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Synlett 1997; 1997(9): 1087-1089
DOI: 10.1055/s-1997-1543
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The Chemistry of Chlorosilyl Enolates 3.: Variation of the Silyl Group and the Effect on Rate and Enantiomeric Excess of Acetate Aldol Additions

Scott E. Denmark* , Stephen B.D. Winter
  • *Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, Illinois 61801, USA, Fax +1(217)333-3984; e-mail denmark@aries.scs.uiuc.edu
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Publikationsdatum:
31. Dezember 2000 (online)

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The rates of reaction of the silyl ketene acetals CH2=C(OMe)OSiCl2R (1a-d) with benzaldehyde and pivalaldehyde have been determined and follow the order R = H ~ Cl > Ph > Me. These reactions are promoted by catalytic amounts of a chiral phosphoramide; enantioselectivities of the products obtained show a high sensitivity towards variation of the silyl group. The reactions of the dialkyl substituted chlorosilyl enolates CH2=C(OMe)OsiClR2 (1e,f) with benzaldehyde are not promoted by HMPA.

aldol - catalytic - asymmetric - chiral Lewis base