Catalytic Methylene Insertion between Amines and Terminal Alkynes via C-N Bond Cleavage of N , N -Dimethylacetamide: A Unique Route to Propargylic Amines.

A copper-based system allows for the methylene insertion between an amine and a milder nucleophile, including a terminal alkyne counterpart, via C-N bond cleavage of N , N -dimethylacetamide. The method gives an expedient access to propargylic amines in good to excellent yields. A wide-ranging substrate scope and late-stage functionalization of complex molecules make the protocol practically valuable.