A derivative of D-xylose, 1,2-O-isopropylidene-α-D-xylofuranose (1), with Ti(OiPr)4 was used as a chiral catalyst in the asymmetric alkylation of benzaldehyde with diethylzinc (Et2Zn) for the high-yield production (90% conversion) and moderate enantioselectivity (45% ee (S)) of 1-phenyl-1-propanol. Optimum conditions (conversion and enantioselectivity) for the catalytic system formed by 1 and Ti(IV) were 10.0 mol % of 1 and 1 equivalent of Ti(IV) with respect to benzaldehyde in CH2Cl2 as a solvent, at room temperature. In the asymmetric alkylation of benzaldehyde with Et2Zn compound 1 in substoichiometric amount with Ti(OiPr)4 forms a chiral catalyst of the Ti(IV)-sugar type that ensures the good-yield conversion and the enantioselectivity of the reaction.
diethylzinc; xylose derivative; Ti(IV); titanium
