Novel regio- and stereo-selectivity: synthesis of dihydropyrrolo[1,2-f]phenanthridines via isocyanide-based multicomponent reaction

The novel one-pot three-component reactions of the zwitterions generated in situ from three isocyanides and 2-arylidenemalononitriles with phenanthridine via 1,3-dipolar cycloaddition are described. The reactions afforded the corresponding dihydropyrrolo[1,2-f]phenanthridine derivatives in good yields without using any catalyst and activation. The stereochemistry of the final products was confirmed by single-crystal X-ray diffraction analysis.