A unified approach to benzo[c]phenanthridines via the cascade dual-annulation/formylation of 2-alkynyl/alkenylbenzonitriles†
Abstract
A base-mediated versatile cascade dual-annulation and formylation of 2-alkenyl/alkynylbenzonitriles with 2-methylbenzonitriles has been established for the construction of four different classes of amino and amido substituted benzo[c]phenanthridines and benzo[c]phenanthrolines. The synthesized molecules could be of utmost relevance in pharmaceuticals. The transformation uses the solvent DMF as the formyl source for synthesis of the amido-substituted scaffolds. This transition-metal-free unique strategy enables the formation of multiple C–C and C–N bonds in one pot at room temperature.