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Please login or sign up for a free trial to access the full content. Enantioselective Reduction

DOI: 10.1055/sos-SD-202-00017

Zaidlewicz, M.; Pakulski, M. M.Science of Synthesis: Stereoselective Synthesis, (2011295.

Early organocatalytic asymmetric hydrosilylations of prochiral ketones, catalyzed by chiral Lewis bases, proceeded with low to moderate selectivity.[‌202‌‌205‌] A more recently developed chiral 5-phenyloxazole derivative, N-formyl pipecolinic acid amide, and N-formyl-α-(2,4,6-triethylphenyl)-(S)-proline (59) are all more selective.[‌171‌,‌206‌,‌207‌] The catalyst 59 is highly selective in the reduction of alkyl aryl ketones with trichlorosilane, producing the corresponding alcohols in up to 99.7% ee. Thus, acetophenone, 1-phenylpropan-1-one, and 1-phenylbutan-1-one, as well as ring-substituted acetophenones afford products of 9397% ee (Scheme 43).

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