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  

作　　者：Kun Nie Chengwei Liu Yong Zhang Yingming Yao 

机构地区：[1]School of Chemistry and Chemical Engineering, Taishan University [2]Key Laboratory of Organic Synthesis of Jiangsu Province [3]College of Chemistry, Chemical Engineering and Materials Science,Soochow University

出　　处：《Science China Chemistry》2015年第9期1451-1460,共10页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China(21132002,21372172,21402138);the Major Research Project of the Natural Science Foundation of the Jiangsu Higher Education Institutions(14KJA150007);the Qing Lan Project

摘　　要：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.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 α-hydroxyphosphonates in high yields under low catalyst loading（0.1 mol%） in a short reaction time.

关 键 词：bimetallic lanthanide complex bridged bis（guanidinate） ligand hydrophosphonylation reaction aldehyde ketone 

分 类 号：O641.4[理学—物理化学] O621.251[理学—化学]