Golden opportunities in stereoselective catalysis:: Optimization of chirality transfer and catalyst efficiency in the gold-catalyzed cycloisomerization of α-hydroxyallenes to 2,5-dihydrofurans

被引：90

作者：

Deutsch, Carl ^{[1
]}

Gockel, Birgit ^{[1
]}

Hoffmann-Roeder, Anja ^{[1
]}

Krause, Norbert ^{[1
]}

机构：

[1] Univ Dortmund, D-44227 Dortmund, Germany

来源：

SYNLETT | 2007年 / 11期

关键词：

allenes; chirality transfer; cycloisomerization; gold catalysis; heterocycles;

D O I：

10.1055/s-2007-98256

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

Whereas the cycloisomerization of phenyl-substituted alpha-hydroxyallene I to 2,5-dihydrofuran 2 catalyzed by gold(I) or gold(III) chloride takes place with considerable epimerization, high levels of axis-to-center chirality transfer can be reached in the presence of additives (e.g. 2,2'-bipyridine), by using a moderately coordinating solvent (e.g. THF), or by lowering the reaction temperature. The increased stability and selectivity of the catalysts thus formed allows their application to the cycloisomerization of various functionalized alpha- and beta-hydroxyallenes, as well as a decrease of the catalyst loading to 0.1%.

引用

页码：1790 / 1794

页数：5

共 49 条

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