effect of the waste product hydrogen peroxide. It generates radicals in the presence of acid and ketones, which accelerate the reaction by providing an additional pathway to the reactive hydroperoxide intermediate. This discovery could be applied to achieve other Brønsted acid catalyzed oxidative coupling reactions.
Substituent effects on the decomposition of bis(tert-butylperoxy)cycloalkanes
作者:Kazuo Matsuyama、Hiromi Kumura
DOI:10.1021/jo00059a029
日期:1993.3
Decompositions of bis(tert-butylperoxy)cycloalkanes have been carried out in cumene and n-alkanes at temperatures of 80-120-degrees-C and have been compared mainly with the decomposition of tert-alkyl tert-butyl peroxides in order to investigate substituent effects on the homolytic scission of one O-O bond in gem-diperoxides. The decomposition rates of bis(tert-butylperoxy)cycloalkanes are much faster than those of tert-alkyl tert-butyl peroxides; the decomposition rates of the cycloalkanes decrease in the following order: cyclopentane > 3,5,5-trimethylcyclohexane > cyclohexane > cyclooctane > cyclododecane. The effect of ring size on the decomposition and the isokinetic relationships between the activation parameters suggest that stabilization of the transition state by electron donation from the cycloalkyl substituents and repulsion between lone-pair electrons on different peroxy oxygen atoms in the ground state are important factors in the decomposition of gem-diperoxides.
Synthesis of Geminal Bisperoxides by Acid-Catalyzed Reaction of Acetals and Enol Ethers with <i>tert</i>-Butyl Hydroperoxide
A new efficient procedure was developed for the synthesis of geminal bisperoxides by reaction of ketals and enol ethers with tert-butylhydroperoxide catalyzed by protic or Lewis acids.