Enantioconvergent Synthesis of Diarylmethane Drugs via Privileged Benzhydrol Intermediates.

The benzhydryl motif is a privileged pharmacophore in antihistaminic and neuroactive drugs. We present a broadly applicable, enantioconvergent synthesis of benzhydrols via asymmetric migratory Tsuji-Wacker oxidation of stilbenes. This constitutionally stereodivergent protocol operates without preactivated or sterically biased substrates, affording chiral α,α-diaryl ketones in up to 91% ee, which convert to benzhydrols without erosion of stereochemistry. The method enables concise syntheses of (S)-cloperastine and isotopically labeled (S)-diphenhydramine-d5, establishing chiral benzhydrols as versatile intermediates for redox- and step-economic drug assembly.