Ｗｉｔｔｉｇ反応，Ｐｅｔｅｒｓｏｎ反応および関連する反応中間体の合成と構造

Abstract

Pentacoordinate oxaphosphetanes, oxasiletanides, oxagermetanides, oxastannetanides, and tetracoordinate oxaboretanides were successfully synthesized as stable intermediates of the Wittig reaction, the Peterson reaction, Peterson-type reactions, and boron-Wittig reaction, respctively Tetracoordinate and pentacoordinate oxathietanes, tetracoordinate oxaselenetanes and pentacoordinate azaphosphetidines were also synthesized as their sulfur and selenium-analogs, and aza-analog of oxaphosphetanes. The X-ray crystallographic analyses of Si, Ge, P, S, and Se compounds indicated that they have a distorted trigonal bipyramidal structure with two apical oxygen atoms, 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 strongly interacting with an oxido anion, respectively. Expectedly, on heating all compounds containing group 13, 14, and 15 elements underwent the Wittig-type reaction to give the corresponding olefins. Although the thermolysis of oxachalcogenetanes with a tetracoordinate and pentacoordinate S and Se centers gave no olefin, it was suggested that the former compounds are intermediates of the Corey-Chaykovsky reaction of sulfur ylides.