Construction of a Protoberberine Alkaloid Skeleton via the Palladium-Catalyzed α-Arylation–Amide Formation Cascade

Abstract

In this work, we report the strategy of one-pot synthesis of protoberberine alkaloid derivatives via palladiumcatalyzed cascade α-arylation and cyclization, which can afford the target molecules in moderate to excellent isolated yields using commercially available raw materials under solvent-free conditions. This protocol provides an efficient and convenient path to multisubstituted protoberberine derivatives. In addition, it can directly afford natural alkaloids.

Recent advances in palladium‐catalyzed α‐arylation reactions

“…Li et al put forward an efficient one‐pot synthesis of dihydroisoquino[3,2‐ a ]isoquinolines via a tandem process of α‐arylation–cyclization catalyzed by palladium (Scheme 50). 75 This solvent‐free method was highly yielding and employed substrates that are commercially available and exhibits high functional group compatibility. The reaction was found to be optimum when Pd(OAc) 2 was used as a catalyst and Xantphos as ligand along with the base K 3 PO 4 .…”