Preparation of highly enantiomerically pure linear secondary alcohols via asymmetric reduction of prochiral ketones with borane
作者:Jiaxi Xu、Xianbin Su、Qihan Zhang
DOI:10.1016/s0957-4166(03)00373-2
日期:2003.7
alcohols, via the asymmetricoxazaborolidine-catalyzedboranereduction of prochiral ketones is described. The phenomenon of the enantioselectivity of 1-(4-alkoxylphenyl) alcohols lower than that of 1-(4-alkylphenyl) alcohols was found and rationalized to the coordination of the oxygen atom in the alkoxy groups to the catalyst and borane. Based on the rationale, the enantioselectivity of 1-(4-alkoxylphenyl)
Effect of Temperature on the Enantioselectivity in the Oxazaborolidine-Catalyzed Asymmetric Reduction of Ketones. Noncatalytic Borane Reduction, a Nonneglectable Factor in the Reduction System
作者:Xu、Wei、Zhang
DOI:10.1021/jo035203v
日期:2003.12.1
The effect of temperature on the enantioselectivity of the oxazaborolidine-catalyzedasymmetricboranereduction of ketones has been investigated carefully using alkyl aryl ketones with a variety of functional groups and a B-methoxyoxazaborolidine derived from trimethyl borate and (S)-alpha,alpha-diphenylprolinol as a catalyst. The reductions were carried out over a range of temperatures in THF and