Chiral aminoalcohol catalysts and methods for their preparation are provided. The first catalyst is prepared via selective hydrogenation of one of two benzene rings in a precursor. The aminoalcohol promotes the asymmetric addition of organozinc reagents to aldehydes to afford optically active alcohols or their esters. The second catalyst is prepared by selective dialkylation of 3-exo-aminoisoborneol with a 2-haloethyl ether. The aminoalcohol promotes the addition of organozinc reagents to aliphatic aldehydes containing a &bgr;-branch with greatly enhanced enantioselectivity relative to DAIB.
提供手性
氨醇催化剂及其制备方法。第一种催化剂是通过选择性氢化前体中的两个苯环之一制备的。
氨醇促进
有机锌试剂对醛的不对称加成,生成光学活性醇或其酯。第二种催化剂是通过选择性对3-外
氨基异螺烷基与2-卤
乙基醚进行二烷基化制备的。
氨醇促进对含有β-支链的脂肪族醛的
有机锌试剂加成,相对于
DAIB具有大大增强的对映选择性。