Copper-catalyzed aerobic cyclizations of tetrahydroisoquinolines with bromoketones and alkenes for the synthesis of 5,6-dihydropyrrolo[2,1-a]isoquinolines.

A new copper-catalyzed oxidative cyclization protocol was developed for the synthesis of 5,6-dihydropyrrolo[2,1-a]isoquinolines via a three-component reaction of tetrahydroisoquinolines with bromoketones and electron-deficient alkenes with air as a terminal oxidant. A variety of functional groups survived under the reaction conditions and the target products were obtained in good yields. This reaction features such advantages as eco-friendly reaction conditions, a simplified operation process and a broad substrate scope.