A Bithiophene-Promoted ppm Levels of Palladium-Catalyzed Regioselective Hydrosilylation of Terminal Allenes

A bithiophene-alkyne-based compound was synthesized and first utilized as a ligand for the selective hydrosilylation of allenes with primary and secondary phenylsilanes. It shows high selectivity towards the production of branched allylsilanes with a wide range of allenes. It is worth mentioning that the catalytic loading of the palladium can be reduced to 500 ppm. This work opens a new front of using bidentate thiophene ligand as a reaction promoter in transition-metal-catalyzed organic reaction.