Copper-catalyzed direct synthesis of 3-methylene-2-arylisoindolin-1-ones with calcium carbide as a surrogate of gaseous acetylene

Abstract

A novel strategy for the synthesis of 3-methylene-2-arylisoindolin-1-ones through Sonogashira cross-coupling/nucleophilic addition reactions using calcium carbide as a surrogate of gaseous acetylene, 2-bromo-N-(2-bromophenyl)benzamide substrates as starting materials, and copper as a catalyst was described. The salient features of this protocol are the use of a readily available and easy-to-handle alkyne source, broad substrate scope, open-air conditions, aqueous systems, and simple operation procedures. Furthermore, this methodology can be scaled up to gram scale.