Reactions of aryl sulfides and phosphorus(V) esters of thiols with acidic hydrogen peroxide
作者:Clifford A. Bunton、Houshang J. Foroudian、Nicholas D. Gillitt、Anurag Kumar
DOI:10.1139/cjc-77-5-6-895
日期:——
Oxidations of sulfides and phosphorus(V) esters of thiols by H 2O2 are catalyzed by H2SO4 and HClO4. Sulfides are 4-ZC6H4SMe, 1a-1e, respectively, Z = MeO, Me, H, Cl, NO2; PhSCH2CH2Cl, 2 ,P h 2S, 3, and the esters are Ph(R)PO·SEt, 4a, 4b, R = Ph, EtO. Electron donation by Z moderately accelerates reaction, but the sulfides are much more reactive than the esters. Reactions are first order in H 2O2 and substrate
H 2O2 氧化硫醇的硫化物和磷 (V) 酯由 H2SO4 和 HClO4 催化。硫化物分别为4-ZC6H4SMe、1a-1e,Z=MeO、Me、H、Cl、NO2;PhSCH2CH2Cl, 2 ,P h 2S, 3,酯类是Ph(R)PO·SEt, 4a, 4b, R = Ph, EtO。Z 的给电子会适度加速反应,但硫化物比酯反应性强得多。反应在 H 2O2 和底物中是一级反应,而在 H2SO4 中的二级速率常数 k2 与过量酸度 X 相关。log k2 与 X 的关系图具有 0.61-0.85 范围内的斜率。对于给定浓度的 H2SO4 和 HClO4,速率常数是相似的,不同之处在于,当 H2SO4 的浓度大于 50wt.% 时,会形成过氧单硫酸,然后观察到的速率常数会增加。甲磺酸是一种不如无机酸有效的催化剂。