Novel C-phosphorylated heterodienes based on pentachloroethyl isocyanate

A preparative method for the synthesis of novel N-phosphorylcarbonyl-and N-alkoxycarbonyltrichloroacetimidoylphosphonates from accessible pentachloroethyl isocyanate was developed. Factors that determine the C/N-selectivity of the phosphorylation of trichloroacetimidoyl chlorides were revealed: phenyl substituents at the P atom and an electron-withdrawing N-alkoxycarbonyl group in imidoyl chloride favored N-phosphorylation, while reactions with silyl phosphite gave exclusively C-phosphorylation products.