Radical promoted cyclisations of trichloroacetamides with silyl enol ethers and enol acetates: the role of the hydride reagent [tris(trimethylsilyl)silane vs. tributylstannane]
作者:Josefina Quirante、Carmen Escolano、Faïza Diaba、Josep Bonjoch
DOI:10.1039/a900952c
日期:——
Reactions between 1-(carbamoyl)dichloromethyl radicals and electron-rich alkenes acting as radical acceptors are reported for the first time. The intramolecular reaction of trichloroacetamides with silyl enol ethers gives ketones using (TMS)3SiH as the mediator, and alcohols when using Bu3SnH. The reaction with enol acetates gives acetates using either of the above hydride reagents. These radical processes have been applied to the synthesis of 2-azabicyclo[3.3.1]nonanes.
首次报道了 1-(氨基甲酰基)二氯甲基自由基与作为自由基受体的富电子烯烃之间的反应。以 (TMS)3SiH 为媒介,三氯乙酰胺与硅基烯醚发生分子内反应,生成酮;以 Bu3SnH 为媒介,生成醇。使用上述任一种氢化物试剂与烯醇乙酸酯反应可生成乙酸酯。这些自由基过程已被用于合成 2-氮杂双环[3.3.1]壬烷。