Journal of the American Chemical Society, Vol.136, No.8, 3020-3023, 2014
Stereodivergent alpha-Allylation of Linear Aldehydes with Dual Iridium and Amine Catalysis
We describe the fully stereodivergent, dual catalytic alpha-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.