Solvent-dependent ambident nucleophilicity of phenoxide ion towards nitroporphyrins: synthesis of 2-hydroxyaryl- and 2-aryloxy-5,10,15,20-tetraphenylporphyrins by displacement of a nitro group
作者:Maxwell J. Crossley、Lionel G. King、Janelle L. Simpson
DOI:10.1039/a701673e
日期:——
the major product and none of the meta isomer is detected. The scope of the reaction has been extended by the use of the substituted phenols which are blocked from reaction para to the hydroxy (p-cresol and 2,4-dimethylphenol) or blocked from reaction in the ortho-positions (2,6-dimethylphenol). In this way the copper(II) 2-(2-hydroxy-5-methylphenyl)porphyrin 14 (86%), 2-(2-hydroxy-5-methylphenyl)porphyrin
已研究了苯氧化物离子与铜(II),镍(II)和游离碱2-硝基-5,10,15,20-四苯基卟啉(1-3)的反应,作为引入内向定向的方法预先存在的卟啉系统外围的功能。已经发现,酚盐离子对硝基卟啉体系显示出高度选择性的溶剂依赖性环境亲核性。卟啉1-3与苯酚离子在回流的苯酚中反应,得到相应的2-(邻羟基苯基)-和2-(对羟基苯基)-5,10,15,20-四苯基卟啉,收率很高。在每种情况下,邻位异构体都是主要产物,而没有任何间位异构体检测到异构体。通过使用取代的酚来扩大反应范围,所述取代的酚在羟基的对位被阻止反应(对甲酚和2,4-二甲基苯酚)或在邻位(2,6-二甲基苯酚)被阻止反应。)。这样,铜(II)2-(2-羟基-5-甲基苯基)卟啉14(86%),2-(2-羟基-5-甲基苯基)卟啉15(65%),铜(II)2-(2-羟基-3,5-二甲基苯基)卟啉16(77%),2-(2-羟基-3,5-二甲基苯