过氧化环丙基甲酰在不同类型溶剂中的热分解

本文报道过氧化环丙基甲酰(1)在不同类型溶剂中的化学行为。首先,我们建立了五个热解主要产物:环丙基甲酸环丙酯(4)、环丙基甲酸(5)、双环丙烷(6)、环丙烷(7)及二氧化碳的色谱定量分析方法,然后在不同类型的溶剂中测定1热分解产物的分布。结果表明,在非极性碳氢溶剂中,以自由基型的单分子均裂过程为主;在极性溶剂中则可能伴有诱导分解。我们的结果还表明,产物4,6,7主要生成于笼外,与文献报道的不同。更有趣的发现是,在HMPA中,1的分解可能主要是通过它与溶剂间的电子转移来实现的.

The thermal decomposition of bis-(cyclopropylformyl) peroxide in various solvents.

Very recently, we discovered that when cyclopropyl radicals are added to vinylidene fluoride, the regioselectivity of the addition is probably affected by a genometry factor of the solvent molecules. On the other hand, literature reports on the chemical behavior of the precursor of the cyclopropyl radicals, bis (cyclopropylformyl) peroxide (1) in various solvents are not consistent with each other. Therefore we decided to investigate the chemical behavior of the peroxide 1 in various solvents in more detail. Firstly, a procedure to measure quantitatively the five major products, viz., cyclopropyl cyclopropanecarboxylate (4), cyclopropylcarboxylic acid (5), bicyclopropane (6), cyclopropane (7) and carbon dioxide, was worked out, then the variations of the yields of each product from the decomposition of 1 were determined in seven different solvents. Our results indicate that in non-polar hydrocarbon solvents the main reaction is the unimolecular decomposition of 1, and in polar solvents there is also an induced decomposition. the observation that most of products 4, 6 and 7 are formed outside of the cage disaccords with literature reports. More interestingly, we discovered that the decomposition of 1 in HMPA might proceed via an electron transfer machanism involving the solvent molecules as donors.