Ruthenium-catalyzed hydrocarbamoylative cyclization of 1,6-diynes with formamides

Abstract

The ruthenium-catalyzed hydrocarbamoylative cyclization of 1,6-diynes with formamides afforded exocyclic-diene-type α,β,γ,δ-unsaturated amides with 100% stereoselectivity. A plausible mechanism involving ruthenium hydride species is proposed to explain the experimental results. Some control experiments, performed using DMF-d7 and/or D2O, corroborate the proposed mechanism.