Crich David, Hutton Thomas K, Ranganathan Krishnakumar
Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607-7061, USA.
J Org Chem. 2005 Sep 16;70(19):7672-8. doi: 10.1021/jo050990c.
[reaction: see text] A series of 2-alkylsulfonyl-2'-biphenyl radicals, in which the alkyl group is primary, secondary, or tertiary, were generated and the products of their reactions investigated. Dibenzothiophene S,S-dioxide was not identified among the products, which arose mainly from intramolecular hydrogen abstraction from the alkyl group or addition to the solvent, benzene. On this basis, it is concluded that homolytic substitution at sulfonyl sulfur, if possible at all, is too slow to take precedence over a number of competing decomposition pathways. Previous literature results suggesting the possibility of intramolecular homolytic substitution at sulfonyl sulfur may be explained by alternative processes.
[反应:见正文] 生成了一系列2-烷基磺酰基-2'-联苯自由基,其中烷基为伯、仲或叔烷基,并对其反应产物进行了研究。在主要由烷基的分子内氢提取或与溶剂苯加成产生的产物中未鉴定出二苯并噻吩S,S-二氧化物。在此基础上,可以得出结论,磺酰基硫上的均裂取代(如果可能的话)太慢,无法优先于许多竞争性分解途径。先前文献中表明磺酰基硫上可能发生分子内均裂取代的结果可能由其他过程来解释。