Bifunctional acidic ionic liquid-catalyzed decarboxylative cascade synthesis of quinoxalines in water under ambient conditions

Abstract

An acid-functionalized ionic liquid (IL)-catalyzed cascade decarboxylative cyclization of 2-arylanilines with α-oxocarboxylic acids was developed. This approach offered a sustainable and practical pathway to afford a library of quinoxalines in water under ambient conditions. This protocol tolerated various kinds of functional groups and could be easily scaled-up. The developed method featured a recyclable catalytic system, environmentally friendly reaction conditions, simple operation, and a practical workup procedure, which represented the potential to streamline quinoxaline synthesis in industry. A possible mechanism involving a dual activation strategy to promote both decarboxylation and cyclization processes was proposed.