The Chemistry of Chlorosilyl Enolates 3.: Variation of the Silyl Group and the Effect on Rate and Enantiomeric Excess of Acetate Aldol Additions

All articles of this category The rates of reaction of the silyl ketene acetals CH 2 =C(OMe)OSiCl 2 R ( 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 CH 2 =C(OMe)OsiClR 2 ( 1e,f ) with benzaldehyde are not promoted by HMPA. aldol - catalytic - asymmetric - chiral Lewis base