Controlled Monohalogenation of Phosphonates, Part II: Preparation of Pure Diethyl α-Monohalogenated Alkylphosphonates
作者:Bogdan Iorga、Frédéric Eymery、Philippe Savignac
DOI:10.1055/s-2000-6375
日期:——
The reaction of diethyl alkylphosphonates with chlorotrimethylsilane in the presence of lithium diisopropylamide leads to the corresponding diethyl 1-lithio(trimethylsilyl)alkylphosphonates which are cleanly halogenated (X = F, Cl, Br, I) with electrophilic reagents and then deprotected to give pure diethyl a-monohalogenoalkylphosphonates. The reaction has been extended by the onepot conversion of
在二异丙基氨基锂存在下,烷基膦酸二乙酯与三甲基氯硅烷反应生成相应的 1-锂硫(三甲基甲硅烷基)烷基膦酸二乙酯,该二乙酯用亲电子试剂完全卤化(X = F、Cl、Br、I),然后脱保护得到纯二乙基α-单卤代烷基膦酸酯。通过将磷酸三乙酯单锅转化为α-单卤代丁基膦酸二乙酯,该反应得到了扩展,总产率为 85-97%。