CATALYTIC ACTIVITY OF CHIRAL BETA-HYDROXYSULFOXIDES IN THE ENANTIOSELECTIVE ADDITION OF DIETHYLZINC TO BENZALDEHYDE

The first examples of the use of readily available beta-hydroxysulfoxides 1-8 as chiral catalysts in the enantioselective addition of diethylzinc to benzaldehyde are reported. The increase of the steric hindrance around the chiral ligand OH group improves the e.e. of the obtained 1-phenylpropanol, which is higher with tertiary alcohols (25-45%) than with secondary ones (<23%). The addition of MeAl3 also affords better e.e. (55%).