ASYMMETRIC HOMOGENEOUS HYDROGENATION OF IMINES USING RHODIUM PHOSPHINE SYSTEMS

被引:42
作者
CULLEN, WR
FRYZUK, MD
JAMES, BR
KUTNEY, JP
KANG, GJ
HERB, G
THORBURN, IS
SPOGLIARICH, R
机构
[1] Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Y6
来源
JOURNAL OF MOLECULAR CATALYSIS | 1990年 / 62卷 / 03期
基金
加拿大自然科学与工程研究理事会;
关键词
13;
D O I
10.1016/0304-5102(90)85220-C
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
An efficient, reproducible system for the asymmetric homogeneous catalytic hydrogenation of imines is presented. By optimization of a number of parameters, it has been found that the combination of a chiral bidentate phosphine having a two-carbon backbone such as cycphos (cycphos = 1,2-bis(diphenylphosphino)-1-cyclohexylethane) with a rhodium(I) precursor in methanol-benzene or methanol-toluene at pressures between 1000 and 1500 psi hydrogenates the imine ArNC(CH2OMe)CH3 (Ar = 2,6-dimethylphenyl or 2-methyl-6-ethylphenyl) in quantitative yield (reactions times range between 40 and 70 h) and with good enantioselectivity. The enantioselectivities range from 40 to 69% e.e. depending on the temperature, lower temperatures (-25°C) favouring the higher e.e. Some discussion of the mechanism is presented. © 1990.
引用
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页码:243 / 253
页数:11
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