The catalytic asymmetric aldol reaction of silyl ketene acetals with aldehydes in the presence of a chiral borane complex. Nitroethane as a highly effective solvent for catalytic conditions

Article abstract of DOI:10.1016/S0040-4039(00)61236-4

Catalytic asymmetric aldol reactions of silyl ketene acetals with aldehydes in the presence of 20 mol % of the chiral borane reagent, prepared in situ from the p-nitrobenzenesulfonamide of (S)-valine and BH₃-THF complex, gave β-hydroxy carboxylic acid esters in good chemical yields along with excellent enantioselectivity under conditions that employ nitroethane as an effective solvent.