Metal‐Free C−H Functionalization via Diaryliodonium Salts with a Chemically Robust Dummy Ligand

Abstract

A two-step strategy for the transition-metalfree CÀ H functionalization of arenes using unsymmetrical iodonium salts as versatile synthetic linchpins is presented. The key to the success of this strategy is the identification of the 3,5-dimethyl-4-isoxazolyl (DMIX) group as a superior dummy ligand, which enables not only site-selective CÀ H functionalization to afford unsymmetrical iodonium salts, but also highly selective aryl transfer during the subsequent metal-free coupling reaction. Both electron-rich and moderately electrondeficient arenes can be converted into the iodonium salts through CÀ H functionalization, allowing for diverse structural elaboration by metal-free CÀ N, CÀ C, CÀ S, and CÀ O coupling.