Free radical cyclisation of enamides leading to biologically important γ-lactams
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- 作者：Parsons ; Andrew F.
- 关键词：cyclisation ; lactams ; radicals and radical reactions ; cyclisation ; lactames ; radicaux et ré ; actions radicalaires
- 刊名：Comptes Rendus de l'Academie des Sciences Series IIC Chemistry
- 出版年：2001
- 出版时间：June, 2001
- 年：2001
- 卷：4
- 期：6
- 页码：391-400
- 全文大小：291 K
文摘
This review describes the free radical cyclisation of enamides using tributyltin hydride, manganese(III) acetate, copper(I) complexes or dichlorotris(triphenylphosphine)ruthenium(II). These cyclisations can proceed via either 4-exo or 5-endo pathways, to produce β- or γ-lactam products, respectively. In general, the reactions produce γ-lactams derived from an unusual (disfavoured) 5-endo-trig radical cyclisation. These results can be explained on the basis of a reversible cyclisation mechanism; the 4-exo cyclisation produces the kinetically favoured β-lactam while the 5-endo cyclisation produces the thermodynamically more stable γ-lactam.