Regioselective Synthesis of Pyrroles from Alkyne‐Isocyanide Click Reactions: An Angle Strain‐Induced Bond Migration Approach

Abstract

AbstractThe direct regioselective synthesis of highly functionalized pyrroles with two different electron‐withdrawing groups has been developed using an angle strain‐induced 1,2‐shift of an electron‐withdrawing group in 2H‐pyrroles. The preferential migration aptitude of an electron‐withdrawing group over alkyl and aryl groups is believed to be the result of the orbital overlap between the internal alkene and the electron‐withdrawing group. The newly developed regioselective synthesis of pyrroles features a wide substrate scope, simple reaction set‐up, and high yields (60–82%), capturing the essence of alkyne‐isocyanide “click” reactions.magnified image