Synthesis and Reactions of the Intermediates of the Wittig, Peterson, and their Related Reactions

The title intermediates containing a tetracoordinate B atom, pentacoordinate Si, Ge, Sn, and P atoms, and tetracoordinate S and Se atoms, were successfully synthesized as stable compounds. The X-ray crystallographic analyses of Si, Ge, P, S, and Se compounds indicated that they have a distorted trigonal bipyramidal structure with two oxygen atoms at the apical positions, but those of B, Sn, and another type of Ge compounds demonstrated that they have a very distorted tetrahedral boron, a nearly square pyramidal tin, and a tetrahedral germanium interacting with an oxido anion, respectively. On heating all compounds containing group 13, 14, and 15 elements underwent the Wittig-type reaction to give the corresponding olefin. It was suggested that a tetracoordinate 1,2λ4-oxathietane is an intermediate of the Corey-Chaykovsky reaction.