MECHANISM OF BIOMIMETIC OXIDATION OF CYCLOHEXANE TO CYCLOHEXANONE BY HYDROGEN PEROXIDE

The process of gas-phase oxidation of cyclohexane was studied in the presence of a heterogeneous biomimetic catalyst (per-FTPhPFe(III)OH/Al2O3), at 130–2500C, in which high yields of cyclohexanone and cyclohexanol were obtained up to 25.2% with a selectivity of ~80% at a cyclohexane conversion of 34%. The mechanism of the conversion of cyclohexane to cyclohexanone has been studied in detail, and the coherently synchronized character of the reaction proceeding is shown

Biomimetic caged platinum catalyst for hydrosilylation reaction with high site selectivity

Natural enzymes exhibit unparalleled selectivity due to the microenvironment around the active sites, but how to design artificial catalysts to achieve similar performance is a formidable challenge for the catalysis community. Herein, we report that a less selective platinum catalyst becomes highly active and selective for industrially relevant hydrosilylation of a broad range of substrates when a porous cage ligand is used for confinement around the catalytic active site. The catalyst is more than ten times more active than Karstedt’s catalyst while being recyclable. Properties such as size-selective catalysis and Michaelis-Menten kinetics support the proposed enzyme-like model. This biomimetic catalyst exhibits remarkable site-selectivity through the cage’s confining effect, which amplifies small steric differences into dramatic reactivity changes for similar functional groups within a molecule.

Biomimetic Catalysts of Iron–based Metal-Organic Frameworks with High Peroxidase-Mimicking Activity for Colorimetric Biosensing

The field of Metal-Organic Frameworks (MOFs)-based biomimetic catalyst has achieved great progresses, but is still in its infancy stage. The systematic investigation on the tailored construction of MOF-based biomimetic catalysts...

Effects of Polycyclic Aromatic Hydrocarbon Pendant-Armed Ligands on the Catecholase Activity of Dinuclear Copper(II) Complexes

Herein, we present three new binuclear copper(II) complexes containing different polycyclic aromatic hydrocarbons, able to catalyze the oxidation of 3,5-di-tert-butylcathecol, a model substrate for catechol oxidase. The ligands and complexes were successful characterized in solid and solution states. The structure of C1 was determined by X-ray crystallography and it contains a [CuII2(L1-μ-phenoxo)(OAc)(H2O)2] unit, with two coppers in a pyramidal square geometry and a large distance of 3.715 Å between the copper(II) centers. All complexes (C1, C2 and C3) were found to be effective catalysts in the oxidation of 3,5-di-tert-butylcathecol to its quinone and C1 provided the highest catalytic constants at the three pH values studied. In addition to their potential use as a biomimetic catalyst in catechol oxidation, the interaction of these complexes with deoxyribonucleic acid from calf thymus (CT-DNA) was also studied, and C3 showed the greatest affinity with nucleic acids.

Bis(2,2′-bipyridil)Copper(II) Chloride Complex: Tyrosinase Biomimetic Catalyst or Redox Mediator?

In this article, construction of amperometric sensor(s) based on screen-printed carbon electrodes covered by thin layers of two types of carbon nanomaterials serving as amplifiers, and containing [Cu(bipy)2Cl]Cl∙5H2O complex is reported. Their performance and biomimetic activity towards two selected neurotransmitters (dopamine and serotonin) was studied mainly using flow injection analysis (FIA). The important parameters of FIA such as working potential, flow rate, and pH were optimized. The mechanism of the catalytic activity is explained and experimentally confirmed. It reveals that presence of hydrogen peroxide plays a crucial role which leads to answer the title question: can presented complex really be considered as a tyrosinase biomimetic catalyst or only as a redox mediator?

Supramolecular Catalysis: an Efficient and Sustainable Multicomponent Approach to the Synthesis of Novel Hexahydro-4H- indazol-4-one Derivatives

: We have developed an efficient, novel one-pot multicomponent protocol for the synthesis of hexahydro-4H-indazol-4-one derivatives using -cyclodextrin as a biomimetic catalyst in aqueous medium. To the best of our knowledge, the targeted molecules have not been reported in the literature until now. The present method is very effective for our densely functionalized and diversified targeted molecules and includes several advantages like environment benign, cost effectiveness, short reaction times, high yields and recyclability of catalyst.

Merrifield resin-supported quinone as an efficient biomimetic catalyst for metal-free, base-free, chemoselective synthesis of 2,4,6-trisubstituted pyridines

Metal-free, base-free, biomimetic, and chemoselective synthesis of 2,4,6-trisubstituted pyridines was developed for the first time under mild conditions.