Dramatic improvement of the enantiomeric excess in the asymmetric conjugate addition reaction using new experimental conditions

被引：267

作者：

Alexakis, A ^{[1
]}

Benhaim, C ^{[1
]}

Rosse, S ^{[1
]}

Humam, M ^{[1
]}

机构：

[1] Univ Geneva, Dept Organ Chem, CH-1211 Geneva 2, Switzerland

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 2002年 / 124卷 / 19期

关键词：

D O I：

10.1021/ja025598k

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The asymmetric conjugate addition of dialkylzincs is usually performed with Cu(OTf)2 in toluene. We show that by using a copper carboxylate in Et2O, THF, or EtOAc, we strongly improve the enantioselectivity with a given ligand. Ee values up to 99.1% could be reached with new ligands based on the induced atropisomerism of a simple biphenol unit. In addition, we show that the Lewis acid effect of Cu(OTf)2 is not a significant. Copyright © 2002 American Chemical Society.

引用

页码：5262 / 5263

页数：2

共 26 条

[1]

Alexakis A, 2000, EUR J ORG CHEM, V2000, P4011, DOI 10.1002/1099-0690(200012)2000:24<4011::AID-EJOC4011>3.0.CO

[2]

2-D

[3] Asymmetric conjugate addition to alkylidene malonates [J].

Alexakis, A ;

Benhaim, C .

TETRAHEDRON-ASYMMETRY, 2001, 12 (08) :1151-1157

[4]

Alexakis A, 2001, SYNLETT, P1375

[5]

Alexakis A, 1999, SYNLETT, P1811

[6] Acceleration of the conjugate addition of diethyl zinc to enones by either Cu(OTf)(2) or trivalent phosphorus ligands [J].

Alexakis, A ;

Vastra, J ;

Mangeney, P .

TETRAHEDRON LETTERS, 1997, 38 (44) :7745-7748

[7] CHIRAL PHOSPHORUS LIGANDS FOR THE ASYMMETRIC CONJUGATE ADDITION OF ORGANOCOPPER REAGENTS [J].

ALEXAKIS, A ;

FRUTOS, J ;

MANGENEY, P .

TETRAHEDRON-ASYMMETRY, 1993, 4 (12) :2427-2430

[8] Enantioselective copper-catalyzed conjugate addition of dialkyl zinc to nitro-olefins [J].

Alexakis, A ;

Benhaim, C .

ORGANIC LETTERS, 2000, 2 (17) :2579-2581

[9]

Börner C, 2001, EUR J ORG CHEM, V2001, P2435

[10]

Christoffers J, 2001, SYNLETT, P723

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