Hydrosilylation of Alkynes with a Cationic Rhodium Species Formed in an Anionic Micellar System
摘要:
Rhodium-catalyzed hydrosilylation of alkynes in an aqueous micellar system has been developed. A combination of [RhCl(nbd)](2) and bis(diphenylphosphino)propane (dppp) effects (E)-selective hydrosilylation in the presence of sodium dodecyl sulfate (SDS) in water. The (E)selectivity strongly indicates the formation of a cationic rhodium species via dissociation of the Rh-Cl bond by the action of anionic micelles. The addition of sodium iodide provided (Z)-alkenylsilanes predominantly.
A Selective Synthesis of (E)-Vinylsilanes by Cationic Rhodium Complex-Catalyzed Hydrosilylation of 1-Alkynes and Tandem Hydrosilylation/Isomerization Reaction of Propargylic Alcohols to .beta.-Silyl Ketones
作者:Ryo Takeuchi、Shuichi Nitta、Dai Watanabe
DOI:10.1021/jo00115a020
日期:1995.5
(E)-Vinylsilanes were obtained with high selectivities by [Rh(COD)(2)]BF4/2PPh(3)-catalyzed hydrosilylation of 1-alkynes with triethylsilane. A wide range of 1-alkynes were used. The hydrosilylation of propargylic alcohols with triethylsilane gave (E)-gamma-silyl allylic alcohols 2h-r, a useful source of a chiral alcohol, with high selectivities in excellent yields. The reaction can be carried out without protecting the alcohol functionality. The resulting (E)-gamma-silyl allylic alcohols could be transformed into beta-silyl ketones. The isomerization was also catalyzed by [Rh(COD)(2)]BF4/2PPh(3). Furthermore, the tandem hydrosilylation-isomerization of secondary propargylic alcohols could be carried out in a one-pot procedure.
(E)-丙二烯二硅烷通过使用[Rh(COD)(2)]BF4/2PPh(3)协同催化的水硅化反应获得了高选择性,适用于多种一元炔烃底物。丙炔醇的水硅化反应产生γ-硅基 allylic 醇2h-R,并提供了一种高效产率的构象选择性高的旋多糖醇。该反应无需保护醇的功能性即可进行。由此产生的(E)-γ-硅基 allylic 醇可以通过转化得到β-硅基酮。此外,该[Rh(COD)(2)]BF4/2PPh(3)催化还可以催化丙炔醇的同分异构化反应。Furthermore, a one-pot tandem hydrosilylation-isomerization of secondary propargylic alcohols can be achieved using this approach.
Hydrosilylation of Alkynes with a Cationic Rhodium Species Formed in an Anionic Micellar System
Rhodium-catalyzed hydrosilylation of alkynes in an aqueous micellar system has been developed. A combination of [RhCl(nbd)](2) and bis(diphenylphosphino)propane (dppp) effects (E)-selective hydrosilylation in the presence of sodium dodecyl sulfate (SDS) in water. The (E)selectivity strongly indicates the formation of a cationic rhodium species via dissociation of the Rh-Cl bond by the action of anionic micelles. The addition of sodium iodide provided (Z)-alkenylsilanes predominantly.