American Chemical Society
ja9b07293_si_006.pdf (36.99 MB)

Enantioselective Imine Reduction Catalyzed by Phosphenium Ions

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journal contribution
posted on 2019-08-27, 14:36 authored by Travis Lundrigan, Erin N. Welsh, Toren Hynes, Chieh-Hung Tien, Matt R. Adams, Kayelani R. Roy, Katherine N. Robertson, Alexander W. H. Speed
The first use of phosphenium cations in asymmetric catalysis is reported. A diazaphosphenium triflate, prepared in two or three steps on a multigram scale from commercially available materials, catalyzes the hydroboration or hydrosilylation of cyclic imines with enantiomeric ratios of up to 97:3. Catalyst loadings are as low as 0.2 mol %. Twenty-two aryl/heteroaryl pyrrolidines and piperidines were prepared using this method. Imines containing functional groups such as thiophenes or pyridyl rings that can challenge transition-metal catalysts were reduced employing these systems.