Asymmetric Weitz-Scheffer epoxidation of conformationally flexible and fixed enones with sterically demanding hydroperoxides mediated by optically active phase-transfer catalysts

被引：34

作者：

Adam, W ^{[1
]}

Rao, PB ^{[1
]}

Degen, HG ^{[1
]}

Saha-Möller, CR ^{[1
]}

机构：

[1] Univ Wurzburg, Inst Organ Chem, D-97074 Wurzburg, Germany

来源：

TETRAHEDRON-ASYMMETRY | 2001年 / 12卷 / 01期

关键词：

D O I：

10.1016/S0957-4166(00)00497-3

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

The asymmetric Weitz-Scheffer epoxidation of alpha,beta -enones 1a-d with hydroperoxides 2 and mediated by cinchonine-and cinchonidine-derived phase-transfer catalysts (PTCs)3 affords the optically active epoxides 4 with moderate to very good e.e.s and in near quantitative yields. For the conformationally flexible enone 1b, the enantioselectivity decreases with more sterically demanding tertiary hydroperoxides, while an opposite trend is observed for the rigid s-cis-enone I. With the bulky cumyl hydroperoxide 2c and the PTC 3c, the enone 1 was converted to the epoxide 4c with the highest enantioselectivity (95% e.e.) so far observed for PTC-catalyzed epoxidations using hydroperoxides as oxygen sources. (C) 2001 Elsevier Science Ltd. All rights reserved.

引用

页码：121 / 125

页数：5

共 13 条

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