Expedient Synthesis of N-Fused Indoles through an Intramolecular [3+2]-Cycloaddition Approach

Abstract

A variety of N-fused indolo pyrrolo-pyrroles and pyrrolo-pyrrolizidines were synthesized by intramolecular 1,3-dipolar cycloaddition reaction of azomethine ylide generated from N-alkenylindole carbaldehyde which were prepared by the N-alkylation of indole 2-aldehyde with Baylis-Hillman bromides.