α-Thianthrenium Carbonyl Species: The Equivalent of an a-Carbonyl Carbocation

摘要

Here we report an a-thianthrenium carbonyl species, as the equivalent of an a-carbonyl carbocation, which is generated by the radical conjugate addition of a trifluoromethyl thianthrenium salt to Michael acceptors. The reactivity allows for the synthesis of C-tetrasub-stituted a-and |3-amino acid analogues via a Ritter reaction by addition of acetonitrile. Addition of hydroxide, methoxide, and even fluoride can afford a-heteroatom substituted a-phenylpropanoates.