Cyclic Oxyphosphoranes

The review deals with a new interesting field in the chemistry of organophosphorus compounds – cyclic derivatives of pentacoordinate phosphorus containing at least one endocyclic P–O bond and not containing halogens. The principal types of cyclic oxyphosphoranes with four-, five-, and six-membered rings, spirophosphoranes, and phosphoranes of the condensed and prismatic types have been examined. The methods of synthesis and chemical reactions of cyclic phosphoranes are described: condensation with carbonyl compounds, hydrolysis, alcoholysis, thermal stability, etc. Physicochemical studies on phosphoranes have been undertaken to establish their structures and to investigate their stereochemistry. X-ray diffraction, infrared spectroscopy, ¹H NMR, and ³¹P NMR have been used for these purposes. The groups linked to phosphorus are capable of permutational isomerisation which can occur via the mechanism of the Berry pseudorotation or via turnstile rotation.
The bibliography includes 264 references.