Enantioselective α-Arylation of Aldehydes via the Productive Merger of lodonium Salts and Organocatalysis

The enantioselective alpha-arylation of aldehydes has been accomplished using diaiyliodonium salts and a combination of copper and organic catalysts. These mild catalytic conditions provide a new strategy for the enantioselective construction and retention of enolizable alpha-formyl benzylic stereocenters, a valuable synthon for the production of medicinal agents. As one example, this new asymmetric protocol has been applied to the rapid synthesis of (S)-ketoprofen, a commercially successful oral and topical analgesic.