Über intramolekulare Donator-Akzeptor-Wechselwirkungen in N,N′-Dimethylharnstoff-Derivaten des Phosphors / Intramolecular Donor-Acceptor Interactions in N,N′-Dimethylurea Derivatives of Phosphorus

The reaction of 1 with N, N′-dimethyl-N, N′-bis(trimethyIsilyl)urea, 2 has furnished the compound Me2NCH2CH2N(Me)P(NMe)2C(:O), 3. Following oxidation o f phosphorus in 3 through several reagents, intramolecular donor-acceptor interactions were observed when an electronegative group was bonded to phosphorus; this group, activating the phosphorus atom, should be well polarizable in solution and should readily depart from the molecule as an anion. The unusual spirophosphoranes 8, 11 and 12 could thus be synthesized. The reaction of equimolar quantities of MeOCH2CH2OPCl2, 15 with 2 has furnished 16 which is related to 3. Reaction of 15 with excess 2 constitutes a new mode o f formation of the previously reported diphosphorus compound 17.