Acid-Catalyzed Multicomponent Tandem Cyclizations: Access to Polyfunctional Dihydroindolizino[8,7-b]indoles.

An acid-catalyzed multicomponent tandem cyclization protocol has been developed for the synthesis of polyfunctional dihydroindolizino[8,7-b]indoles from simple and readily available arylglyoxal monohydrates, tryptamines, and trans-β-nitrostyrenes or malononitrile. This reaction represents a highly efficient and convenient methodology for the synthesis of diversely substituted heteropolycyclic scaffolds under mild, metal-free conditions. [ABSTRACT FROM AUTHOR]