C–N bond formation via Cu-catalyzed cross-coupling with boronic acids leading to methyl carbazole-3-carboxylate: synthesis of carbazole alkaloids

Abstract

Copper promoted N-arylation of methyl 4-amino-3-iodobenzoate with boronic acids followed by Pd-catalyzed intramolecular C–H arylation provides an efficient route to methyl carbazole-3-carboxylate derivatives. This methodology was implemented in the synthesis of naturally occurring carbazole alkaloids clausine C, clausine H, clausine L, clausenalene, glycozoline, glycozolidine, glycozolidal and sansoakamine.