Base-promoted selective C2–N1 ring-expansion reaction of indolones toward substituted quinolines

Abstract

A base-promoted selective C2–N1 ring-expansion reaction of indolones toward substituted quinolines under mild conditions has been developed. This is the first example of a transition-metal free ring-expansion reaction of indolones via the selective insertion of alkynoates into the C2–N1 bond. The process achieved the cleavage of one C–N bond and three C–C bonds, and the formation of one C–N and three C–C bonds in one step.