A phosphenium‐cation‐mediated formal [3+2]‐cycloaddition reaction of internal alkynes is reported. The reaction proceeds under metal‐free conditions to give the corresponding C−P rearranged benzophospholes regioselectively, even when ortho‐ and para‐substituted arylphosphine oxides are starting substrates. Mechanistic studies by 31P1H} NMR analysis suggest an involvement of three‐membered phosphirenium
据报道内部炔烃有阳离子介导的正式[3 + 2]-环加成反应。即使在邻位和对位取代的芳基膦氧化物为起始底物的情况下,反应也会在无金属条件下进行,从而产生相应的CP重排的苯并磷酰基。通过31 P 1 H} NMR分析进行的机理研究表明,在为苯并磷酰基骨架形成闭环之前,三元磷阳离子种类和C-P重排有关。