Chemodivergent C-to-N atom swap from benzofurans to benzisoxazoles and benzoxazoles

Abstract

Facile derivatization of biologically active compounds without prefunctionalization expands the chemical space and accelerates the discovery of new molecules. Atom swap reactions have recently emerged as powerful molecular editing tools, yet such reactions remain rare. Herein, we describe a convenient, chemodivergent protocol to perform a net C-to-N atom swap in benzofurans, affording benzoxazoles or benzisoxazoles via a cascade of oxidative cleavage, oxime formation, and cyclization using commercially available reagents.