Reactivity of 3-Imino-Functionalized Indoles with Rare-Earth-Metal Amides: Unexpected Substituent Effects on C–H Activation Pathways and Assembly of Rare-Earth-Metal Complexes

Zhu, Xiancui; Li, Yang; Wei, Yun; Wang, Shaowu; Zhou, Shuangliu; Zhang, Lijun

doi:10.1021/acs.organomet.6b00221

Cited by 22 publications

(7 citation statements)

References 78 publications

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“…Most of the clinically applicable drugs are also amines or amine derivatives. Many applied metal complexes or catalysts contain amines or their derivatives as supporting ligands . Therefore, the mastery of the synthesis of amines is an essential step in both academic and industrial fields …”

Section: Introductionmentioning

confidence: 99%

Well-Defined Amidate-Functionalized N-Heterocyclic Carbene -Supported Rare-Earth Metal Complexes as Catalysts for Efficient Hydroboration of Unactivated Imines and Nitriles

et al. 2018

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Four amidate-functionalized N-heterocyclic carbene (NHC) rare-earth metal amido complexes [(κ 2 -N,O-κ 1 -L) 2 REN(SiMe 3 ) 2 ] (L = 1-(C 6 H 5 CONCH 2 CH 2 )-3-(CH 3 ) 3 C 6 H 2 (N(CH) 2 NC)) [RE = Er (1), Y (2), Dy (3), Gd (4)] were synthesized by one-pot reactions of 2 equiv of (1-(C 6 H 5 CONHCH 2 CH 2 )-3-(CH 3 ) 3 C 6 H 2 -(N(CH) 2 NCH))Br (H 2 LBr) with 5 equiv of KN(SiMe 3 ) 3 followed by treatment with 1 equiv of RECl 3 in tetrahydrofuran at −40 °C. These complexes were fully characterized, and their catalytic activities toward hydroboration of unactivated imines and nitriles were investigated, and it was found that these complexes displayed excellent activities as well as remarkable functional group compatibility for imine and nitrile substrates such as halo-, alkyl-, hydroxyl-, N,N-dimethylamino-, and nitro-substituents. Among those, the chemoselectivity for this reaction among the common unsaturated functional groups was achieved in the order CO ≫ CN > CN > CO 2 Et > CC in the current catalytic system, which may facilitate their further application in synthetic chemistry.

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Section: Introductionmentioning

confidence: 99%

Well-Defined Amidate-Functionalized N-Heterocyclic Carbene -Supported Rare-Earth Metal Complexes as Catalysts for Efficient Hydroboration of Unactivated Imines and Nitriles

et al. 2018

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“…The solid-state structure of 7a was determined by singlecrystal X-ray diffraction, which revealed that the bond distances of Y1−N2 [2.350( 5) Å] and Y1−N4 [2.356(6) Å] are almost same, while they are significantly shorter than that of Y1−N3 [2.526( 4) Å], similar to that observed in 1a (Figure 4). The new C15−C24 [1.470( 5) Å] bond distance is slightly shorter than that of C32−C40 [1.499( 5) Å], whereas it is significantly shorter than those from 1.555(6) to 1.543(11) Å in binuclear rare-earth-metal amido complexes, 23 probably because of the partly electronic delocalization on these N5− O1−C24−C15−C16−N2 atoms. The bridging Y−O bond distances of 2.244(6) and 2.348(5) Å are comparable to those from 2.279(2) to 2.316(2) Å in a 2-amidate-functionalized indolylyttrium complex.…”

Section: ■ Results and Discussionmentioning

confidence: 93%

Rare-Earth-Metal-Complex-Catalyzed Hydroalkoxylation and Tandem Hydroalkoxylation/Cyclohydroamination of Isocyanates: Synthesis of Carbamates and Oxazolidinones

Zhu

Yang

et al. 2022

Inorg. Chem.

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Novel N,N,N-tridentate β-diketiminato rare-earth-metal dialkyl complexes LRE(CH2SiMe3)2 [RE = Y (1a), Gd (1b), Yb (1c), Lu (1d); L = MeC(NDipp)CHC(Me)N(CH2)2NC4H8, where Dipp = 2,6- i Pr2C6H3] have been conveniently synthesized by one step from reactions of the rare-earth-metal trialkyl complexes RE(CH2SiMe3)3(THF)2 (THF = tetrahydrofuran) with a pyrrolidine-functionalized β-diketiminate HL, and their catalytic behaviors toward hydroalkoxylation and tandem hydroalkoxylation/cyclohydroamination of isocyanates have been described. These rare-earth-metal catalysts exhibited high efficiency in the hydroalkoxylation of isocyanates, providing a variety of N-alkyl and N-aryl carbamate derivatives under mild reaction conditions with a rather low catalyst loading (0.04 mol %). More significantly, they can promote a tandem hydroalkoxylation/cyclohydroamination reaction between terminal and internal propargylic alcohols with substituted arylisocyanates, leading to the efficient synthesis of methylene and (Z)-selective arylidene oxazolidinones in good-to-high yields via consecutive C–O and C–N bond formation. The stoichiometric reaction of 1a with p-tolylisocyanate generated an unusual dinuclear yttrium complex, {[η2-(4-MePhNCO)(CH2SiMe3)]Y[μ-η2:η1:η1-(4-MePhNCO)CC(Me)(NDipp)C(Me)N(CH2)2NC4H8]}2 (7a), with two different amidate units, which underwent an sp2 C–H bond activation of the β-diketiminato backbone, followed by the insertion of isocyanate.

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“…Although no X-ray-diffraction-quality crystals were obtained for the [OC 4 F 9 ] − complexes 2-Ln (Ln = Eu, Gd, Dy), ESI-MS data are consistent with the assigned formulas for all. On the basis of the photoluminescence data (vide infra) and scarcity of nonpolymeric four-coordinate complexes of Eu, − Gd, ,− and Dy ,,− in the literature, it is proposed that 2-Ln also bears two THF ligands, as seen in 1-Ln , such that the solution structures are six-coordinate. In the absence of crystallographic data for 2-Ln , it is unknown whether the symmetry observed in 1-Ln , which results in only three unique Ln–O distances per complex, is maintained.…”

Section: Resultsmentioning

confidence: 99%

Luminescence of Lanthanide Complexes with Perfluorinated Alkoxide Ligands

et al. 2020

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Four groups of rare-earth complexes, comprising 11 new compounds, with fluorinated O-donor ligands ([K(THF)6][Ln(OC4F9)4(THF)2] (1-Ln; Ln = Ce, Nd), [K](THF) x [Ln(OC4F9)4(THF) y ] (2-Ln; Ln = Eu, Gd, Dy), [K(THF)2][Ln(pinF)2(THF)3] (3-Ln; Ln = Ce, Nd), and [K(THF)2][Ln(pinF)2(THF)2] (4-Ln; Ln = Eu, Gd, Dy, Y) have been synthesized and characterized. Single-crystal X-ray diffraction data were collected for all compounds except 2-Ln. Species 1-Ln, 3-Ln, and 4-Ln are uncommon examples of six-coordinate (Eu, Gd, Dy, and Y) and seven-coordinate (Ce and Nd) LnIII centers in all-O-donor environments. Species 1-Ln, 2-Ln, 3-Ln, and 4-Ln are all luminescent (except where Ln = Gd and Y), with the solid-state emission of 1-Ce being exceptionally blue-shifted for a Ce complex. The emission spectra of the six Nd, Eu, and Dy complexes do not show large differences based on the ligand and are generally consistent with the well-known free-ion spectra. Time-dependent density functional theory results show that 1-Ce and 3-Ce undergo allowed 5f → 4d excitations, consistent with luminescence lifetime measurements in the nanosecond range. Eu-containing 2-Eu and 4-Eu, however, were found to have luminescence lifetimes in the millisecond range, indicating phosphorescence rather than fluorescence. The performance of a pair of multireference models for prediction of the Ln = Nd, Eu, and Dy absorption spectra was assessed. It was found that spectroscopy-oriented configuration interaction as applied to a simplified model in which the free-ion lanthanide was embedded in ligand-centered Löwdin point charges performed as well (Nd) or better (Eu and Dy) than canonical NEVPT2 calculations, when the ligand orbitals were included in the treatment.

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Reactivity of 3-Imino-Functionalized Indoles with Rare-Earth-Metal Amides: Unexpected Substituent Effects on C–H Activation Pathways and Assembly of Rare-Earth-Metal Complexes

Cited by 22 publications

References 78 publications

Well-Defined Amidate-Functionalized N-Heterocyclic Carbene -Supported Rare-Earth Metal Complexes as Catalysts for Efficient Hydroboration of Unactivated Imines and Nitriles

Well-Defined Amidate-Functionalized N-Heterocyclic Carbene -Supported Rare-Earth Metal Complexes as Catalysts for Efficient Hydroboration of Unactivated Imines and Nitriles

Rare-Earth-Metal-Complex-Catalyzed Hydroalkoxylation and Tandem Hydroalkoxylation/Cyclohydroamination of Isocyanates: Synthesis of Carbamates and Oxazolidinones

Luminescence of Lanthanide Complexes with Perfluorinated Alkoxide Ligands

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