Intramolecular cyanoamidation of unsaturated cyanoformamides catalyzed by palladium: an efficient synthesis of multi-functionalized lactams

The Pd(0)-catalyzed intramolecular cyanoamidation of several unsaturated cyanoformamides with alkenyl, allenyl, and alkynyl groups was investigated. In the cases of alkynyl and 1,1-disubstituted alkenyl cyanoformamides, the Pd(0)-catalyzed C–CN activation and subsequent insertion reaction proceeded smoothly and gave the corresponding lactams bearing a cyano group at the β-position in good yields. The mechanism of the reaction was also discussed.