Unusual Deoxidative Coupling Reaction of β-Sulfinyl Esters with Benzylic Trimethylammonium Salts.

A KOH-promoted unusual deoxidative coupling reaction of β-sulfinyl esters with benzylic trimethylammonium salts to produce thioethers is discovered for the first time. If quaternary ammonium salts synthesized from enantiomerically enriched amines are adopted, highly enantiomerically enriched benzyl thioethers (>95-99% ee) with configurations opposite to those of the enantiomerically enriched amines are obtained.