Copper‐Catalyzed Hydroamination of Alkynes with Aliphatic Amines: Regioselective Access to (1E,3E)‐1,4‐Disubstituted‐1,3‐dienes.

Copper-catalyzed hydroamination of aromatic or heteroaromatic alkynes with cyclic secondary aliphatic amines undergoes generation of an enamine-type intermediate. The latter is transformed in situ via a coupling reaction with a second molecule of alkyne to afford regioselectively (1E,3E)-1,4-disubstituted-1,3-dienes with the formation of C–N, C–C, and C–H bonds.