Regioselective C–H Thioarylation of Electron-Rich Arenes by Iron(III) Triflimide Catalysis

A mild and regioselective method for the preparation of unsymmetrical biaryl sulfides using iron(III) catalysis is described. Activation N-(arylthio)succinimides powerful Lewis acid triflimide allowed efficient thiolation a range arenes, including anisoles, phenols, acetanilides, N-heterocycles. The was applicable late-stage tyrosine tryptophan derivatives used as key step synthesis pharmaceutically relevant sulfur-containing compounds such antibiotic dapsone antidepressant vortioxetine. Kinetic studies revealed that while bearing electron-deficient arenes underwent thioarylation catalyzed entirely by triflimide, with electron-rich displayed an autocatalytic mechanism promoted basic product.