Palladium-Catalyzed Dual Annulation: A Method for the Synthesis of Norneocryptolepine.

A novel procedure for the Pd-catalyzed dual annulation reaction to synthesize the norneocryptolepine derivatives involving the concerted construction of two central heterocycles is reported. The further methylation of the norneocryptolepine to afford its alkaloid analog neocryptolepine implies that synthesis of various neocryptolepine derivatives is feasible. The oxidative addition of Pd(0) is indicated as the key step to activate the intramolecular addition of nitrile according to the mechanism study.