Regio- and chemo-selective cyclization of allenic-Ugi products for the synthesis of 3-pyrroline skeletons

Abstract

A highly efficient and stable novel class of allenic-Ugi products through a Crabbé homologation reaction is successfully demonstrated. Then, a regio- and chemo-selective cyclization of allenic-Ugi derivatives in a 5-exo-dig fashion to access 3-pyrroline skeletons is developed. Also, computational studies were performed and explained to provide insights into the reaction mechanism. This approach displays high bond-forming efficiency and atom economy with high yields.