Reactions of carbene intermediates from the reaction of trialkyl phosphites with dialkyl benzoylphosphonates: intramolecular cyclisations of 2-substituted dialkyl benzoylphosphonates
作者:D. Vaughan Griffiths、Penelope A. Griffiths、Khalku Karima、Belinda J. Whitehead
DOI:10.1039/p19960000555
日期:——
The reaction of dialkyl benzoylphosphonates 1 with trialkyl phosphites leads to the formation of carbene intermediates 3 via the anionic intermediates 2. The carbene intermediates 3 (R = 2-PhO, 2-PhOCH2, and 2-PhS) have been generated by heating the corresponding 2-substituted dialkyl benzoylphosphonates with trimethyl phosphite and their subsequent reactions investigated. Reactions proceed either
二烷基苯甲酰基膦酸酯1与亚磷酸三烷基酯的反应导致通过阴离子中间体2形成卡宾中间体3。卡宾中间体3(R = 2-PhO,2-PhOCH 2和2-PhS)通过加热生成亚磷酸三甲酯形成相应的2-取代的二烷基苯甲酰基膦酸酯及其后续反应。反应通过亚磷酸三甲酯亚分子间卡宾中间体的分子间捕获来进行,以产生新的亚膦酸酯膦酸酯4,或通过涉及卡宾插入取代基中苯环的π-系统的分子内途径进行。使用甲基取代的衍生物进行的研究表明,噻吨基膦酸酯15(X = S,R'= R''= Me)的形成通过 螺二烯中间体14(X = S,R'= R''= Me)。