Rh-Catalyzed Conversion of 3-Diazoindolin-2-imines to 5H-Pyrazino[2,3-b]indoles with Photoluminescent Properties.

A rhodium-catalyzed reaction between 3-diazoindolin-2-imines and 2H-azirines, followed by treatment with a base, furnishes 5H-pyrazino[2,3-b]indoles in excellent yields. A number of functional groups tolerate the reaction conditions, and the resulting 5H-pyrazino[2,3-b]indoles present strong photoluminecence in solutions, powders, and films.