Kinetic diastereomer differentiation in Au(III)- and Bi(III)-catalyzed benzylic arylation: concise and stereocontrolled synthesis of 2-amino-1,1-diarylalkanes.

Benzylic alcohols carrying an adjacent α-nitro or α-azido group on the alkane chain are converted into syn-1,1-diaryl-2-nitro- and 2-azidoalkanes with electron-rich arenes in stereoselective reactions catalyzed by Brønsted and Lewis acids. Gold(III) chloride and bismuth(III) triflate were found to be especially efficient as catalysts, showing kinetically controlled differentiation in the reactivity of diastereomeric α-substituted benzyl alcohols. Applications to therapeutically relevant syn- and anti- 2-amino-1,1-diarylalkanes are projected.