- Potentiometric and AM1d studies of the equilibria between silver(I) and diaza-15-crown and diaza-18-crown ethers with nitrogen in different positions in various solvents
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Complex formation and stability constants between typical and atypical diaza-15-crown and diaza-18-crown ethers with silver(I) were determined in methanol, acetonitrile and propylene carbonate by the potentiometric method. In two of the diaza crown ethers, AA-diaza-15 and AA-diaza-18-crown, two nitrogens in the macrocyclic ring replaced two consecutive oxygens instead of two opposite ones in the two other diaza crown ethers. It was found that complexes of 1:1 and 1:2 metal-to-ligand stoichiometry were formed. The solvent composition and cavity size of crown ethers significantly influences the stability constants of complexes. AA-diaza-15 and AA-diaza-18-crown ethers were examined for comparison with diaza-15-crown and diaza-18-crown ethers. AA-diaza crown ethers formed less stable 1:1 metal-to-ligand complexes with silver(I) than typical diaza crown ethers but their ability to form 1:2 metal-to-ligand complexes was stronger. The energetically most favorable structures of the 1:1 metal-to-ligand complexes were calculated and visualized by the AM1d method at the semiempirical level of theory.
- Kira, Jaromir,Niedzialkowski, Pawel,Ossowski, Tadeusz
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- Low-Temperature Reductive Aminolysis of Carbohydrates to Diamines and Aminoalcohols by Heterogeneous Catalysis
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Short amines, such as ethanolamines and ethylenediamines, are important compounds in today's bulk and fine chemicals industry. Unfortunately, current industrial manufacture of these chemicals relies on fossil resources and requires rigorous safety measures when handling explosive or toxic intermediates. Inspired by the elegant working mechanism of aldolase enzymes, a novel heterogeneously catalyzed process—reductive aminolysis—was developed for the efficient production of short amines from carbohydrates at low temperature. High-value bio-based amines containing a bio-derived C2 carbon backbone were synthesized in one step with yields up to 87 C%, in the absence of a solvent and at a temperature below 405 K. A wide variety of available primary and secondary alkyl- and alkanolamines can be reacted with the carbohydrate to form the corresponding C2-diamine. The presented reductive aminolysis is therefore a promising strategy for sustainable synthesis of short, acyclic, bio-based amines.
- Pelckmans, Michiel,Vermandel, Walter,Van Waes, Frederik,Moonen, Kristof,Sels, Bert F.
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p. 14540 - 14544
(2017/10/23)
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- PROCESS FOR PREPARING EDFA AND/OR EDMFA AND DETA AND/OR TETA
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A process for reacting ethylenediamine (EDA) with formaldehyde to give ethylenediamine-formaldehyde adduct (EDFA) and/or ethylenediamine-monoformaldehyde adduct (EDMFA), which comprises performing the reaction of FA with EDA at a temperature in the range from 20 to 70° C.
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Paragraph 0486; 0489
(2013/03/26)
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- PROCESS FOR PREPARING EDDN AND/OR EDMN AND PROCESS FOR PREPARING DETA AND/OR TETA
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A process for preparing EDDN and/or EDMN by conversion of FA, HCN and EDA, the reaction being effected in the presence of water, wherein the reaction mixture from the conversion of EDA, HCN and FA is cooled after leaving the reactor.
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Paragraph 0574
(2013/03/26)
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- Ceramide-like compounds and a method for preparation thereof, and a cosmetic composition containing the same
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Disclosed herein is a ceramide-like compound having properties of the natural ceramides, and a method for producing the same, and a cosmetic composition containing the same as a active ingredient.
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- Method and apparatus for sunless tanning
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Apparatus for simulating skin tanning comprises a receptacle containing a fluid comprising dihydroxyacetone, a receptacle containing a fluid comprising a secondary polyamine, and dispensing means for simultaneously or sequentially providing desired amounts of dihydroxyacetone and polyamine.
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- SYNTHESIS OF N-UNSUBSTITUTED DI- AND TRIAZA CROWN ETHERS.
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Facile syntheses of di- and triaza crown ethers by intramolecular cyclization of oligoethylene glycols containing two or three imino groups or by their intermolecular cyclization with oligoethylene glycol bis(p-toluenesulfonate)s are described.
- Maeda,Furuyoshi,Nakatsuji,Okahara
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p. 3073 - 3077
(2007/10/02)
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- Hydroformylation of olefins using azoxy-dentated ligands
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At a temperature in the range 100° C to 225° C the destructive dissociation of cobalt carbonyl compounds to cobalt metal and residue is inhibited by the action of one or more azoxy-dentated chelation ligands.
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- Process for preparing nitrogen-containing heterocyclic compounds
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Nitrogen-containing heterocyclic compounds are prepared by cyclization of a compound having the formula: EQU1 or EQU2 wherein X represents a hydrogen atom or --CH2 CHR-Y; R represents a hydrogen atom or methyl atom; Y represents an --OH group or --NH2 group; and n represents the integers 0 or 1 - 4; with a zeolite catalyst having the formula wherein M represents a cation selected from alkali metals, alkaline earth metals, zinc group elements, hydrogen and ammonium cations; n represents the valence of the cation; a is 1.0 ± 0.5 and m is 2 - 12.
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