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

[1]

Blaser H. U., 1988, HETEROGENEOUS CATALY, P153

[2]

BLASER HU, 1991, STUD SURF SCI CATAL, V59, P73

[3]

BLASER HU, 1990, APR ACS S STRUCT ACT

[4] A HETEROGENEOUS LIGAND-ACCELERATED REACTION - ENANTIOSELECTIVE HYDROGENATION OF ETHYL PYRUVATE CATALYZED BY CINCHONA-MODIFIED PT/AL2O3 CATALYSTS [J].

GARLAND, M ;

BLASER, HU .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1990, 112 (19) :7048-7050

[5]

NOYORI R, 1989, MOD SYN MET, V5, P115

[6]

Onto Y., 1979, J CHEM SOC JPN, P1118

[7]

Onto Y., 1980, J CHEM SOC JPN, P670

[8] ASYMMETRIC HYDROGENATION OF METHYL BENZOYLFORMATE USING PLATINUM-CARBON CATALYSTS MODIFIED WITH CINCHONIDINE [J].

ORITO, Y ;

IMAI, S ;

NIWA, S ;

NGUYENGIAHUNG .

JOURNAL OF SYNTHETIC ORGANIC CHEMISTRY JAPAN, 1979, 37 (02) :173-174

[9]

Orito Y., 1982, J CHEM SOC JPN, V137

[10]

TAI A, 1986, TAILORED METAL CATAL, P275

← 1 2 →