In this study, we report a highly selective coupling reaction between triarylbismuthines and isocyanides using palladium diacetate as the catalyst, affording α-diimines, with the formation of three C-C bonds. Among several aryl sources (Ar-YLn: Y = B, Sn, Pb, Sb, Bi, I), only triarylbismuthines successfully undergo coupling with isocyanides to selectively afford α-diimines. The coupling reaction exhibits the advantages of high atom economy and convenient operation, with no need for any additive.