Chapter 6 - Other five-membered ring compounds with one hetero atom in the ring from groups III, IV and V

Abstract

Publisher Summary This chapter discusses other five-membered ring compounds with one hetero atom in the ring from groups, 3, 4 and 5, such as the phosphorus compounds, silicon compounds, germanium compounds, and compounds containing aluminum, boron, antimony and tin as the hetero atom. The study of phosphorus compounds involves a review of the synthesis, properties and reactions of the phospholes, phospholenes and phospholanes, and polynuclear, fused-ring compounds such as dibenzophospholes. The reaction of pyrocatechol phosphorochloridite with a diene in a closed vessel during 3-4 days gives a crystalline adduct, identified as 1-halogeno-1,1-(o-phenylenedioxy)-3-phospholene. The normally expected Arbuzov rearrangement is prevented by the strength of the bond between O and the aromatic ring. Similar adducts have been obtained using pyrocatechol phosphorobromidite and phosphorofluoridite. Similarly, silicon compounds are covered under the mononuclear compounds, such as silacyclopentadienes; siloles, silacyclopentenes, silacyclopentanes and fused-ring compounds, such as 1,1-diphenyi-1-silaindan, 2,3-benzo-1,1-diphenylsilacyclopentane. Germacyclopentane, is prepared by treating dichlorogermacyclopentane with lithium tetrahydridoaluminate. The germacyclopentane ring is stable to the action of acids and bases, except that sulfuric acid opens the ring. The interaction between triphenylaluminum and diphenylacetylene at 200° leads to the formation of benzene and 1,2,3-triphenylbenzaluminole.