Stereodivergent α-allylation of linear aldehydes with dual iridium and amine catalysis

J Am Chem Soc. 2014 Feb 26;136(8):3020-3. doi: 10.1021/ja5003247. Epub 2014 Feb 13.

Abstract

We describe the fully stereodivergent, dual catalytic α-allylation of linear aldehydes. The reaction proceeds via direct iridium-catalyzed substitution of racemic allylic alcohols with enamines generated in situ. The use of an Ir(P,olefin) complex and a diarylsilyl prolinol ether as catalysts in the presence of dimethylhydrogen phosphate as the promoter proved to be crucial for achieving high enantio- and diastereoselectivity (>99% ee, up to >20:1 dr). The utility of the method is demonstrated in a concise enantioselective synthesis of the antidepressant (-)-paroxetine.