Palladium-Catalyzed Oxidative Dehydrosilylation for Contra-Thermodynamic Olefin Isomerization.

We report a newly developed, palladium-catalyzed dehydrosilylation of terminal alkylsilanes that combines with chain-walking hydrosilylation to create a one-pot isomerization of internal olefins to terminal olefins. This catalytic dehydrosilylation is one of the few examples of thermal catalytic functionalizations of unactivated alkylsilanes. The reaction involves transmetalation of an alkylsilane, -hydride elimination, release of the terminal olefin, and reoxidation of the palladium catalyst. A variety of linear internal olefins underwent the overall isomerization to terminal olefins in good yields and in good regioselectivities. Particularly noteworthy, isomerizations occurring over seven carbon units proceeded in yields that are comparable to those of isomerizations occurring over one carbon unit.