Mechanism of the sulfurisation of phosphines and phosphites using 3-amino-1,2,4-dithiazole-5-thione (xanthane hydride)
作者:Jiří Hanusek、Mark A. Russell、Andrew P. Laws、Petr Jansa、John H. Atherton、Kevin Fettes、Michael I. Page
DOI:10.1039/b616298c
日期:——
report, the sulfurisation of phosphorus(III) derivatives by 3-amino-1,2,4-dithiazole-5-thione (xanthane hydride) does not yield carbon disulfide and cyanamide as the additional reaction products. The reaction of xanthane hydride with triphenyl phosphine or trimethyl phosphite yields triphenyl phosphine sulfide or trimethyl thiophosphate, respectively, and thiocarbamoyl isothiocyanate which has been trapped
与先前的报告相反,3-氨基-1,2,4-二噻唑-5-硫酮(黄原氢化物)对磷(III)衍生物的硫化不会产生作为额外反应产物的二硫化碳和氰胺。黄原酸氢化物与三苯基膦或亚磷酸三甲酯的反应分别产生三苯基膦硫化物或三甲基硫代磷酸酯,以及已被亲核试剂捕获的硫代氨基甲酰基异硫氰酸酯。该反应途径涉及磷在黄原氢化物的硫代羰基旁边的硫处最初的亲核进攻,然后分解形成产物的intermediate中间体。乙腈中取代的三苯膦和亚磷酸三苯酯硫化的哈米特rho值约为-1.0。活化的熵非常负(-114 +/- 15 J mol-1 K-1),对溶剂的依赖性很小,这与导致过渡态的双分子缔合步骤相一致。ΔS(不等于)和rho值的负值表明,硫化反应的限速步骤是形成具有早期过渡态且几乎没有共价键形成的the离子中间体。亲核攻击的位点也已经通过计算得到证实。ΔS(不等于)和rho值的负值表明,硫化反应的限速步骤是形成具有早期过渡态