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|Section2= |Section3= }} Phosphole is the organic compound with the chemical formula C4H4PH; it is the phosphorus analog of pyrrole. The term phosphole also refers to substituted derivatives of the parent heterocycle. These compounds are of theoretical interest but also serve as ligands for transition metals and as precursors to more complex organophosphorus compounds. The first phosphole, pentaphenylphosphole, was reported in 1953, and the parent phosphole itself was first described in 1987.〔''A Guide to Organophosphorus Chemistry'' Louis D. Quin 2000 John Wiley & Sons ISBN 0-471-31824-8〕 The usual route to phospholes is via the McCormack reaction, involving the addition of a 1,3-diene to a phosphonous chloride followed by dehydrohalogenation. Phenylphospholes can be prepared via zirconacyclopentadienes by reaction with PhPCl2. Unlike the related 5-membered heterocycles pyrrole, thiophene, and furan, the aromaticity of phospholes is diminished, reflecting the reluctance of phosphorus to delocalize its lone pair. For example, phospholes undergo Diels-Alder reactions with electrophilic alkynes. : == Reactivity == Phosphole chemistry is hampered by its sensitivity to moisture. 2,5-diphenyl phospholes can be functionalised by deprotonation followed by P-acylation then a 1H, 2H, 3H phospholide equilibrium resulting in a 1:3 shift of the acyl group. Phospholes can also be turned into β-functional phosphabenzenes (phosphinines, or phosphorine) via functionalisation by imidoyl chloride and insertion. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Phosphole」の詳細全文を読む スポンサード リンク
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