Regioselective Synthesis of Phenoxathiin Derivatives under Transition-Metal-Free Conditions

A simple and efficient method was developed for the synthesis of phenoxathiin derivatives. A range of 1,2-dihaloarenes or 1-halo-2-nitroarenes reacted with 2-sulfanylphenol to give the desired products in good-to-excellent yields. It is intriguing that 1-halo-2-nitroarenes containing electron-donating groups worked well as substrates in this reaction.