Results of research into four-membered 2-halo-1,2λ
5-oxaphosphetane phosphorus(V)-heterocycles are presented. The preparation of 2-halo-1,2λ
5-oxaphosphetanes by reaction of
P-haloylides with carbonyl compounds is described. The mechanism of asynchronous [2+2]-сycloaddition of ylides to aldehydes was proposed on the base of low-temperature
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Results of research into four-membered 2-halo-1,2λ
5-oxaphosphetane phosphorus(V)-heterocycles are presented. The preparation of 2-halo-1,2λ
5-oxaphosphetanes by reaction of
P-haloylides with carbonyl compounds is described. The mechanism of asynchronous [2+2]-сycloaddition of ylides to aldehydes was proposed on the base of low-temperature NMR investigations. 2-Halo-1,2λ
5-oxaphosphetanes were isolated as individual compounds and their structures were confirmed by
1Н-,
13C-,
19F- and
31Р-NMR spectra. These compounds are convenient reagents for preparing of various organic and organophosphorus compounds hardly available by other methods. Chemical and physical properties of the 2-halo-1,2λ
5-oxaphosphetanes are reviewed. The 2-chloro-1,2λ
5-oxaphosphetanes, rearrange with formation of 2-chloroalkyl-phosphonates or convert into
trans-phosphorylated alkenes depending on the substituents at the α-carbon atom. Prospective synthetic applications of 2-halo-1,2λ
5-oxaphosphetanes are analyzed. The 2-halo-1,2λ
5-oxaphosphetanes may be easily converted to various alkenylphosphonates: allyl- or vinylphosphonates, phosphorus ketenes, thioketenes, ketenimines.
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