Synthesis of 2-Acylvinyl Ethers by Reaction of Chromium (Fischer) Carbene Complexes and Stabilized Sulfur Ylides

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• 作者：Benito Alcaide ; Luis Casarrubios ; Gema Domí ; nguez ; and Miguel A. Sierra
• 刊名：Organometallics
• 出版年：1996
• 出版时间：October 15, 1996
• 年：1996
• 卷：15
• 期：21
• 页码：4612 - 4617
• 全文大小：206K
• 年卷期：v.15,no.21(October 15, 1996)
• ISSN：1520-6041

文摘

Irradiation ( > 360 nm) of equimolar amounts ofalkoxychromium(0) carbene complexes1 and stabilized sulfur ylides 2 renders2-acylvinyl ethers 3 in good to excellent yieldsasE/Z mixtures upon visible (sunlight preferred) oxidation toeliminate the metallic moiety.Formation of 2-acylvinyl ethers 3 is compatible withdifferent groups attached to the carbeneoxygen, including chiral fragments and unsaturated substituents.Variation of the substituent at the carbene carbon including alkyl, cycloalkyl, aromatic,and heteroaromaticsubstituents is also viable. The overall process is equivalent tothe totally site-selectiveenolization of a -keto ester or -diketone. 2-Acylvinylethers 3 are obtained with yieldsand selectivities ranking among the best of the synthetic approaches tothese compoundsreported previously. 2-Acylvinyl ethers 3 can beobtained also in the dark at roomtemperature, but reaction times are considerably longer.