Catexel Ltd

Leiden, Netherlands

Catexel Ltd

Leiden, Netherlands
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The present invention provides improved processes for the synthesis of 1,4-ditosyl-1,4,7-triazacyclonone and protected analogues thereof, and to synthesise bis(triazacyclononane) ligands.


Draksharapu A.,University of Groningen | Angelone D.,University of Groningen | Quesne M.G.,University of Manchester | Padamati S.K.,University of Groningen | And 6 more authors.
Angewandte Chemie - International Edition | Year: 2015

FeIII-hypohalite complexes have been implicated in a wide range of important enzyme-catalyzed halogenation reactions including the biosynthesis of natural products and antibiotics and post-translational modification of proteins. The absence of spectroscopic data on such species precludes their identification. Herein, we report the generation and spectroscopic characterization of nonheme FeIII-hypohalite intermediates of possible relevance to iron halogenases. We show that FeIII-OCl polypyridylamine complexes can be sufficiently stable at room temperature to be characterized by UV/Vis absorption, resonance Raman and EPR spectroscopies, and cryo-ESIMS. DFT methods rationalize the pathways to the formation of the FeIII-OCl, and ultimately FeIV=O, species and provide indirect evidence for a short-lived FeII-OCl intermediate. The species observed and the pathways involved offer insight into and, importantly, a spectroscopic database for the investigation of iron halogenases. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Patent
CATEXEL Ltd | Date: 2011-09-05

The present invention provides for the optimisation of conditions for treating pulp with a catalyst and hydrogen peroxide to produce a Freeness value (SR) in a web produced from the treated pulp such that the energy required in mechanical agitation of the pulp is reduced.


Patent
CATEXEL Ltd | Date: 2011-07-21

A one-pot method for the oxidative cleavage of unsaturated carbon-carbon bonds to provide a carboxylic acid or a ketone-containing compound is disclosed. The method comprises contacting an alkene or an alkyne with hydrogen peroxide and a manganese transition metal catalyst having a ligand of formula (I): wherein: and p is 3.


Patent
CATEXEL Ltd | Date: 2011-05-09

The present invention provides for the optimisation of conditions for treating pulp with a catalyst and hydrogen peroxide to produce a Freeness value (SR) in a web produced from the treated pulp such that the energy required in mechanical agitation of the pulp is reduced.


Patent
CATEXEL Ltd | Date: 2010-03-03

The present invention concerns synthesising manganese complexes in essentially non-aqueous solutions.


Patent
Catexel Ltd | Date: 2015-01-30

The present invention relates to an oxidatively curable coating composition with which a formulation for use in catalysing the curing of oxidatively curable coating compositions, in particular oxidatively curable coating compositions comprising an oxidatively curable alkyd-based resin, has been contacted. The formulations described herein comprise a triazacyclononane-based chelant; a manganese (II), (III) or (IV) salt; and an alcohol or ketone, which alcohol or ketone typically acts as a solvent for the salt and the chelant. The invention also relates to preparing the oxidatively curable coating compositions of the invention, such coating compositions once cured and methods comprising applying such coating compositions to a substrate.


Patent
CATEXEL Ltd | Date: 2011-04-15

The present invention concerns the treatment of substrates with a preformed transition metal catalyst in an aqueous solution. The transitional metal catalyst is a dinuclear Mn transitional metal catalyst and its ligand has the following formula (I): and p is 3.


Patent
Catexel Ltd | Date: 2015-08-06

The present invention relates to an oxidatively curable coating formulation comprising an oxidatively curable alkyd-based resin and a diazacycloalkane-based chelant, which chelant may optionally be complexed with a suitable transition metal ion. The formulations may be paints or other oxidatively curable coating compositions. The invention also provides methods for making such formulations and compositions resultant from the curing of such formulations.


The present invention provides improved processes for the synthesis of 1,4-ditosyl-1,4,7-triazacyclonone and protected analogues thereof, and to synthesise bis(triazacyclononane) ligands.

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