It was found for the first time that organic alkali metal compounds serve as highly efficient precatalysts for the hydrophosphonylation reactions of aldehydes and unactivated ketones with dialkyl phosphite under mild conditions. For ketone substrates, a reversible reaction was observed, and the influence of catalyst loading and reaction temperature on the reaction equilibrium was studied in detail. Overall, the hydrophosphonylation reactions catalyzed by 0.1 mol % n-BuLi were completed within 5 min for a broad range of substrates and generated a series of α-hydroxy phosphonates in high yields.

Four novel heterobimetallic complexes [REL2]{[(THF)3Li]2(μ-Cl)} stabilized by chiral phenoxy-functionalized prolinolate (RE = Yb (1), Y (2), Sm (3), Nd (4), H2L = (S)-2,4-di-tert-butyl-6-[[2-(hydroxydiphenylmethyl)pyrrolidin-1-yl]methyl]phenol have been synthesized and characterized. These readily available complexes are highly active in catalyzing the epoxidation of α,β-unsaturated ketones, while the enantioselectivity varies according to the ionic radii of the rare earth center. A series of chalcone derivatives were converted to chiral epoxides in 80 → 99% ee at 0 °C using TBHP as the oxidant in the presence of 10 mol % of 1.

Eight rare-earth metal guanidinates supported by a versatile family of chelating amine-bridged bis(phenolate) ligands were synthesized. Metathesis reactions of rare-earth metal chlorides [LnClL 1 (THF)] stabilized by amine-bridged bis(phenolate) ligand L 1 with in situ generated lithium guanidinates in a 1 : 1 2 ) 5 (2)]. Insertion reactions of the yttrium amides bearing bridged bis(phenolate) ligands with 1 equiv of N,N 0 -diisopropylcarbodiimide (DIC) yielded six yttrium guanidinates 2 ] (8), respectively. The behaviors of complexes 1-8 in the polymerization of rac-lactide (LA) and rac-b-butyrolactone (BBL) were also explored. It was found that complexes 1-8 efficiently initiated the ring-opening polymerization (ROP) of rac-LA and rac-BBL in a controlled manner, providing highly heterotactic polylactide (P r up to 0.99) and highly syndiotactic poly(3-hydroxybutyrate) (P r up to 0.82). The framework of the bridge played a significant role in governing the stereoselectivity, while guanidinate groups work as initiating groups.

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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.