Preparation of 1-phenylcyclohexa-2,5-diene-1-carboxylates and their use in free-radical mediated syntheses
Preparation of 1-phenylcyclohexa-2,5-diene-1-carboxylates and their use in free-radical mediated syntheses
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1-苯基环己-2,5-二烯-1-羧酸酯的制备及其在自由基介导合成中的应用
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
J. Walton
中科院分区：
文献类型：
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作者：
Paul A. Baguley;L. Jackson;J. Walton
研究了1-苯基环己-2，5-二烯-1-羧酸及其衍生物的合成路线。含有适当不饱和侧链的酯生成相应的烯基，因此在无有机锡的反应中得到良好的5-外环闭合产物产率。没有观察到苯基自由基从中间体环己二烯基型自由基中挤出，并且这种替代性的β-断裂在任何条件下都不竞争。然而，在类似的分子间过程中，烯烃烷基化的产率很低。作为该研究的副产品，发现1-苯基环己-2，5-二烯-1-羧酸（6）是有机溶剂中羟甲酰基（甲酸酯）自由基的有用来源。
Synthetic routes to pure 1-phenylcyclohexa-2,5-diene-1-carboxylic acid and derived esters were developed. Esters containing appropriately unsaturated side chains generated the corresponding alkenyl radicals and hence gave good yields of 5-exo ring closure products in organotin-free reactions. Extrusion of phenyl radicals from the intermediate cyclohexadienyl type radicals was not observed, and this alternative β-scission did not compete under any conditions. Yields from alkylations of olefins in analogous intermolecular processes were, however, poor. As a spin-off from the research, it was found that 1-phenylcyclohexa-2,5-diene-1-carboxylic acid (6) was a useful source of hydroxyformyl (formate) radicals in organic solvents.