ENANTIOSELECTIVE HYDROGENATION OF ALPHA-KETOESTERS WITH CINCHONA-MODIFIED PLATINUM CATALYSTS - EFFECT OF ACIDIC AND BASIC SOLVENTS AND ADDITIVES

被引：174

作者：

BLASER, HU ^{[1
]}

JALETT, HP ^{[1
]}

WIEHL, J ^{[1
]}

机构：

[1] WC HERAEUS GMBH HANAU,PROD BEREICH CHEM,W-6450 HANAU,GERMANY

来源：

JOURNAL OF MOLECULAR CATALYSIS | 1991年 / 68卷 / 02期

关键词：

D O I：

10.1016/0304-5102(91)80076-F

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：

The effect of several organic acids and bases used as solvents and additives for the enantioselective hydrogenation of alpha-ketoesters with cinchona-modified platinum catalysts is described. Carboxylic acids have a positive influence on the enantioselectivity of the reaction, both as solvents and as additives. The best results are observed in acetic acid where the optical yields increase between 8 and 12% compared to toluene or ethanol as solvents. In addition, extremely low modifier concentrations are necessary. For the hydrogenation of ethyl pyruvate, using a special wide pore Pt/Al2O3 catalyst and 10,11-dihydro-O-methylcinchonidine as modifier, we obtained 95% enantioselectivity, the highest value ever reported for any chiral heterogeneous catalyst. Bases are not suitable as solvents but in some cases they have a beneficial effect as additives at low concentration.

引用

页码：215 / 222

页数：8

共 12 条

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