Synthesis of β-enamino acid and heteroaryl acetic acid derivatives by Pd-catalyzed carbonylation of α-chloroimines and 2-chloromethyl aza-heterocycles

β-Enamino esters or amides can be synthesized in a single step by a carbonylative coupling of α-chloroimines with alcohols or amines under Pd-catalysis. The methodology has been also applied to the preparation of heteroaryl acetic acid derivatives starting from chloromethyl heteroaromatic rings containing a C-N double bond. The in situ generation of a β-imino acylpalladium species has been proposed as a key step for the process.