Light Promoted Synthesis of Quinoxalines and Imidazo[1,2‐<i>a</i>]pyridines via Oxybromination from Alkynes and Alkenes

Abstract

Abstract Light promoted two‐step one‐pot syntheses of quinoxalines and imidazo[1,2‐a]pyridines from alkynes and alkenes, respectively under mild conditions are described. The conversions occur via the formation of α,α′‐dibromo ketones or α‐bromo ketones on irradiation with UV LED fluorescent black light (380–390 nm) in acetonitrile/water mixture. This protocol does not require sensitizer or catalyst or additives. This two‐step protocol is a new entry of synthetic methods available for quinoxaline and imidazopyridine derivatives and offers wide functional group tolerance.