Tertiary thiols from allylic thiocarbamates by tandem enantioselective [3,3]-sigmatropic rearrangement and stereospecific arylation

The synthesis of tertiary thiols in enantiomerically enriched form is accomplished by lithiation of enantiomerically enriched N-aryl allylic thiocarbamates. Formation of an allyllithium derivative promotes intramolecular N to C aryl migration to the position α to sulfur, generally with good stereospecificity. The substrates may themselves be obtained by Pd-catalyzed enantioselective [3,3]-sigmatropic rearrangement of N-aryl O-allyl thiocarbamates. Solvolysis of the product thiocarbamates yields tertiary thiols, which may be converted to sulfide derivatives. © 2014 American Chemical Society.