Calciate-mediated intermolecular hydroamination of diphenylbutadiyne with secondary anilines

Calciate-mediated intermolecular hydroamination of diphenylbutadiyne with N-phenyl and N-isopropyl-substituted anilines yields E- and Z-isomers of the corresponding 1-anilino-1,4-diphenylbut-1-ene-3-yne. In the case of HNPh2 solely heterobimetallic K2Ca(NPh2)(4) is able to effectively catalyze this hydroamination reaction in tetrahydrofuran at elevated temperatures.