AUTHOR=Yan Xinlong , Yue Xiaohui , Liu Kang , Hao Zhiqiang , Han Zhangang , Lin Jin 

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

JOURNAL=Frontiers in Chemistry

VOLUME=7

YEAR=2019

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2019.00394

DOI=10.3389/fchem.2019.00394

ISSN=2296-2646

ABSTRACT=<p>Reaction of Ru<sub>3</sub>(CO)<sub>12</sub> with two equiv of 6-bromopyridine alcohols 6-bromopyCHROH [(R = C<sub>6</sub>H<sub>5</sub> (<bold>L1</bold>); R = 4-CH<sub>3</sub>C<sub>6</sub>H<sub>4</sub> (<bold>L2</bold>); R = 4-OMeC<sub>6</sub>H<sub>4</sub> (<bold>L3</bold>); R = 4-ClC<sub>6</sub>H<sub>4</sub> (<bold>L4</bold>); (R = 4-CF<sub>3</sub>C<sub>6</sub>H<sub>4</sub> (<bold>L5</bold>); R = 2-OMeC<sub>6</sub>H<sub>4</sub> (<bold>L6</bold>); R = 2-CF<sub>3</sub>C<sub>6</sub>H<sub>4</sub> (<bold>L7</bold>)] and 6-bromopyC(Me)<sub>2</sub>OH (<bold>L8</bold>) in refluxing xylene afforded novel trinuclear ruthenium complexes [6-bromopyCHRO]<sub>2</sub>Ru<sub>3</sub>(CO)<sub>8</sub> (<bold>1a-1g</bold>) and [6-bromopyC(Me)<sub>2</sub>O]<sub>2</sub>Ru<sub>3</sub>(CO)<sub>8</sub> (<bold>1h</bold>). 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 <italic>tert</italic>-butyl hydroperoxide (TBHP) as the source of oxidant, complexes <bold>1a</bold>-<bold>1h</bold> 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.</p>