Iron complexes with nitrogen bidentate ligands as green catalysts foralcohol oxidation

The iron(II) complexes [Fe(N-N)3](OTf)2(N-N = 2,2- bipyridine, 1,10-phenanthroline and substitutedderivatives) were employed as catalyst precursors for the oxidation of primary and secondary alcohols,including glycerol. The single-crystal structure of [Fe(bipy)3](OTf)2was determined by X-ray crystallog-raphy.The catalytic reactions were performed using either H2O2or tert-butilhydroperoxide (TBHP) asoxidating agent, in mild experimental conditions: with all catalysts employed, secondary alcohols wereoxidized to the corresponding ketones with up to 100% yields, whereas other substrates gave lowerconversions. Indications on the nature of the catalytically active species, which is probably formed viadissociation of a nitrogen ligand from the iron center, were obtained from NMR and ESI\u2013MS spectra

CC chemokine receptor 5 polymorphism in Italian patients with Behcet's disease.

Objective. To evaluate the potential role of CC chemokine receptor 5 (CCR5)Δ32 polymorphism in the susceptibility to and clinical expression of Behçet's disease (BD) in a cohort of Italian patients.Methods. One hundred and ninety-six consecutive Italian patients satisfying the ISG criteria for BD were followed up for 8 years, and 180 healthy age- and sex-matched blood donors were molecularly genotyped for the CCR5Δ32 polymorphism. A standard microlymphocytotoxicity technique was used to serotype HLA-B51. The patients were subgrouped on the basis of the presence or absence of clinical manifestations.Results. The distribution of the CCR5Δ32 genotype differed between BD patients and controls (P = 0.02). The CCR5Δ32 allele was more common in BD patients than in controls [P = 0.02, odds ratio (OR) 2.28 (95% CI 1.1, 4.8)]. Carriers of the CCR5Δ32 allele (Δ32/Δ32 + CCR5/Δ32) were significantly more common in BD patients than in controls [P = 0.02, OR 2.37 (95% CI 1.1, 5.1)]. Population-attributable risk was 7.1%. In categorizing patients according to gender, the association between CCR5Δ32 polymorphism and BD was similar in females and males (ORs 2.76 and 2.0, respectively). No significant differences were found when the frequencies of clinical manifestations were compared between CC5RΔ32 allele carriers and non-carriers.Conclusion. CCR5Δ32 polymorphism is associated with an increased susceptibility to develop BD. Chemokines may have a role in the pathophysiology of BD

Iron complexes with polydentate phosphines as unusual catalysts for alcohol oxidation

The iron(II) compounds [Fe(triphos)(CH3CN)3](OTf)2 (triphos = 1,1,1-tris(diphenylphosphinomethyl)ethane; OTf = CF3SO3) (1), [Fe(dppm)2(CH3CN)2](OTf)2 (dppm = bis(diphenylphosphino)methane) (2), [Fe(dppe)2(CH3CN)2](OTf)2 (dppe = 1,2-bis(diphenylphosphino)ethane) (3), [Fe(dppp)(CH3CN)4](OTf)2 (dppp = 1,3-bis(diphenylphosphino)propane) (4) and [Fe(PSP)(CH3CN)3](OTf)2 (PSP = bis(2-(diphenylphosphino)ethyl)sulfide) (5) were synthesized and characterized by NMR and (2, 3 and 4) also by X-ray crystallography. Such complexes catalyzed the selective oxidation of primary and secondary alcohols to the corresponding aldehydes and ketones. The catalytic reactions were performed in acetonitrile in mild experimental conditions (r.t. or 50 \ub0C) using tert-butylhydroperoxide (TBHP) as oxidizing agent. By following the reaction of complex 4 with the oxidant by UV\u2013visible spectroscopy, it was possible to evidence formation of the corresponding iron-peroxide intermediate. Comparison of ESI-MS spectra acquired on a solution of 1 or 4 before and after TBHP addition suggests ligand oxidation to iron-phosphine oxide complexes

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

The iron(II) complexes [Fe(bpy)3](OTf)2 (bpy = 2,2'-bipyridine; OTf = CF3SO3) (1) and [Fe(bpydeg)3](OTf)2 (bpydeg = N4,N4-bis(2-(2-methoxyethoxy)ethyl) [2,2'-bipyridine]-4,4'-dicarboxamide) (2), 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 1 and 2, as well as of two similar iron(II) complexes bearing tridentate ligands, i.e., [Fe(terpy)2](OTf)2 (terpy = 2, 6-di(2-pyridyl)pyridine) (3) and [Fe(bpa)2](OTf)2 (bpa = bis(2-pyridinylmethyl)amine) (4): 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 (e.g., 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

Chemoselective Hydrogenation Controlled by Steric Effects of Coordinated Phosphines in Iridium Catalysts

Iridium phosphine catalysts for selective reductions

Iridium catalysts for sustainable processes:glycerol dehydrogenation, alkyne polymerization and post-polymerization of polyketones

Applications of iridium catalysts in green chemistr

The Design of a Chemoselective Reduction Catalyst

Design of iridium-based catalyst