Palladium-Catalyzed Desulfitative Cross-Coupling of Arylsulfonyl Hydrazides with Terminal Alkynes: A General Approach toward Functionalized Internal Alkynes.

A palladium-catalyzed Sonogashira-type coupling between arylsulfonyl hydrazides and terminal alkynes via Ar(C)-S bond cleavage is disclosed, which enables the general synthesis of functionalized internal alkynes, especially the Br-substituted ones, in good to excellent yields under acid- and base-free conditions.