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. 2019 Jun 4:7:394.
doi: 10.3389/fchem.2019.00394. eCollection 2019.

Synthesis and Structures of Ruthenium Carbonyl Complexes Bearing Pyridine-Alkoxide Ligands and Their Catalytic Activity in Alcohol Oxidation

Xinlong Yan  1 , Xiaohui Yue  1 , Kang Liu  1 , Zhiqiang Hao  1 , Zhangang Han  1 , Jin Lin  1
Affiliations

Synthesis and Structures of Ruthenium Carbonyl Complexes Bearing Pyridine-Alkoxide Ligands and Their Catalytic Activity in Alcohol Oxidation

Xinlong Yan et al. Front Chem. .

Abstract

Reaction of Ru3(CO)12 with two equiv of 6-bromopyridine alcohols 6-bromopyCHROH [(R = C6H5 (L1); R = 4-CH3C6H4 (L2); R = 4-OMeC6H4 (L3); R = 4-ClC6H4 (L4); (R = 4-CF3C6H4 (L5); R = 2-OMeC6H4 (L6); R = 2-CF3C6H4 (L7)] and 6-bromopyC(Me)2OH (L8) in refluxing xylene afforded novel trinuclear ruthenium complexes [6-bromopyCHRO]2Ru3(CO)8 (1a-1g) and [6-bromopyC(Me)2O]2Ru3(CO)8 (1h). These complexes were characterized by FT-IR and NMR spectroscopy as well as elemental analysis. The structures of all the complexes were further confirmed by X-ray crystallographic analysis. In the presence of tert-butyl hydroperoxide (TBHP) as the source of oxidant, complexes 1a-1h displayed high catalytic activities for oxidation of primary and secondary alcohols and most of oxidation reactions could be completed within 1 h at room temperature.

Keywords: alcohols oxidation; chemoselectivity; pyridine alcohols; ruthenium carbonyl complexes; t-butyl hydroperoxide.

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Figures

Scheme 1
Scheme 1
Synthetic routes of Ru complexes.
Figure 1
Figure 1
Perspective view of 1a with thermal ellipsoids are drawn at the 30% probability level. Hydrogens have been omitted for clarity. The selected bond lengths (Å) and angles (°): Ru(1)-Ru(3) 2.7743(10), Ru(2)-Ru(3) 2.7625(10), Ru(1)-O(1) 2.140(5), Ru(2)-O(1) 2.084(6), Ru(1)-N(2) 2.237(7), Ru(2)-N(1) 2.252(7); N(2)-Ru(1)-Ru(3) 157.9(2), N(2)-Ru(1)-Ru(2) 102.2(2), Ru(2)-O(1)-Ru(1) 91.4(2), Ru(1)-O(2)-Ru(2) 91.1(2), Ru(2)-Ru(3)-Ru(1) 66.20(3).
Figure 2
Figure 2
Perspective view of 1c with thermal ellipsoids are drawn at the 30% probability level. Hydrogens and solvent have been omitted for clarity. The selected bond lengths (Å) and angles (°): Ru(1)-O(1) 2.083(3), Ru(2)-O(1) 2.132(3), Ru(1)-Ru(3) 2.7649(5), Ru(2)-Ru(3) 2.7552(6), Ru(1)-N(1) 2.258(4), Ru(2)-N(2) 2.240(4); Ru(1)-O(1)-Ru(2) 92.33(12), Ru(2)-O(3)-Ru(1) 92.00(12), N(1)-Ru(1)-Ru(3) 157.10(10), N(2)-Ru(2)-Ru(3) 157.01(12), Ru(2)-Ru(3)-Ru(1) 66.848(15).
Figure 3
Figure 3
Perspective view of 1g with thermal ellipsoids are drawn at the 30% probability level. Hydrogens have been omitted for clarity. The selected bond lengths (Å) and angles (°): Ru(1)-O(1) 2.089(4), Ru(1)-O(1i) 2.147(4), Ru(1)-N(1) 2.313(5), Ru(2)-Ru(1) 2.7560(7), Ru(2)-Ru(1i) 2.7560(7), Ru(1)-O(1)-Ru(1i) 92.06(15), N(1)-Ru(1)-Ru(1i) 97.72(13), Ru(1)-Ru(2)-Ru(1i) 67.17(2).
Figure 4
Figure 4
Influence of the reaction time on catalytic performance of complex 1a (1-phenylethanol 1.0 mmol, complex 1a 0.5 mol%, TBHP 2.5 mmol, CH3CN 2.0 mL).
Scheme 2
Scheme 2
Proposed mechanism for alcohol oxidation catalyzed by Ru/TBHP system.
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References

    1. Allen S. E., Walvoord R. R., Padilla-Salinas R., Kozlowski M. C. (2013). Aerobic copper-catalyzed organic reactions. Chem. Rev. 113, 6234–6458. 10.1021/cr300527g - DOI - PMC - PubMed
    1. Annunziata A., Esposito R., Gatto G., Cucciolito M. E., Tuzi A., Macchioni A., et al. (2018). Iron (III) complexes with cross-bridged cyclams: synthesis and use in alcohol and water oxidation catalysis. Eur. J. Inorg. Chem. 2018, 3304–3311. 10.1002/ejic.201800451 - DOI
    1. Balaraman E., Khaskin E., Leitus G., Milstein D. (2013). Catalytic transformation of alcohols to carboxylic acid salts and H2 using water as the oxygen atom source. Nat. Chem. 5, 122–125. 10.1038/nchem.1536 - DOI - PubMed
    1. Bianchini C., Shen P. K. (2009). Palladium-based electrocatalysts for alcohol oxidation in half cells and in direct alcohol fuel cells. Chem. Rev. 109, 4183–4206. 10.1021/cr9000995 - DOI - PubMed
    1. Borah B. J., Mahanta A., Mondal M., Gogoi H., Yamada Y., Bharali P. (2018). Cobalt-copper nanoparticles catalyzed selective oxidation reactions: efficient catalysis at room temperature. Chem. Select 3, 9826–9832. 10.1002/slct.201801140 - DOI

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