Influence of ortho methyl and isopropyl substituents on the reactivity of N-t-butyl P-arylphosphonamidic chlorides with isopropylamine and t-butylamine: steric acceleration of metaphosphonimidate formation by an elimination addition mechanism; contrasting behaviour of N,N-dimethyl P-arylphosphonamidic chlorides
作者:Sally Freeman、Martin J. P. Harger
DOI:10.1039/p19870001399
日期:——
The two types of phosphonamidic chloride ArP(O)(Cl)NMe2(5) and ArP(O)(Cl)NHBut(7) have been prepared with Ar = Ph, o-MeC6H4, 2,4,6-Me3C6H2, and 2,4,6-Pri3C6H2. Both types give the expected phosphonic diamide substitution products with PriNH2 and ButNH2 in MeCN, but the two types display contrasting reactivity. With ButNH2 the NMe2 substrates (5) become progressively less reactive as the degree of steric
这两种类型的phosphonamidic氯化物的ARP(O)(Cl)的NME 2(5)和ARP(O)(CL)NHBu吨(7)已经制备用Ar =苯基,ö -MeC 6 ħ 4,2,4, 6-Me 3 C 6 H 2和2,4,6-Pr i 3 C 6 H 2。这两种类型的得到所需膦二酰胺取代产物与镨我NH 2和卜吨NH 2在MeCN,但两种类型的显示对比的反应性。与卜吨NH 2的NME随着空间拥挤程度的增加, 2个底物( 5)的反应性逐渐降低,尽管减少的幅度很小(整体为70倍),但似乎与[ S N 2(P)]缔合机制相符。这些底物反应更快地镨100倍我NH 2,比用卜吨NH 2和镨我NH 2 -Bu吨NH 2竞争性实验中,他们得到几乎完全(99%)从以下受阻镨衍生产物我NH 2。对于NHBu t基材( 7)与卜吨NH 2,有在PH之间和反应性差别不大ö -MeC 6 ħ 4种化合物,以及2,4