Asymmetric cyclopropanation catalyzed by C2-symmetric bi(oxazolines)

被引：51

作者：

Boulch, R

Scheurer, A

Mosset, P

Saalfrank, RW

机构：

[1] Ecole Natl Super Chim Rennes, Lab Synth & Activat Biomol, F-35700 Rennes, France

[2] CNRS, F-35700 Rennes, France

[3] Univ Erlangen Nurnberg, Inst Organ Chem, D-91054 Erlangen, Germany

来源：

TETRAHEDRON LETTERS | 2000年 / 41卷 / 07期

关键词：

asymmetric reactions; copper; copper compounds; cyclopropanation; alkenes;

D O I：

10.1016/S0040-4039(99)02220-0

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

C-2-symmetric bi(oxazolines) 3a-e were prepared in three steps based on a tartaric-derived vicinal diamine as common precursor. These chiral ligands were studied with respect to their directive influence on the enantioselective copper catalyzed cyclopropanation of 1,1 -diphenylethylene and styrene. The highest enantioselectivities (79% ee) were achieved with bi(oxazoline) 3e, bearing bulky adamantyl groups even using commercial CuOTf. The presence of desiccants such as molecular sieves or magnesium sulfate was found to be crucial for high yields and reproducibility. (C) 2000 Elsevier Science Ltd. All rights reserved.

引用

页码：1023 / 1026

页数：4

共 15 条

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