One-electron oxidation of closed-shell molecules. Part 3. Oxidative cleavage of 1,2,2,2-tetrakis-(p-methoxyphenyl)ethanone with dibenzoyl and bis-(3,5-dinitrobenzoyl) peroxides: mechanistic changeover of the peroxide function from radical to molecular oxidation
作者:Ken'ichi Takeuchi、Osamu Murai、Shin Matsui、Takeshi Inoue、Toshikazu Kitagawa、Kunio Okamoto
DOI:10.1039/p29830001301
日期:——
anispinacolone (An3*C·*CO·An; *C 90%13C) indicated that p-methoxybenzoyl radical is formed, presumably by way of the radical cation [anispinacolone]+˙ which is produced by a single-electron transfer (s.e.t.) mechanism. The formation of the p-methoxybenzoyl radical was also indicated by spin-trapping experiments. The decomposition rates of (2) at 50.0°C are unaltered on addition of (1) in nonpolar solvents
通过过氧化二苯甲酰(2)或过氧化双-(3,5-二硝基苯甲酰基)(3)裂解1,2,2,2-四-(对甲氧基苯基)乙酮(苯乙酮)(1),得到三(-p -甲氧基苯基)苯甲酸甲酯(或3,5-二硝基苯甲酸酯)和苯甲酸(或3,5-二硝基苯甲酸)对甲氧基苯甲酸酐为主要裂解产物。13 C Nmr CIDNP的研究使用了标记的茴香吡喃酮(An 3 * C·* CO·An; * C 90%13 C),表明形成了对甲氧基苯甲酰基,大概是通过自由基阳离子[anispinacolone] + ˙形成的。由单电子转移(设置)机制产生。p的形成自旋捕获实验也表明了-甲氧基苯甲酰基。在非极性溶剂(如二氯甲烷,氯仿,四氯化碳,1,2-二氯乙烷和苯)中加入(1)后,(2)在50.0℃下的分解速率不变。而(3)中的分解速率明显加快。通过添加3,4-二氯苯乙烯,可以将(1)对(2)的裂解抑制为6.7倍,而对(1)对(3)的裂解几乎