This work reports the first method for the synthesis of α-hydroxyphosphonates from aldehydes catalyzed by cyclopentadienyl ruthenium(II) complexes. The best results were obtained using the system HP(O)(OEt)₂/[RuClCp(PPh₃)₂] (5 mol%), affording the α-hydroxyphosphonates in good to excellent yields with high chemoselectivity. The catalyst [RuClCp(PPh₃)₂] can be used for at least 12 catalytic cycles with excellent activity and the reactions were carried out under solvent free conditions. DFT calculations were performed to rationalize the mechanism showing that the barriers associated with the H-phosphonate tautomer, HP(O)(OR)₂ are unrealistically high. This led us to propose that the catalyst promotes the tautomerization towards phosphite, P(OH)(OR)₂, via P-atom coordination, which accounts for the observed reactivity.

这项工作报告了由环戊二烯基钌（II）络合物催化的醛合成α-羟基膦酸酯的第一种方法。使用系统HP（O）（OEt）₂ / [RuClCp（PPh ₃）₂ ]（5 mol％）可获得最佳结果，从而以良好的化学选择性提供了高至优异产率的α-羟基膦酸酯。催化剂[RuClCp（PPh ₃）₂ ]可以以优异的活性用于至少12个催化循环，并且反应在无溶剂条件下进行。进行DFT计算以合理化机理，显示与H-膦酸酯互变异构体HP（O）（OR）₂相关的屏障高得离谱。这使我们建议将催化剂促进朝亚磷酸酯，P的互变异构（OH）（OR）₂，经由P-原子协调，其占所观察到的反应性。