Revisiting the reactivity of oximate α-nucleophiles with electrophilic phosphorus centers. Relevance to detoxification of sarin, soman and DFP under mild conditions
作者:François Terrier、Pedro Rodriguez-Dafonte、Eric Le Guével、Gilles Moutiers
DOI:10.1039/b609658c
日期:——
results obtained for reactions at carbon centers, it can be concluded that the observed saturation effect is the reflection of an intrinsic property of the oximate functionality. An explanation of this behavior in terms of an especially strong requirement for desolvation of the oximates prior to nucleophilic attack which becomes more and more difficult with increasing basicity is suggested. This proposal
电位计确定(R1R2)C = NOH官能度的相关pKa值后,使大量肟酸碱与两种模型有机磷酸酯即bis-(4 -硝基苯基)苯基膦酸酯(BNPPP)和双-(4-硝基苯基)甲基膦酸酯(BNPMP),以及三种有毒化合物,即沙林(GB),梭曼(GD)和氟磷酸二异丙酯(DFP),以及30:已测量到70(v / v)的H2O-Me2SO混合物。log k(Ox)vs的相应Bronsted型亲核图。pKa(Ox)揭示了明显的趋势,即肟酸的反应性会随着水溶液中碱度的增加而遭受饱和作用。对于BNPMP和三种有毒酯,这种行为反映在pKa约为9时趋于平稳,但在BNPPP系统中则存在更为戏剧化的情况,其中在pKa约为9时达到最大反应性,随后在较高pKa时速率明显下降。有趣的是,以前由沙林,梭曼和DFP系统的不同作者所报告的许多数据都非常符合我们的数据所建立的曲线布朗斯泰德相关性。根据在碳中心反应获得的该结果和先前的