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研究了在β-环糊精存在下,苯乙酮衍生物中取代基团对不对称还原反应的影响.结果表明,当苯乙酮上连有取代基团且在低温下进行不对称还原反应时,对映体选择性得到提高,产物醇的绝对构型与取代基团的位置有关,苯乙酮及其间位、对位衍生物还原产物绝对构型为S型,邻位衍生物所得产物为R型.苯乙酮衍生物的对映体选择性是取代基团的大小、氢键作用、空间位阻等因素协同作用的结果.此外,根据取代基团的性质以及取代位置推测了底物在β-环糊精空腔内的可能定位.
The effect of the substituent groups on the asymmetric reduction of acetophenone derivatives in the presence of β-cyclodextrin was studied.The results showed that when the acetophenone was substituted with substituents and the asymmetric reduction reaction was carried out at low temperature , The enantioselectivity was improved. The absolute configuration of the alcohol was related to the position of the substituted groups. The absolute configuration of acetophenone and its meta- and para-derivatives was S-type. The ortho-derivative Is R. The enantioselectivity of acetophenone derivatives is the result of the synergetic effect of substituent groups size, hydrogen bonding, steric hindrance, etc. In addition, based on the nature of substitution groups and substitution position, Potential localization of β-cyclodextrin in the cavity.