Synthesis of novel chiral bis(2-oxazolinyl)xanthene (xabox) ligands and their evaluation in catalytic asymmetric 1,3-dipolar cycloaddition reactions of nitrones with 3-crotonoyl-2-oxazolidinone

被引：27

作者：

Iwasa, S ^{[1
]}

Ishima, Y

Widagdo, HS

Aoki, K

Nishiyama, H

机构：

[1] Toyohashi Univ Technol, Sch Mat Sci, Toyohashi, Aichi 4418580, Japan

[2] Nagoya Univ, Dept Appl Chem, Grad Sch Engn, Nagoya, Aichi 4648603, Japan

来源：

TETRAHEDRON LETTERS | 2004年 / 45卷 / 10期

关键词：

1,3-dipolar cycloaddition; nitrone; molecular catalyst; xanthene backbone; nitrogen ligand;

D O I：

10.1016/j.tetlet.2004.01.043

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

Chiral 4,5-bis(2-oxazolinyl)-(2,7-di-tert-butyl-9.9-dimethyl)-9H-xanthenes (xabox) were synthesized and the chiral environments were evaluated in catalytic asymmetric 1,3-dipolar cycloaddition reactions of nitrones resulting in good to excellent enantioselectivities. 1.3-Dipolar cycloaddition reactions of nitrones with 3-crotonoyl-2-oxazolidinone in the presence of a bis(2-oxazolinyl)xanthene (4c: xabox-Bn) and Mn(II) or Mg(II) complex as a chiral Lewis acid catalyst proceeded smoothly to give the corresponding cycloadducts ranging from 96:4 to >99:1 of endorexo ratio and ranging front 91% to 98% ee for the endo adduct. (C) 2004 Elsevier Ltd. All rights reserved.

引用

页码：2121 / 2124

页数：4

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