Synthetic procedures for alkanimidoylphosphoryl derivatives with α-hydrogen atoms in the N-alkyl radical are developed. Data on the effect of substituents at the carbon and phosphorus atoms on the facility of prototropic transitions in the C=N-C triad are summarized. The most facile proton transfer occurs in the N-benzyl derivatives, and the prototropic isomer is the more stable, the stronger the electron-acceptor power of the substituent at the sp 3-carbon atom of the azaallyl triad. The proton transfer in N-(α-phenethyl)-trifluoroacetimidoylphosphonates proceeds selectively, which allows preparation of enantiomerically enriched derivatives of α-aminotrifluoroethylphosphonic acid. A specific effect of substituents at the phosphorus atom on the prototropism attendant on phosphorylation of imidoyl chlorides is demonstrated.
开发了含有α-氢原子的N-烷基自由基的烷基
脲膦酰基衍
生物的合成方法。总结了碳原子和
磷原子上的取代基对C=N-C三元组中质子转移便利性的影响数据。在N-苄基衍
生物中,质子转移最为容易,随着位于氮杂烯三元组的sp³碳原子上的取代基的电子受体能力增强,质子异构体愈加稳定。在N-(α-苯乙基)-三
氟乙酰基
脲膦酸酯中,质子转移选择性进行,这使得能够制备富含对映体的α-
氨基三
氟乙基膦酸的衍
生物。证实了
磷原子上取代基对
氯脲酰化反应中伴随的质子转移的特定影响。