Catalytic asymmetric trifluoromethylthiolation via enantioselective [2,3]-sigmatropic rearrangement of sulfonium ylides

The asymmetric Doyle–Kirmse reaction using chiral Rh(II)- or Cu(I)-catalysts provides SCF3-containing compounds in a highly efficient and enantioselective manner. The reaction proceeds through enantioselective formation of sulfonium ylide from a diazoester and allyl- or propargyl trifluoromethyl sulfide, followed by concerted [2,3]-sigmatropic rearrangement with the transfer of chirality from sulfur to carbon.