Radical adamantyldenitration in polynitrobenzenes. Selectivity of homolytic aromatic ipso substitution
作者:Lorenzo Testaferri、Marcello Tiecco、Marco Tingoli
DOI:10.1039/p29790000469
日期:——
1-Adamantyl radicals react with 3,5-dinitro-1-X-benzenes (Ia–d), 2,4-dinitro-1-X-benzenes (IIa–e), and 2,4,6-trinitro-1-X-benzenes (IIIa–c) to effect selectively the displacement of the nitro group. This adamantyl-denitration represents a further example of the ease of radical substitution at an ipso position. The same substrates react with phenyl and methyl radicals, but the reaction takes a completely
1-金刚烷基与3,5-二硝基-1-X-苯(Ia–d),2,4-二硝基-1-X-苯(IIa–e)和2,4,6-三硝基-1反应-X-苯(IIIa–c)选择性地取代硝基。该金刚烷基-脱硝表示在ipso位置上容易进行自由基取代的另一个实例。相同的底物会与苯基和甲基基团反应,但反应过程完全不同。唯一获得的产物来自未取代核位置的进攻。这种剧烈变化的行为归因于金刚烷基和苯基或甲基自由基的不同极性,这决定了向芳族底物的自由基加成过渡态性质的变化。