The recent developments in the chemistry of P-zwitterions 2 are discussed.
They include unusual reactions of 2 with HgCl2, ArN3, TosNCO and Alk(Ar)NCX
(X=O,S). The insertion reactions of alkyiso(thio)cyanates into C-C bond ar
e considered. A novel type of the intramolecular electrophilic rearrangemen
ts is described.