of sodium, lithium, barium, and magnesium perchlorate in acetone solution on the rates of different Diels-Alder reactions were kinetically investigated, 13 C-NMR spectroscopy being used as a tool to infer the mechanism of coordination of the solvated cations acting as catalysts. The Diels-Alder reactions, whose rates increase with increasing electrophilic character of the solvent, are strongly accelerated
钠、
锂、
钡和
镁在
丙酮溶液中对不同 Diels-Alder 反应速率的影响进行了动力学研究,13 C-NMR 光谱被用作推断溶剂化阳离子的配位机制的工具催化剂。Diels-Alder 反应的速率随着溶剂亲电特性的增加而增加,在
金属阳离子的存在下强烈加速。阳离子活性的顺序,Mg 2+ >Ba 2+ ≥Li + >Na + ,与它们各自的电荷:半径比的顺序平行。以亲核或非特异性溶剂效应为特征的 Diels-Alder 反应对任何
金属阳离子的存在几乎不敏感,因为它不能充当亲电子试剂