Rh-Catalyzed Reductive Amination of Undecanal in an Aqueous Microemulsion System Using a Non-Ionic Surfactant

The homogeneously catalyzed reductive amination of the long-chain aldehyde undecanal with diethylamine was performed in an aqueous microemulsion system using the non-ionic surfactant Marlophen NP8. The experiments showed that the used water-soluble rhodium/SulfoXantphos catalyst system is suitable for this reaction. The Rh-catalyzed formation of the alcohol by-product can be completely suppressed by the use of carbon monoxide with its stabilizing effect of the catalyst system. In addition to pressure and temperature, the most important parameters for the reaction performance of the reductive amination are the concentrations of reactants. Especially, the initial concentration of the aldehyde has a strong impact on the chemoselectivity, and the formation of aldol by-product due to the fact that both, the enamine condensation and the aldol condensation are equilibrium reactions.

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Aqueous reductive amination using a dendritic metal catalyst in a dialysis bag

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.9.110 ◽

2013 ◽

Vol 9 ◽

pp. 960-965 ◽

Cited By ~ 2

Author(s):

Jorgen S Willemsen ◽

Jan C M van Hest ◽

Floris P J T Rutjes

Keyword(s):

Reductive Amination ◽

Reaction Times ◽

Catalyst System ◽

Water Soluble ◽

Metal Catalyst ◽

Complex Reaction ◽

Reactive Metal ◽

Iridium Catalysts ◽

Equilibrium Reactions ◽

Dialysis Bag

Water-soluble dendritic iridium catalysts were synthesized by attaching a reactive metal complex to DAB-Am dendrimers via an adapted asymmetric bipyridine ligand. These dendritic catalysts were applied in the aqueous reductive amination of valine while contained in a dialysis bag. Comparable conversions were observed as for the noncompartmentalized counterparts, albeit with somewhat longer reaction times. These results clearly show that the encapsulated catalyst system is suitable to successfully drive a complex reaction mixture with various equilibrium reactions to completion.

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Characterization of Chemical Impurities in Glutaraldehyde

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100116723 ◽

1975 ◽

Vol 33 ◽

pp. 620-621

Author(s):

B. J. Grenon ◽

A. J. Tousimis

Keyword(s):

Glutaric Acid ◽

Spectroscopic Analysis ◽

Aldol Condensation ◽

Condensation Product ◽

Amorphous Solid ◽

Water Soluble ◽

Impurity Component ◽

Chemical Impurities ◽

Soluble Liquid

Ever since the introduction of glutaraldehyde as a fixative in electron microscopy of biological specimens, the identification of impurities and consequently their effects on biologic ultrastructure have been under investigation. Several reports postulate that the impurities of glutaraldehyde, used as a fixative, are glutaric acid, glutaraldehyde polymer, acrolein and glutaraldoxime.Analysis of commercially available biological or technical grade glutaraldehyde revealed two major impurity components, none of which has been reported. The first compound is a colorless, water-soluble liquid with a boiling point of 42°C at 16 mm. Utilizing Nuclear Magnetic Resonance (NMR) spectroscopic analysis, this compound has been identified to be — dihydro-2-ethoxy 2H-pyran. This impurity component of the glutaraldehyde biological or technical grades has an UV absorption peak at 235nm. The second compound is a white amorphous solid which is insoluble in water and has a melting point of 80-82°C. Initial chemical analysis indicates that this compound is an aldol condensation product(s) of glutaraldehyde.

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Optimizing Chitin Depolymerization by Lysozyme to Long-Chain Oligosaccharides

Marine Drugs ◽

10.3390/md19060320 ◽

2021 ◽

Vol 19 (6) ◽

pp. 320

Author(s):

Arnaud Masselin ◽

Antoine Rousseau ◽

Stéphanie Pradeau ◽

Laure Fort ◽

Rodolphe Gueret ◽

...

Keyword(s):

Time Course ◽

Water Soluble ◽

Organic Fertilizers ◽

Symbiotic Associations ◽

Egg White Lysozyme ◽

Hen Egg White ◽

Ecological Transition ◽

Optimized Conditions ◽

Hydrolysis Of ◽

Long Chain

Chitin oligosaccharides (COs) hold high promise as organic fertilizers in the ongoing agro-ecological transition. Short- and long-chain COs can contribute to the establishment of symbiotic associations between plants and microorganisms, facilitating the uptake of soil nutrients by host plants. Long-chain COs trigger plant innate immunity. A fine investigation of these different signaling pathways requires improving the access to high-purity COs. Here, we used the response surface methodology to optimize the production of COs by enzymatic hydrolysis of water-soluble chitin (WSC) with hen egg-white lysozyme. The influence of WSC concentration, its acetylation degree, and the reaction time course were modelled using a Box–Behnken design. Under optimized conditions, water-soluble COs up to the nonasaccharide were formed in 51% yield and purified to homogeneity. This straightforward approach opens new avenues to determine the complex roles of COs in plants.

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Transformation of Construction Cement to a Self-Healing Hybrid Binder

International Journal of Molecular Sciences ◽

10.3390/ijms20122948 ◽

2019 ◽

Vol 20 (12) ◽

pp. 2948 ◽

Cited By ~ 2

Author(s):

Werner E.G. Müller ◽

Emad Tolba ◽

Shunfeng Wang ◽

Qiang Li ◽

Meik Neufurth ◽

...

Keyword(s):

Soil Bacteria ◽

Construction Material ◽

Water Soluble ◽

The Self ◽

Average Chain Length ◽

Self Healing ◽

Cement Concrete ◽

Low Concentrations ◽

Natural Mechanism ◽

Long Chain

A new biomimetic strategy to im prove the self-healing properties of Portland cement is presented that is based on the application of the biogenic inorganic polymer polyphosphate (polyP), which is used as a cement admixture. The data show that synthetic linear polyp, with an average chain length of 40, as well as natural long-chain polyP isolated from soil bacteria, has the ability to support self-healing of this construction material. Furthermore, polyP, used as a water-soluble Na-salt, is subject to Na+/Ca2+ exchange by the Ca2+ from the cement, resulting in the formation of a water-rich coacervate when added to the cement surface, especially to the surface of bacteria-containing cement/concrete samples. The addition of polyP in low concentrations (<1% on weight basis for the solids) not only accelerated the hardening of cement/concrete but also the healing of microcracks present in the material. The results suggest that long-chain polyP is a promising additive that increases the self-healing capacity of cement by mimicking a bacteria-mediated natural mechanism.

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Nonaqueous Biphasic Hydroformylation of Long Chain Alkenes Catalyzed by Water Soluble Phosphine Rhodium Catalyst with Polyethylene Glycol Instead of Water

Catalysis Letters ◽

10.1007/s10562-017-2247-6 ◽

2017 ◽

Vol 148 (1) ◽

pp. 438-442 ◽

Cited By ~ 5

Author(s):

Yuanjiang Zhao ◽

Yanli Liu ◽

Jianzhang Wei ◽

Haiyan Fu ◽

Xueli Zheng ◽

...

Keyword(s):

Polyethylene Glycol ◽

Rhodium Catalyst ◽

Water Soluble ◽

Water Soluble Phosphine ◽

Long Chain

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Synthesis of long chain alkanes via aldol condensation over modified chitosan catalyst and subsequent hydrodeoxygenation

Chemical Engineering Journal ◽

10.1016/j.cej.2021.131368 ◽

2021 ◽

pp. 131368

Author(s):

Xuelai Zhao ◽

Song Li ◽

Yuzhen Hu ◽

Xinghua Zhang ◽

Lungang Chen ◽

...

Keyword(s):

Aldol Condensation ◽

Modified Chitosan ◽

Long Chain

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Application of Amino Transaminases in a Disperse System for the Biotransformation of Hydrophobic Substrates

10.26434/chemrxiv.10087331.v1 ◽

2019 ◽

Author(s):

Andrea Fiorati ◽

Per Berglund ◽

maria humble ◽

Davide Tessaro

Keyword(s):

Disperse System ◽

Reductive Amination ◽

Ionic Surfactant ◽

Minimal Amount

The challenging bioamination of hydrophobic substrates has been attained through the employment of a disperse system consisting in a combination of a low polarity solvent (e.g. isooctane or MTBE), a non-ionic surfactant and a minimal amount of water. In these conditions, good conversions are achieved, often coupled with a superior stereoselectivity if compared with the corresponding chemical reductive amination. An array of synthetically useful 4-substituted aminocyclohexanes was consequentially synthesized and stereochemically characterized.<br>

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Water-soluble polyesters from long chain alkylesters of citric acid and poly(ethylene glycol)

European Polymer Journal ◽

10.1016/j.eurpolymj.2007.01.028 ◽

2007 ◽

Vol 43 (4) ◽

pp. 1288-1301 ◽

Cited By ~ 5

Author(s):

Fabienne Barroso-Bujans ◽

Ricardo Martínez ◽

Mehrdad Yazdani-Pedram ◽

Pedro Ortiz ◽

Holger Frey

Keyword(s):

Citric Acid ◽

Ethylene Glycol ◽

Water Soluble ◽

Poly Ethylene Glycol ◽

Poly Ethylene ◽

Long Chain

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A Novel Embed Fluorescence Method for Monitoring the Change from Emulsion Polymeriztion to Microemulsion Polymerization

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.303-306.323 ◽

2013 ◽

Vol 303-306 ◽

pp. 323-328

Author(s):

Hai Ke Feng

Keyword(s):

Anionic Surfactant ◽

Sodium Dodecyl Sulphate ◽

Trace Amount ◽

Sodium Dodecyl ◽

Fluorescence Emission ◽

Fluorescence Method ◽

Water Soluble ◽

Ionic Surfactant ◽

Microemulsion Polymerization ◽

Fluorescence Emission Intensity

In this paper, we present a novel embed fluorescence method that allows one to monitor the change from emulsion polymerization to microemulsion polymerization with low monomer contents. The microemulsion polymerization of methyl methacrylate (MMA) was investigated using N-(2-anthracene) methacrylamide (AnMA) as the probe whose fluorescence emission intensity was proportional to the conversion of MMA into the polymer.In this research, the trace amount of AnMA unit looked like embed in the MMA chain. In a solution containing 3wt% of MMA with respect to water, with the anionic surfactant of sodium dodecyl sulphate (SDS) and water-soluble initiator of potassium persulfate (KPS), the process of changing from emulsion to microemulsion has been monitored. By contrast, with the non-ionic surfactant of polyoxyethylene (20) oleyl ether (Brij98) or water-insoluble initiator of 2,2′-azobis(isobutyronitrile) (AIBN), the process of changing from emulsion to microemulsion also have been monitored.

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