Rhenium-Catalyzed anti-Markovnikov Addition Reaction of Methanetricarboxylates to Unactivated Terminal Acetylenes

A novel anti-Markovnikov addition reaction of methanetricarboxylates with terminal acetylenes under neutral conditions was achieved using a rhenium complex. This transformation represents a rare example of intermolecular anti-Markovnikov addition of carbon nucleophiles to unactivated terminal acetylenes. 1,3-Diesters having bulky substituents at the active methylene carbon are also applicable as substrates to provide anti-Markovnikov adducts as single regio- and stereoisomers. Preliminary mechanistic studies imply that the rhenium vinylidene species is the key intermediate in the current catalytic cycle.