Thermal decomposition of tert-butyl ortho-(phenylsulfanyl)- and ortho-(phenylsulfonyl)phenyliminoxyperacetates: The reactivity of thio-substituted iminyl radicals
作者:Rino Leardini、Hamish McNab、Matteo Minozzi、Daniele Nanni
DOI:10.1039/b009843o
日期:——
Some ortho-(phenylsulfanyl)- and ortho-(phenylsulfonyl)-substituted phenyliminyl radicals have been generated by thermal decomposition of suitable tert-butyl iminoxyperacetates. The sulfanyl-substituted iminyls showed no tendency to give either 1,7- or 1,6-ring closure onto the S-phenyl ring. They gave instead 1,5-cyclisation onto the sulfur atom with release of a phenyl radical and formation of benzoisothiazoles. This seems to be the first example of SHi reaction of a nitrogen-centred radical at a sulfide moiety. On the other hand, the sulfonyl-substituted iminyl underwent 1,6-cyclisation to a small extent, furnishing a phenanthridine through an unprecedented 1,5-aryl radical migration from sulfur to nitrogen followed by loss of sulfur dioxide and ring closure of an aryl radical.
通过对合适的亚氨基过乙酸叔丁酯进行热分解,生成了一些正(苯硫基)和正(苯磺酰基)取代的苯基亚氨基自由基。硫酰基取代的亚氨基没有在 S-苯基环上产生 1,7 环或 1,6 环闭合的趋势。相反,它们在硫原子上产生 1,5 环化,释放出苯基自由基,形成苯并异噻唑。这似乎是以氮为中心的自由基在硫化物分子上发生 SHi 反应的第一个实例。另一方面,磺酰基取代的亚氨基发生了少量 1,6-环化反应,通过前所未有的 1,5-芳基自由基从硫转移到氮,然后二氧化硫脱落,芳基自由基闭环,生成了菲啶。