Synlett 2002(7): 1167-1169
DOI: 10.1055/s-2002-32609
LETTER
© Georg Thieme Verlag Stuttgart · New York

[Rh(OH)(cod)]2 (cod = 1,5-Cyclooctadiene): A Highly Efficient Catalyst for 1,4-Hydrosilylation of α,β-Unsaturated Carbonyl Compounds

Atsunori Mori*, Tsuyoshi Kato
Chemical Resources Laboratory, Tokyo Institute of Technology, Nagatsuta, Yokohama 226-8503, Japan
Fax: +81(45)9245224; e-Mail: amori@res.titech.ac.jp;
Further Information

Publication History

Received 7 May 2002
Publication Date:
07 February 2007 (online)

Abstract

[Rh(OH)(cod)]2 (cod: 1,5-cyclooctadiene) is found to be a highly efficient catalyst for 1,4-hydrosilylation of α,β-unsaturated carbonyl compounds leading to enolsilanes. The reaction of 2-cyclohexen-1-one with HSiMe(OEt)2 in the presence of 0.005 mol% of the catalyst without solvent furnishes the corresponding enolsilane in 97% yield at room temperature within 10 min.

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The mixture of 2-cyclohexen-1-one (2, 10 mmol) and HSi(OEt)Me2 (11 mmol) in the presence of [Rh(OH)(cod)]2 (1 mg, 0.005 mol%) was stirred at room temperature for 10 min under an argon atmosphere. The resulting mixture was subjected to bulb-to-bulb distillation under 0.5 Torr at 55 °C (bath temp) to afford 1.95 g of (1-cyclohexnenyl)ethoxy(dimethyl)silane (97%) as a colorless liquid. 1H NMR (CDCl3, 300 MHz) δ 0.18 (s, 6 H), 1.22 (t, J = 7.2 Hz, 3 H), 1.42-1.60 (m, 2 H), 1.61-1.76 (m, 2 H), 1.94-2.14 (m, 4 H), 3.79 (q, J = 7.2 Hz, 2 H), 4.94-4.98 (m, 1 H).