Metal-Free Selective para-Tosyloxylation of N-Arylbenzamides using [Hydroxy(tosyloxy)iodo]benzene

Abstract: An efficient approach for the tosyloxyl group transfer in several N-arylbenzamides has been achieved using HTIB (Koser’s reagent) under mild reaction conditions. Its simplicity, efficiency, and reduced reliance on hazardous reagents make it an attractive choice for chemists seeking sustainable alternatives. The proposed methodology offered single-step para-selective tosyloxylation, ensuring the prevention of the synthesis of mixtures of ortho and meta-isomers. The corresponding products were obtained with moderate to excellent efficiency. The current approach eliminated the need for harsh, acidic, and toxic metals, ensuring safer handling and minimizing environmental impact. A plausible mechanism for tosyloxylation of N-arylbenzamides involving iodonium ylide has been proposed.