AUTHOR=Ros Dimitri , Gianferrara Teresa , Crotti Corrado , Farnetti Erica 

TITLE=Iron-Catalyzed Oxidation of 1-Phenylethanol and Glycerol With Hydrogen Peroxide in Water Medium: Effect of the Nitrogen Ligand on Catalytic Activity and Selectivity

JOURNAL=Frontiers in Chemistry

VOLUME=8

YEAR=2020

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2020.00810

DOI=10.3389/fchem.2020.00810

ISSN=2296-2646

ABSTRACT=<p>The iron(II) complexes [Fe(bpy)<sub>3</sub>](OTf)<sub>2</sub> (bpy = 2,2'-bipyridine; OTf = CF<sub>3</sub>SO<sub>3</sub>) (<bold>1</bold>) and [Fe(bpydeg)<sub>3</sub>](OTf)<sub>2</sub> (bpydeg = <italic>N</italic><sup>4</sup>,<italic>N</italic><sup>4</sup>-bis(2-(2-methoxyethoxy)ethyl) [2,2'-bipyridine]-4,4'-dicarboxamide) (<bold>2</bold>), the latter being a newly synthesized ligand, were employed as catalyst precursors for the oxidation of 1-phenylethanol with hydrogen peroxide in water, using either microwave or conventional heating. With the same oxidant and medium the oxidation of glycerol was also explored in the presence of <bold>1</bold> and <bold>2</bold>, as well as of two similar iron(II) complexes bearing tridentate ligands, <italic>i.e</italic>., [Fe(terpy)<sub>2</sub>](OTf)<sub>2</sub> (terpy = 2, 6-di(2-pyridyl)pyridine<bold>)</bold> (<bold>3</bold>) and [Fe(bpa)<sub>2</sub>](OTf)<sub>2</sub> (bpa = bis(2-pyridinylmethyl)amine) (<bold>4</bold>): in most reactions the major product formed was formic acid, although with careful tuning of the experimental conditions significant amounts of dihydroxyacetone were obtained. Addition of heterocyclic amino acids (<italic>e.g.</italic>, picolinic acid) increased the reaction yields of most catalytic reactions. The effect of such additives on the evolution of the catalyst precursors was studied by spectroscopic (NMR, UV-visible) and ESI-MS techniques.</p>