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Heydari N, Bikas R, Shaterian M, Lis T. Green solvent free epoxidation of olefins by a heterogenised hydrazone-dioxidotungsten(vi) coordination compound. RSC Adv 2022; 12:4813-4827. [PMID: 35425511 PMCID: PMC8981271 DOI: 10.1039/d1ra09217k] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 01/27/2022] [Indexed: 12/19/2022] Open
Abstract
A new mononuclear tungsten coordination compound, [WO2L(CH3OH)] (1), was synthesized by the reaction of WCl6 and H2L (H2L = (E)-4-amino-N'-(5-bromo-2-hydroxybenzylidene)benzohydrazide) in methanol. Both the H2L and compound 1 were characterized by elemental analysis and UV-Vis, FT-IR and NMR spectroscopic methods. The molecular structure of compound 1 was also determined by single crystal X-ray analysis which confirmed the compound is a mononuclear coordination compound of cis-dioxidotungsten(vi) containing a free amine functionality on the ligand. Compound 1 was supported on propionyl chloride-functionalized silica gel by amidification reaction to obtain a heterogeneous catalyst. The obtained heterogeneous catalyst was characterized by FT-IR spectroscopy, thermal gravimetric analysis (TGA), diffuse-reflectance spectroscopy (DRS), X-ray diffraction analysis (XRD), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) and its catalytic activity was investigated in the epoxidation of olefins with hydrogen peroxide under solvent free conditions. The catalyst was successfully recovered several times and the recovered catalyst was also characterized by various methods including FT-IR, DRS, TGA, SEM and EDX analyses. The results indicated this heterogeneous catalytic system is an effective and selective catalyst for epoxidation of olefins and can be reused several times without significant change in its catalytic activity.
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Affiliation(s)
- Neda Heydari
- Department of Chemistry, Faculty of Science, University of Zanjan 45371-38791 Zanjan Iran
| | - Rahman Bikas
- Department of Chemistry, Faculty of Science, Imam Khomeini International University 34148-96818 Qazvin Iran
| | - Maryam Shaterian
- Department of Chemistry, Faculty of Science, University of Zanjan 45371-38791 Zanjan Iran
| | - Tadeusz Lis
- Faculty of Chemistry, University of Wroclaw Joliot-Curie 14 Wroclaw 50-383 Poland
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Sampani SI, Zdorichenko V, Devonport J, Rossini G, Leech MC, Lam K, Cox B, Abdul-Sada A, Vargas A, Kostakis GE. Structural and Electronic Control of the Bidentate 1-(2-pyridyl)benzotriazole Ligand in Copper Chemistry with Application to Catalysis in the A 3 Coupling Reaction. Chemistry 2021; 27:4394-4400. [PMID: 33296102 DOI: 10.1002/chem.202004781] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 12/08/2020] [Indexed: 12/15/2022]
Abstract
The hybrid bidentate 1-(2-pyridyl)benzotriazole (pyb) ligand was introduced into 3d transition metal catalysis. Specifically, [CuII (OTf)2 (pyb)2 ]⋅2 CH3 CN (1) enables the synthesis of a wide range of propargylamines by the A3 coupling reaction at room temperature in the absence of additives. Experimental and high-level theoretical calculations suggest that the bridging N atom of the ligand imposes exclusive trans coordination at Cu and allows ligand rotation, while the N atom of the pyridine group modulates charge distribution and flux, and thus orchestrates structural and electronic precatalyst control permitting alkyne binding with simultaneous activation of the C-H bond via a transient CuI species.
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Affiliation(s)
- Stavroula I Sampani
- Department of Chemistry, School of Life Sciences, University of Sussex, Brighton, BN1 9QJ, UK
| | - Victor Zdorichenko
- Photodiversity Ltd. c/o Department of Chemistry, School of Life Sciences, University of Sussex, Brighton, BN1 9QJ, UK
| | - Jack Devonport
- Department of Chemistry, School of Life Sciences, University of Sussex, Brighton, BN1 9QJ, UK
| | - Gioia Rossini
- Department of Chemistry, School of Life Sciences, University of Sussex, Brighton, BN1 9QJ, UK
| | - Matthew C Leech
- School of Science, Department of Pharmaceutical Chemical and Environmental Sciences, University of Greenwich, Central Avenue, Chatham Maritime, ME4 4TB, UK
| | - Kevin Lam
- School of Science, Department of Pharmaceutical Chemical and Environmental Sciences, University of Greenwich, Central Avenue, Chatham Maritime, ME4 4TB, UK
| | - Brian Cox
- Department of Chemistry, School of Life Sciences, University of Sussex, Brighton, BN1 9QJ, UK.,Photodiversity Ltd. c/o Department of Chemistry, School of Life Sciences, University of Sussex, Brighton, BN1 9QJ, UK
| | - Alaa Abdul-Sada
- Department of Chemistry, School of Life Sciences, University of Sussex, Brighton, BN1 9QJ, UK
| | - Alfredo Vargas
- Department of Chemistry, School of Life Sciences, University of Sussex, Brighton, BN1 9QJ, UK
| | - George E Kostakis
- Department of Chemistry, School of Life Sciences, University of Sussex, Brighton, BN1 9QJ, UK
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Schachner JA, Belaj F, Mösch-Zanetti NC. Isomers in chlorido and alkoxido-substituted oxidorhenium(v) complexes: effects on catalytic epoxidation activity. Dalton Trans 2020; 49:11142-11149. [PMID: 32743619 DOI: 10.1039/d0dt02352c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The syntheses and characterizations of oxidorhenium(v) complexes trans-dichlorido [ReOCl2(PPh3)(L1a)] (trans-2a), cis-dichlorido [ReOCl2(PPh3)(L1b)] (cis-2b) and ethoxido-complex [ReO(OEt)(L1b)2] (4b), ligated with the dimethyloxazoline-phenol ligands HL1a and HL1b are described. The bidentate ligand HL1a (2-(4,4-dimethyl-4,5-dihydro-1,3-oxazol-2-yl)-phenol) is unsubstituted on the phenol ring; ligand HL1b (2-(4,4-dimethyl-4,5-dihydro-1,3-oxazol-2-yl)-4-nitrophenol) contains a nitro group in para-position to the hydroxy group. In the reaction of precursor complex [ReOCl3(PPh3)2] and HL1a the two stereoisomers cis/trans-2a, with respect to chlorido ligands, are formed. The solid state structures of both isomers cis- and trans-2a were determined by single crystal X-ray diffraction analysis. In contrast, with ligand HL1b, only the cis-isomer cis-2b was obtained. Ethoxido-complex 4b is exclusively obtained when precursor [ReOCl3(OPPh3)(SMe2)] is reacted with 2 equiv. of HL1b in ethanol in the presence of the base 2,6-dimethylpyridine (lutidine). If no lutidine is added, chlorido-complex [ReOCl(L1b)2] (3b) is obtained. Complexes [ReOCl2(PPh3)(L1a)] (cis/trans-2a), [ReOCl2(PPh3)(L1b)] (cis-2b), [ReO(OMe)(L1a)2] (4a) and [ReO(OEt)(L1b)2] (4b) were tested as homogeneous catalysts in the benchmark reaction of cyclooctene epoxidation. The influence of isomerism and effects of ligand substitutions on catalytic activity was investigated. Based on the time-conversion plots it can be concluded that cis/trans-isomerism does not influence catalytic activity, but electron-withdrawing substituents, as in cis-2b, 3b and 4b, show a beneficial effect.
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Affiliation(s)
- Jörg A Schachner
- Institute of Chemistry, Inorganic Chemistry, University of Graz, Schubertstr. 1, 8010 Graz, Austria.
| | - Ferdinand Belaj
- Institute of Chemistry, Inorganic Chemistry, University of Graz, Schubertstr. 1, 8010 Graz, Austria.
| | - Nadia C Mösch-Zanetti
- Institute of Chemistry, Inorganic Chemistry, University of Graz, Schubertstr. 1, 8010 Graz, Austria.
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