Synthesis, Characterization And Catalytic Activity Of Organolanthanide Complexes With2-(2,6-diisopropylphenyl)iminomethylene-8-hydroxyquinolineLigand

Reaction of8-hydroxyquinoline-2-carbaldehyde with1equiv of2,6-Diisopropylaniline in anhydrous ethanol yielded2-（2,6-diisopropylPhenyliminomethylene）-8-hydroxyquinoline （1） in68%yield. Treatment of [（Me3Si）N]II3LnI（-Cl）Li（THF）3[Ln=Yb、Er、Sm] With2equiv of （1） in tol-uene under50oC for24hours, after recrystallization from hexane, gavethree new rare earth metal complexes {1:1-[1:1-2-（2,6-iPr₂C₆H₃）N=CH-8-OC₉H₆N]2Li}Yb[N（SiMe₃）₂]₂（2） in43%yield;{1:1-[1:1-2-（2,6-iPr₂C₆H₃）N=CH-8-OC₉H₆N]₂Li}Er[N（SiMe₃）₂]₂（3） in41%yield;{1:1-[1:1-2-（2,6-iPr₂C₆H₃）N=CH-8-OC₉H₆N]₂Li}Sm[N（SiMe₃）₂]₂（4） in40%yield.Treatment of （MeI3Si）N]3LnII（-Cl）Li（THF）3[Ln=Er、Dy、Y] with1equiv of （1） in toluene under50oC for24hours, after recrystallizationfrom hexane gave three novel four coordinate rare earth metal complexes{1:1-[2-（2,6-iPr₂C₆H₃）N=CH]-8-OC₉H₆N]Li[-N（SiMe₃）₂]}Er[N（SiMe3）₂]₂（5）in42%yield;{1:1-[2-（2,6-iPr₂C₆H₃）N=CH]-8-OC₉H₆N]Li[-N（SiMe₃）2]}Dy[N（SiMe₃）₂]₂（6）in39%yield;{1:1-[2-（2,6-iPr₂C₆H₃）N=CH]-8-OC₉H₆N]Li[-N（SiMe₃）₂]}Y[N（SiMe₃）₂]₂（7） in38%yield.The complexes were characterized by elemental and spectroscopic analyses. The structures of complexes2,3,4,5,6,7were determined byX-ray diffraction.At the same time, the experiments on catalytic activity of the above rareearth metal complexes as catalysts showed that all complexes exhibitedhigh catalytic activity and chemoselectivity on the hydrophosphinylation oftrans-β-nitrostyrene and diphenylphosphine oxide. The best reactionconditions were optimized by examination of solvents, catalyst loadings,temperature and reaction time. The plausible catalytic reaction mechanismwas proposed.