Platinum-Catalyzed Addition of Silylenes to β-Methyl α,β-Unsaturated Ketones: Formation of 1-Oxa-2-sila-5-cyclohexenes

摘要

It is well-documented that silylenes (divalent silicon species, R2Si:) are very active intermediates which react with various types of compounds giving tetravalent organosilanes. However, the use of silylenes for organic synthesis had not been extensively studied before Woerpel reported a silver-catalyzed silylene transfer reaction to alkenes giving silacyclopropanes with high selectivity. Among several reported methods of generating silylenes, we became interested in transition metal-catalyzed reaction of hydrodisilanes generating silylenes together with hydrosilanes, because of their mild reaction conditions and the ready availability of the hydrodisilanes. Here we wish to report that dimethylsilylene generated from pentamethyldisilane under the catalysis by a platinum complex is incorporated into α,β-unsaturated ketones giving two types of addition products depending on the substitution pattern at the β-position.