Phosphine-Promoted Synthesis of 9H-Pyrrolo[1,2-a]indole Derivatives via an γ-Umpolung Addition/Intramolecular Wittig Reaction

摘要

The synthesis of substituted 9H -pyrrolo[1,2-a ]indole products from 1H -indole-2-carbaldehydes and allenoates is described, using a phosphine-promoted Michael addition/intramolecular Wittig reaction. This halide- and base-free methodology provides an efficient access to different tricyclic nitrogen-containing heterocycles (18 examples, 32–88% isolated yields).