Silyl Formates as Surrogates of Hydrosilanes and Their Application in the Transfer Hydrosilylation of Aldehydes

Silyl formates are investigated for the first time as surrogates of hydrosilanes. In the presence of a well-defined ruthenium catalyst, these reagents are shown to promote the chemoselective reduction of a variety of aldehydes by transfer hydrosilylation. Mechanistic investigations have shown that genuine hydrosilane species are avoided during catalysis. The mechanism involves a sequence of decarboxylation/insertion/transmetallation steps.