Photolysis of olefinic N-chloropyrrolidinones, N-chlorosuccinimides and N-chloro-oxazolidinones: Reactivity of cyclic carboxamidyl, imidyl and carbamyl radicals in intramolecular reactions
作者:Benoit Daoust、Jean Lessard
DOI:10.1016/s0040-4020(98)01158-2
日期:1999.3
carboxamidyl, imidyl and carbamyl radicals constrained to undergo intramolecular reactions uniquely via their planar or slightly twisted (30–35°) ΠN state (1,5-transfer of an allylic hydrogen, 5-exo or 6-exo cyclization to give bicyclo[2.2.1]azaheptane and bicyclo[3.2.1]azaoctane skeletons respectively), those intramolecular reactions being unaccessible to the planar ΣN state. Their photolysis gave products
制备N-氯-烯基吡咯烷酮,N-氯-烯基琥珀酰亚胺和N-氯-烯基恶唑烷酮作为烯属环羧酰胺基,亚胺基和氨基甲酸酯基团的前体,这些化合物仅通过它们的平面或轻微扭曲(30-35°)π分子内发生反应。N状态(烯丙基氢的1,5-转移,5- exo或6- exo环化分别产生双环[2.2.1]氮杂庚烷和双环[3.2.1]氮杂辛烷骨架),这些分子内反应是平面无法获得的Σ ñ状态。他们的光解作用产生的产物独特地是由这些氮自由基的分子间反应产生的(添加到外部烯烃中,从溶剂中提取氢,烯丙基氢提取)。用N-氯-链烯基吡咯烷酮和N-氯-链烯基恶唑烷酮,观察到通过5-外显环化反应生成双环[3.3.0]氮杂辛烷衍生物的分子内反应。在这两种情况下,无论是Π Ñ和Σ Ñ环状酰胺基自由基的状态允许5 -外环化轨道重叠。