Photocatalyst-free regioselective sulfonamidation of N-(2-hydroxyaryl)amides in visible-light

Abstract

In this work, we report a regioselective sulfonamidation of N-(2-hydroxyaryl)amides with iminoiodinanes and iodine in visible light at room temperature. The method does not require a strong oxidant, metal or photocatalyst and enables direct functionalization of a C–H bond to a C–N bond. Mechanistic investigations suggest in situ generation of an N-centered radical from N,N-diiodo-sulfonamide by homolytic N–I bond cleavage followed by its site-specific addition to N-(2-hydroxyaryl)amides to furnish para-sulfonamide derivatives.