Synthesis of imidazole-fused pentacyclic pyrrolo[3,4-c]coumarins via base-promoted rearrangement of coumarin-substituted N-heterocyclic carbene precursors

Abstract

The stoichiometric reaction between coumarin-substituted N-heterocyclic carbene (NHC) precursors and Pd(OAc)2, in the presence of an external base, yielded imidazole-fused pentacyclic pyrrolo[3,4-c]coumarin derivatives.