A Drastic Effect of TEMPO in Zinc‐Catalyzed Stannylation of Terminal Alkynes with Hydrostannanes via Dehydrogenation and Oxidative Dehydrogenation

Abstract

Abstract With a system consisting of a catalytic zinc Lewis acid, pyridine, and TEMPO in a nitrile medium, terminal alkynes coupled with HSnBu 3 , providing alkynylstannanes with structural diversity. The resulting alkynylstannane, without being isolated, could be directly used for Pd‐ and Cu‐catalyzed transformations to deliver internal alkynes and more intricate tin‐atom‐containing molecules. Mechanistic studies indicated that TEMPOSnBu 3 formed in situ from TEMPO and HSnBu 3 works to stannylate the terminal alkyne in collaboration with the zinc catalyst, and that both of dehydrogenation and oxidative dehydrogenation processes are uniquely involved in a single reaction. magnified image