Synthesis of novel oxazaborolidines B-C6F5 and their effectiveness as asymmetric catalysts

Novel oxazaborolidines B-C6F5 were synthesized by modified protocol from C6F5B(OMe)2 (in place of usual C6F5B(OH)2) and the corresponding amino alcohols, aiming to know the π–π stacking and electron-withdrawing effects of C6F5 group in asymmetric reduction of ketones. Although the results were not simply explained by the expected effects, significant difference was observed in the enantioselectivity between the catalysts with B-C6H5 and B-C6F5.