Synthesis and characterization of ytterbium guanidinates stabilized by bridged bis(phenolate) ligand and their application for the hydrophosphonylation reaction of aldehydes

Zeng, Tinghua; Qian, Qinqin; Wang, Yaorong; Yao, Yingming; Shen, Qi

doi:10.1016/j.jorganchem.2014.12.021

Cited by 7 publications

(3 citation statements)

References 27 publications

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“…Although some trivalent rare-earth Ln{ONXO R1,R2 } complexes have been used to promote a few other reactions such as hydrophosphonylation of aldehydes, group transfer polymerizations of vinylic monomers (2-vinylpyridine, 2-isopropenyl-2-oxazoline, vinylphosphonates, N,N -dimethylacrylamide), or more recently styrene and trans -1,4-isoprene (co)polymerizations, this class of complexes has been developed almost exclusively for catalyzing/initiating cyclic ester ROP reactions. Our group first reported in 2003 that the prototypic amide complex Y{ON(OMe)O t Bu, t Bu }(N(SiHMe 2 ) 2 )(THF) catalyzes sluggishly the polymerization of methyl methacrylate to give isotactic-rich PMMA but is actually very active for the ROP of ε-caprolactone (CL): 400 equiv of this monomer was quantitatively polymerized within 1 min at room temperature to afford poly(ε-caprolactone) (PCL) with number-average molecular weights ( M n ) close to the expected values, calculated from the monomer-to-yttrium ratio, yet with broad dispersities ( M w / M n = 2.4–4.1) .…”

Section: Application Of Rare-earth Ln{onxor1r2} Complexes In Rop Cat...mentioning

confidence: 79%

“…39 Amidinate and guanidinate complexes Ln{ONXO R1,R2 }-((R 4 )C(NR 3 ) 2 ), although not as efficient ROP initiators as the amido derivatives (vide infra), were readily prepared by salt metathesis approaches from the corresponding chlorides and alkali amidinates/guanidinates (Scheme 12). 27,40,41 All of them feature monomeric structures in the solid state, with solventfree, six-coordinated metal centers. Interestingly, Marques, Martins, et al showed that reaction of an aryl complex with excess acetonitrile proceeded with the insertion/coupling of two CH 3 CN molecules and the C 6 H 4 CH 2 NMe 2 group to produce a β-diketiminate complex (Scheme 13).…”

Section: Organometallicsmentioning

confidence: 99%

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Rare-Earth Complexes Supported by Tripodal Tetradentate Bis(phenolate) Ligands: A Privileged Class of Catalysts for Ring-Opening Polymerization of Cyclic Esters

2015

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International audienceTripodal dianionic diamino- or amino-alkoxy-bis(phenolate) ligands \ONXOR1,R2\ (X = NR2, OR) constitute a privileged class of ligands which has found much interest in combination with group 3 and group 4 metals for generating highly efficient polymn. catalysts. This account article describes the structural variety of and synthetic routes toward trivalent rare-earth complexes incorporating such \ONXOR1,R2\ ancillaries along with reactive amido, alkyl, alkoxide, amidinate, guanidinate, halide, and borohydride groups. The chem. of related divalent rare-earth complexes is also included. This class of Ln\ONXOR1,R2\(R) complexes features outstanding performance in the ring-opening polymn. (ROP) of cyclic esters. Examples of their high reactivity, which has allowed enlarging the scope of ROP reactions to monomers that are difficult to ring-open, and of their ability to control reactions are provided. A particular emphasis is given on their propensity to fine-tune the stereoselectivity of ROP reactions involving chiral cyclic esters, by modifying the ortho substituents on the phenolate rings. The assocd. mechanistic issues which have evidenced steric and much less common electronic interactions are discussed

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Section: Application Of Rare-earth Ln{onxor1r2} Complexes In Rop Cat...mentioning

confidence: 79%

Section: Organometallicsmentioning

confidence: 99%

Rare-Earth Complexes Supported by Tripodal Tetradentate Bis(phenolate) Ligands: A Privileged Class of Catalysts for Ring-Opening Polymerization of Cyclic Esters

2015

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“…Although guanidinato ligands have already been reported to stabilize rare-earth metal complexes, they were not employed as initiating groups in ROP of cyclic esters. 8c, [38][39][40] Complexes bearing both bis(phenolate) and guanidinato ligands are thus tested in initiating the ROP of described as distorted octahedron, in which O1, O2, N1, and N4 atoms occupy equatorial positions, and N2 and N3 atoms occupy axial positions. The N2-Yb-N3 angles are found to be 163 and 165 , respectively.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of rare-earth metal guanidinates stabilized by amine-bridged bis(phenolate) ligands and their application in the controlled polymerization of rac-lactide and rac-β-butyrolactone

et al. 2015

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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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ChemInform Abstract: Synthesis and Characterization of Ytterbium Guanidinates Stabilized by Bridged Bis(phenolate) Ligand and Their Application for the Hydrophosphonylation Reaction of Aldehydes.

et al. 2015

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Synthesis and Characterization of Ytterbium Guanidinates Stabilized by Bridged Bis(phenolate) Ligand and Their Application for the Hydrophosphonylation Reaction of Aldehydes. -Ytterbium guanidinates are shown to be highly efficient catalysts for the hydrophosphonylation of various aldehydes (16 examples) under mild conditions. -(ZENG, T.; QIAN, Q.; WANG, Y.; YAO*, Y.; SHEN, Q.; J. Organomet. Chem. 779 (2015) 14-20, http://dx.doi.org/10.1016/j.jorganchem.2014.12.021 ; Coll. Chem., Chem. Eng. Mater. Sci., Soochow Univ., Suzhou 215123, Peop. Rep. China; Eng.) -M. Paetzel 25-230

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Synthesis and characterization of ytterbium guanidinates stabilized by bridged bis(phenolate) ligand and their application for the hydrophosphonylation reaction of aldehydes

Cited by 7 publications

References 27 publications

Rare-Earth Complexes Supported by Tripodal Tetradentate Bis(phenolate) Ligands: A Privileged Class of Catalysts for Ring-Opening Polymerization of Cyclic Esters

Rare-Earth Complexes Supported by Tripodal Tetradentate Bis(phenolate) Ligands: A Privileged Class of Catalysts for Ring-Opening Polymerization of Cyclic Esters

Synthesis and characterization of rare-earth metal guanidinates stabilized by amine-bridged bis(phenolate) ligands and their application in the controlled polymerization of rac-lactide and rac-β-butyrolactone

ChemInform Abstract: Synthesis and Characterization of Ytterbium Guanidinates Stabilized by Bridged Bis(phenolate) Ligand and Their Application for the Hydrophosphonylation Reaction of Aldehydes.

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