Cascade Reaction by I2/Base-Promoted Synthesis of Chromeno-[3,4-c]pyrrol-4(2H)-ones from 2-Hydroxychalcones and β-Enamine Esters

摘要

An efficient methodology for the synthesis of a variety of chromeno[3,4-c]pyrrol-4(2H)-ones from 2-hydroxychalcones and N-substituted β-enamine esters via I2/base promoted Michael addition/cyclization/lactonization/aromatization sequence have been developed,affording the coumarin heterocyclic derivatives in moderate to excellent yields.This approach is a highly efficient and convenient way to get derivatives of chromeno[3,4-c]pyrrol-4(2H)-ones from readily accessible substrates under green reaction conditions.