1,3-Halogen migration as an entry to aryl coppers from an unintuitive starting material

Abstract

A copper(I) catalyzed 1,3-halogen migration/borylation migrates a bromine from an sp² carbon to a benzylic carbon with concomitant borylation of the aryl–bromine bond. This transformation proceeds via an aryl copper intermediate which can be accessed independently and then trapped with electrophiles. As such, copper-catalyzed 1,3-halogen migration provides unique and mild access to an aryl copper species that allows for rapid aromatic functionalization from an unconventional starting material.