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
S-Allyl Thiocarbamates from Allylic Alcohols by in situ [3,3]-Sigmatropic Rearrangement of a Thiocarbonyldiimidazole Adduct
作者:Jonathan Clayden、Gaëlle Mingat
DOI:10.1055/s-0032-1316746
日期:2012.9
97%) over two steps. Treatment of allylic alcohols with thiocarbonyldiimidazole generates an unstable O-allyl imidazolyl thione ester, which rearranges spontaneously and in high yield to the corresponding S-allyl imidazolyl thiol ester. Displacement of the imidazole by N-alkylanilines in the presence of a nucleophilic catalyst (HOBt or ECHIA) gives S-allyl N-aryl thiocarbamates in excellent yields (up