Efficient cross-metathesis of vinylsilanes, carrying a large spectrum of different substituents at silicon, with various olefins in the presence of the first and second generation Grubbs catalyst and Hoveyda–Grubbs catalyst is described. On the basis of the results of equimolar reactions of vinylsilanes with ruthenium alkylidene complexes and experiments with deuterium-labelled reagents, a general
Investigation of the factors controlling the regioselectivity of the hydrosilylation of alkynes catalysed by trans-di-μ-hydridobis(tricylcohexylphosphine)bis(silyl)diplatinum complexes
作者:Constantinos A. Tsipis
DOI:10.1016/s0022-328x(00)93435-1
日期:1980.3
The hydrosilylation of terminal and internalalkynes and also of some hydroxy-alkynes catalysed by trans-di-μ-hydridobis(tricyclohexylphosphine)bis(silyl)diplatinum complexes is described. These diplatinum complexes are very efficient catalysts for such hydrosilylations; high yields (80–98%) can be obtained under mild conditions with a catalysts/reactant ratio of 10−4–10−5/1. Addition of hydrosilanes
Hydrosilylation of alkynes catalyzed by platinum on carbon
作者:Moni Chauhan、Brian Jay Hauck、Lindsay P Keller、Philip Boudjouk
DOI:10.1016/s0022-328x(01)01103-2
日期:2002.2
Hydrosilylation of terminal and internal alkynes with chlorosilanes, alkylsilanes, and alkoxysilanes catalyzed by platinum on carbon are discussed. The yields of the isolated vinylsilanes are high and the selectivity of the product depends on the silane used. Hydrosilylation of alkynes with chlorosilanes produced the beta-trans vinylsilanes, while alkyl and alkoxysilanes produced two or three vinylsilane isomers. The selectivity of the catalyst platinum on carbon is similar to Karstedt's catalyst in the reaction of phenylacetylene with triethylsilane or triethoxysilane. High resolution electron microscopy showed colloidal platinum to be present in these reactions. (C) 2002 Published by Elsevier Science B.V.
Dual Role of Silanol Groups in Cyclopropanation and Hiyama−Denmark Cross-Coupling Reactions
作者:Louis-Philippe B. Beaulieu、Lukas B. Delvos、André B. Charette
DOI:10.1021/ol1002863
日期:2010.3.19
Di-tert-butoxy(alkenyl)silanols serve as substrates in the Simmons-Smith cyclopropanation reaction furnishing the corresponding di-tert-butoxy(cyclopropyl)silanols, which may be included in a Hiyama-Denmark cross-coupling reaction. The silanol group bears two distinct roles as it provides a directing group during the cyclopropanation and mediates the transmetalation event in the cross-coupling. The nature of the ligands on the silicon atom had a profound effect on reactivity in the cross-coupling, whereby substituting the alkoxide groups for fluorides allowed for efficient cross-coupling.