二(β-二亚胺基)二价稀土配合物催化醛/酮与亚磷酸二乙酯的氢磷化反应

Bis(β-diketiminato) Lanthanide(Ⅱ) Complexes-Catalyzed Hydrophosphonylation of Aldehydes/Ketones and Diethyl Phosphite

研究了一系列二(β-二亚胺基)二价稀土配合物[Eu(L^(2,6-ipr2))_2·CH_3C_6H_5,L^(2,6-ipr2)=[N(2,6-^(i)Pr_2C_6H_3)C(Me)]_2CH^-(1);Eu(L^(2,6-Me2))_2(THF),L^(2,6-Me2)=[N(2,6-Me_2C_6H_3)C(Me)]_2CH^-(2);Eu(L^(2,4,6-Me3))_2(THF),L^(2,4,6-Me3)=[N(2,4,6-Me_3C_6H_2)-C(Me)]_2CH^-(3);Eu(L^(2,6-ipr2)Ph)2,L^(2,6-ipr2)Ph=[(2,6-iPr_2C_6H3_)NC(Me)CHC(Me)N(C_6H_5)]–(4);Sm(L^(2,6-ipr2))_2·CH_3C_6H_5(5);Yb(L^(2,6-ipr2)Ph)2(6);Yb(L^(2-Me))2(THF),L^(2-Me)=[N(2-Me C6H4)C(Me)]2CH–(7)]对醛/酮与亚磷酸二乙酯的氢磷化反应的催化行为.发现所有配合物都可以在温和条件下,高效地催化芳醛以及杂环芳醛与亚磷酸二乙酯的氢磷化反应,在催化剂用量为0.08 mol%,25℃,无溶剂条件下反应5 min,α-羟基膦酸酯的收率可以达到90%~99%.催化活性有赖于β-二亚胺基的结构,其活性顺序为L^(2,6-Me2)<L^(2,4,6-Me3)<L^(2,6-ipr2)≈L^(2,6-ipr2)Ph.该催化体系具有优秀的醛底物适应能力.这类二价稀土配合物也可以有效地催化未活化的酮与亚磷酸二乙酯的反应,并显示良好的底物适应能力.

The hydrophosphonylation of aldehydes/ketones was explored by use of seven bis（β-diketiminato） lanthanide（Ⅱ） complexes[Eu（L^2,6-ipr2）2·CH3C6H5, L^2,6-ipr2=[N（2,6-iPr2C6H3）C（Me）]2CH^- （1）; Eu（L^2,6-Me2）2（THF）, L^2,6-Me2=[N（2,6-Me2C6H3）C（Me）]2CH^- （2）; Eu（L^2,4,6-Me3）2（THF）, L^2,4,6-Me3=[N（2,4,6-Me3C6H2）C（Me）]2CH^- （3）; Eu（L^2,6-ipr2Ph）2, L^2,6-ipr2Ph=[（2,6-iPr2C6H3）NC（Me）CHC（Me）N（C6H5）]^-（4）; Sm（L^2,6-ipr2）2·CH3C6H5 （5）; Yb（L^2,6-ipr2Ph）2 （6）; Yb（L^2-Me）2（THF）, L2-Me=[N（2-MeC6H4）C（Me）]2CH^- （7）] as the catalysts. All complexes were found to be able to catalyze the hydrophosphonylation between aromatic or heterecycle aldehyde and diethyl phosphite with high activity under wild conditions. All the reactions gave the products in 90%-99% yields using 0.08 mol% of complex 7 at 25℃ under solvent-free. The catalyst activity was found to depend on the β-diketiminato ligands with the sequence of L^2,6-Me2〈L^2,4,6-Me3M〈L^2,6-ipr2≈L^2,6-ipr2Ph. This catalyst system showed a wide scope of aldehydes. Besides, bis（β-diketiminato） lanthanide（Ⅱ） complexes could also efficiently catalyze the hy-drophosphonylation of unactive ketones with diethyl phosphite and showed a good substrate scope.