A Desulphurization Strategy for Sonogashira Couplings by Visible Light/copper Catalysis

The development of new copper-based catalysts in photoredox transformations has become a rapidly growing area of research and has been actively explored in the past several years. Herein, we have developed a new copper-based catalyst, [(binap)(tpy)Cu]Cl, and applied it in the visible-light promoted Sonogashira coupling reactions. This mild protocol results in various substituted alkynes from simple sulfonium salts which can be easily prepared from commercially available and inexpensive thiols, alcohols, and alkyl halides. This study will broaden the still limited strategies of copper photocatalysts in organic transformations.