One-pot concise syntheses of benzimidazo[2,1-a]isoquinolines by a microwave-accelerated tandem process

Abstract Direct, efficient syntheses of the benzimidazo[2,1- a ]isoquinoline ring system have been achieved with 2-bromoarylaldehydes, terminal alkynes, and 1,2-phenylenediamines by a microwave-accelerated tandem process in which a Sonogashira coupling, 5- endo cyclization, oxidative aromatization, and 6- endo cyclization can be performed in a single synthetic operation.