作者:Josiel B. Domingos、Elisane Longhinotti、Clifford A. Bunton、Faruk Nome
DOI:10.1021/jo034348z
日期:2003.9.1
phosphonohydroxylamine and eventually inorganic phosphate; (3) a novel rearrangement with intramolecular aromatic nucleophilic substitution involving a cyclic intermediate and migration of the 2,4-dinitrophenyl group from O to N. Values of k(obs) increase modestly with pH > 10, the reaction is biphasic, and the yield of DNP increases. An increase in [NH(2)OH] also increases the yield of DNP, due largely to accelerated
对于pH范围4-12的水中的羟胺对磷酸二(2,4-二硝基苯基)酯(BDNPP)进行去磷酸化,观察到的一阶速率常数k(obs)最初随pH的增加而增加,但为pH -在pH 7.2和pH 10之间独立。最初的BDNPP被非离子型NH(2)OH(<0.2 M)裂解涉及到OH基团的攻击并遵循一级动力学,但是BDNPP的整体初始反应释放了约5%。1.7摩尔的2,4-二硝基苯氧离子(DNP)。该初始反应生成短寿命的O-磷酸化羟胺2,然后进行三个可能的反应:(1)2与羟胺反应,生成2,4-二硝基苯基磷酸酯(DNPP,3),随后形成DNP;(2)第二DNP基团的分子内置换和环状中间体的快速分解形成膦酰基羟胺,最终形成无机磷酸盐;(3)分子内芳族亲核取代的新型重排,涉及环状中间体和2,4-二硝基苯基从O到N的迁移.k(obs)的值随pH> 10适度增加,反应是双相的,且DNP的产量增加。[NH(2)OH]的增