The remarkably high rate of the reaction of p-NO2C6H4CH2P(S)(NMe2)Cl with Et2NH, the presence of deuterium in the benzylic methylene group of the product formed with Et2ND, and the relative lack of discrimination between competing Me2NH and Et2NH, suggest an elimination–addition mechanism for substitution, with a three-coordinate PV methylenethioxophosphorane (thiophosphene) intermediate 6.
对-NO2C6H4CH2P(S)(NMe2)Cl 与 Et2NH 的反应速率极高,与 Et2ND 形成的产物的苄基亚甲基中存在
氘,以及在竞争的 Me2NH 和 Et2NH 之间相对缺乏区分,这些都表明了一种消除-加成的取代机理,中间体 6 为三配位 PV 亚甲基
硫氧
磷烷(
硫磷烷)。