title: Lanthanide anilido complexes: synthesis, characterization, and use as highly efficient catalysts for hydrophosphonylation of aldehydes and unactivated ketones.
abstract: Lanthanide anilido complexes stabilized by the 2,6-diisopropylanilido ligand have been synthesized and characterized, and their catalytic activity for hydrophosphonylation reaction was explored. A reaction of anhydrous LnCl3 with 5 equivalents of LiNHPh-(I)Pr2-2,6 in THF generated the heterobimetallic lanthanide-lithium anilido complexes (2,6-(I)Pr2PhNH)5LnLi2(THF)2 [Ln = Sm(1), Nd(2), Y(3)] in good isolated yields. These complexes are well characterized by elemental analysis, IR, NMR (for complex ) and single-crystal structure determination. Complexes 1 - 3 are isostructural. In these complexes, the lanthanide metal ion is five-coordinated by five nitrogen atoms from five 2,6-diisopropylanilido ligands to form a distorted trigonal bipyramidal geometry. The lithium ion is coordinated by two nitrogen atoms from two 2,6-diisopropylanilido ligands, and one oxygen atom from a THF molecule. It was found that these simple lanthanide anilido complexes are highly efficient for catalyzing hydrophosphonylation reactions of various aldehydes and unactivated ketones to generate α-hydroxyphosphonates in good to excellent yields (up to 99%) within a short time (5 min for aldehydes, 20 min for ketones). Furthermore, the mechanism of hydrophosphonylation reactions has also been elucidated via(1)H NMR monitoring of reaction.
authors.affiliation: Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Dushu Lake Campus, Soochow University, Suzhou 215123, People's Republic of China. yuandan@suda.edu.cn yaoym@suda.edu.cn.
authors.forename: Chengwei
authors.initials: C
authors.lastname: Liu
authors.forename: Qinqin
authors.initials: Q
authors.lastname: Qian
authors.forename: Kun
authors.initials: K
authors.lastname: Nie
authors.forename: Yaorong
authors.initials: Y
authors.lastname: Wang
authors.forename: Qi
authors.initials: Q
authors.lastname: Shen
authors.forename: Dan
authors.initials: D
authors.lastname: Yuan
authors.forename: Yingming
authors.initials: Y
authors.lastname: Yao
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D000813:Anilides / Q000737:chemistry*; D002384:Catalysis; D056831:Coordination Complexes / Q000138:chemical synthesis* / Q000737:chemistry; D007659:Ketones / Q000737:chemistry*; D007811:Lanthanum / Q000737:chemistry*; D015394:Molecular Structure; D063065:Organophosphonates / Q000737:chemistry*
chemical_list: D000447:Aldehydes; D000813:Anilides; D056831:Coordination Complexes; D007659:Ketones; D063065:Organophosphonates; D007811:Lanthanum