溶剂控制的对甲苯磺酰肼选择性偶联反应

通过对反应条件的优化,发现对甲苯磺酰肼涉及的偶联反应具有明显的溶剂效应.当对甲苯磺酰肼在溶剂N,N-二甲基甲酰胺中加热时,可以通过自身还原偶联得到对甲苯二硫醚;当溶剂为乙酸乙酯时,可以通过自身偶联得到S-对甲苯基硫代对甲苯基砜.当用环己烷作溶剂时,通过加入催化剂醋酸铜以及氧化剂二叔丁基过氧化物可以有效地减少自身偶联的产物,从而选择性地得到对甲苯磺酰肼与环己烷自由基偶联产物对甲苯环己基砜.该反应提供了一种高效而绿色的含硫化合物的合成新方法.

Solvent-Controlled Selective Coupling Reaction of 4-Methylbenzenesulfonohydrazide

An obvious solvent effect of the coupling reaction involving 4-methylbenzenesulfonohydrazide was observed by optimization of the reaction conditions.1,2-Di-p-tolyldisulfane was efficiently obtained via reducting self-coupilng when 4-methylbenzenesulfonohydrazide was heated in solvent of N,N-dimethylformamide;S-(ptolyl)4-methylbenzenesulfonothioate was selectively generated whereas 4-methylbenzenesulfonohydrazide was heated in solvent of ethyl acetate.A cross-coupling product of 1-(cyclohexylsulfonyl)-4-methylbenzene was obtained via a free-radical process under the catalysis of cupric acetate monohydrate/di-t-butyl peroxide system when the solvent of cyclohexane was added to 4-methylbenzenesulfonohydrazide.The reaction described here enables a novel,efficient and green synthetic method for S-containing compound construction.