Radical Cations of Phosphorous Amides in Reactions with Alkenes

Electrochemical oxidation of diethyl diethylphosphoramidite and ethyl tetraethylphosphorodiamidite in the presence of alkenes results in formation of amido(1-alkenyl)- and amido(2-alkenyl)phosphonates. Under the same conditions, hexaethylphosphorous triamide forms a dodecaethylhexaaminodiphosphonium salt. Electrochemical oxidation of the above phosphoramidites and -diamidites in the presence of diethyl hydrogen phosphite or O,O-dibutyl hydrogen thiophosphite and an alkene involves addition of (RO)2P(O,S)H at the multiple bond and yields a different ratio of isomeric mono- and diamidoalkenylphosphonates