Rare-earth metal amido complexes supported by bridged bis（β-diketiminato） ligand as efficient catalysts for hydrophosphonylation of aldehydes and ketones

A series of rare-earth metal amides supported by a cyclohexyl-linked bis（β-diketiminato） ligand were synthesized, and theft catalytic activities for hydrophosphonylation of aldehydes and ketones were developed. Reaction of [（Me3Si）2N]3RE（ct- C1）Li（THF）3 with the cyclohexyl-linked bis（13-diketimine） H2L （1） （L = Cy[NC（Me）CHC（Me）NAr]2, Cy = cyclohexyl, Ar = 2, 6-i-Pr2C6H3） gave the rare-earth metal amides LREN（SiMe3）2 （RE = Nd（2）, Sin（3）, Dy（4）, Er（5）, Y（6））. All complexes were fully characterized by elemental, spectroscopic and single-crystal X-ray analyses. Investigation of the catalytic properties of the complexes reveals that these complexes exhibited a high catalytic activity towards the hydrophosphonylation of aldehydes and ketones in the presence of a very low loading of rare-earth metal amides （0.1-1 tool%） at room temperature in a short time.

Syntheses of bimetallic lanthanide bis(amido) complexes stabilized by bridged bis(guanidinate) ligands and their catalytic activity toward the hydrophosphonylation reaction of aldehydes and ketones

A series of bimetallic lanthanide bis(amido) complexes stabilized by bridged bis(guanidinate) ligands {[(Me3Si)2N]2Ln[(RN)2-CN(CH2)2]}2 [R=iPr, Ln=Sm(1), Yb(2), Y(3); R=cyclohexyl(Cy), Ln=Sm(4), and Yb(5)] were synthesized through the metathesis reactions of {Ln(μ-Cl)[N(Si Me3)2]2(THF)}2(Ln=Sm, Yb, Y) with lithium guanidinate {Li[(RN)2CN(CH2)2]}2(R=iPr, Cy), the latter of which was generated in situ by the reaction of carbodiimides with lithium amides. Complexes 1–5 were well characterized by elemental analyses, IR spectra, and(for Complex 3) NMR spectroscopy. The solid-state molecular structures of all of the complexes were determined by single-crystal X-ray analyses with the exception of Complex 3, which showed similar unsolvated centrosymmetric dinuclear structures. Each of the lanthanide centers is four-coordinated with two nitrogen atoms from a guanidinate ligand and two nitrogen atoms from two amido groups. The piperazidine rings adopt chair conformations in all cases. These organolanthanide complexes were found to be efficient catalysts for the hydrophosphonylation reaction of various aldehydes and unactivated ketones and to afford ?-hydroxyphosphonates in high yields under low catalyst loading(0.1 mol%) in a short reaction time.

Asymmetric Pudovik Reaction of Chiral Fluoroalkyl α,β-Unsaturated Ketimines and Diphenyl Phosphite

The asymmetric Pudovik reaction of chiral fluoroalkyl α,β-unsaturated ketimines derivated from(R)-tert-butanesulfinamide and diphenyl phosphite was achieved in the presence of Rb2CO3 at room temperature.A series of fluoroalkylated α-amino phosphonates were prepared in good yields with high diastereoselectivities.