh(OH)(cod)]2 (70 mg, 0.15
mmol) and 10 mL of toluene were added. The resulting mixture was
stirred at 120 °C for 41 h. After cooling the mixture to r.t., the or-
ganic layer was separated and aq was extracted with diethyl ether
(20 mL 2). The combined organic layer was washed with 1 M HCl
(30 mL), sat. aq NaHCO3 (30 mL), and brine (30 mL). Removal of
the dried solvent with anhyd magnesium sulfate and chromatogra-
phy on silica gel (hexane/AcOEt = 10:1) afforded 1.23 g of ethyl
3,3-diphenylpropanoate (6a, 97%).9
(4) Mori, A.; Danda, Y.; Fujii, T.; Hirabayashi, K.; Osakada, K.
J. Am. Chem. Soc. 2001, 123, 10774.
(5) The related conjugate addition with boron and tin reagents:
(a) Sakai, M.; Hayashi, H.; Miyaura, N. Organometallics
1997, 16, 4229. (b) Sakuma, S.; Sakai, M.; Itooka, R.;
Miyaura, N. J. Org. Chem. 2000, 65, 5951. (c) Takaya, Y.;
Ogasawara, M.; Hayashi, T. J. Am. Chem. Soc. 1998, 120,
5579. (d) Senda, T.; Ogasawara, M.; Hayashi, T. J. Org.
Chem. 2001, 66, 6852. (e) Oi, S.; Moro, M.; Ono, S.; Inoue,
Y. Chem. Lett. 1998, 83. (f) Huang, T.; Meng, Y.;
Venkatraman, S.; Wang, D.; Li, C.-J. J. Am. Chem. Soc.
2001, 123, 7451. (g) Venkatraman, S.; Meng, Y.; Li, C.-J.
Tetrahedron Lett. 2001, 42, 4459.
(6) For Mizoroki–Heck-type reactions: (a) Hirabayashi, K.;
Nishihara, Y.; Mori, A.; Hiyama, T. Tetrahedron Lett. 1998,
39, 7893. (b) Hirabayashi, K.; Ando, J.; Nishihara, Y.; Mori,
A.; Hiyama, T. Synlett 1999, 99. (c) Hirabayashi, K.; Ando,
J.; Kawashima, J.; Nishihara, Y.; Mori, A.; Hiyama, T. Bull.
Chem. Soc. Jpn. 2000, 73, 1409. (d) Du, X.; Suguro, M.;
Hirabayashi, K.; Mori, A.; Nishikata, T.; Hagiwara, N.;
Kawata, K.; Okeda, T.; Wang, H. F.; Fugami, K.; Kosugi, M.
Org. Lett. 2001, 3, 3313. (e) Cho, C. S.; Uemura, S. J.
Organomet. Chem. 1994, 465, 85. (f) Cho, C. S.; Itotani, K.;
Uemura, S. J. Organomet. Chem. 1993, 443, 253.
Acknowledgement
This work was supported by a Grant-in-aid for Scientific Research
(No. 13650915) from Japan Society for the Promotion of Science.
References
(1) Mori, A.; Suguro, M. Synlett 2001, 845.
(g) Lautens, M.; Roy, A.; Fukuoka, K.; Fagnou, K.; Martín-
Matute, B. J. Am. Chem. Soc. 2001, 123, 5358.
(2) Available from Chisso Chemicals Co. Ltd.; MW = 2500-
2700. We thank Chisso Chemicals Co. Ltd. for kind
donation of silicone reagents.
(7) Although we described that the reaction of silanediol with -
substituted substrates did not occur (ref.4) under the reported
conditions, further optimization revealed to undergo the
conjugate addition of such substrates with silanediol
recently. These results will be described in due course.
(8) (a) Hagiwara, E.; Gouda, K.; Hatanaka, Y.; Hiyama, T.
Tetrahedron Lett. 1997, 38, 439. (b) Gouda, K.; Hagiwara,
E.; Hatanaka, Y.; Hiyama, T. J. Org. Chem. 1996, 61, 7232.
(9) All products were identical with authentic samples.
(3) (a) Hirabayashi, K.; Mori, A.; Kawashima, J.; Suguro, M.;
Nishihara, Y.; Hiyama, T. J. Org. Chem. 2000, 65, 5342.
(b) Hirabayashi, K.; Kawashima, J.; Nishihara, Y.; Mori, A.;
Hiyama, T. Org. Lett. 1999, 1, 299. (c) Denmark, S. E.;
Sweis, R. F. J. Am. Chem. Soc. 2001, 123, 643; and
references therein. (d) For a review: Organosilicon
Compounds in Cross-Coupling Reactions; Hiyami, T. 421.
In Metal-Catalyzed Cross-Coupling Reactions; Diederich,
F.; Stang, P. J., Eds.; Wiley-VCH: Weinheim, 1998.
Synlett 2002, No. 2, 301–303 ISSN 0936-5214 © Thieme Stuttgart · New York