Synthesis of pyrazolo[5,1-a]isoindoles via silver-mediated cascade cyclization of 1,5-enynes with diazo compounds

Abstract

Herein, we report a silver-mediated cascade cyclization of 1,5enynes with diazo compounds for the direct synthesis of pyrazolo[5,1-a]isoindoles from simple acyclic precursors. This onepot process forges two rings and three new bonds via a sequential [3+2] cycloaddition/elimination/intramolecular aza-addition. The protocol features mild conditions, broad substrate scope, and good functional group tolerance, and the products can be readily transformed into diverse valuable derivatives.