Optimization of 2-octanol kinetic resolution by selection of sol-gel immobilization precursors and reaction parameters

2010 ◽  
Vol 150 ◽  
pp. 388-389 ◽  
Author(s):  
A. Ursoiu ◽  
M. Ungurean ◽  
C. Paul ◽  
F. Peter
Keyword(s):  
Kinetic Resolution ◽  
Sol Gel ◽  
Reaction Parameters ◽  
Selection Of

scholarly journals Biocatalytic synthesis of (S)-Practolol, a selective β-blocker

Biocatalysis ◽  
2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Sachin Mulik ◽  
Saptarshi Ghosh ◽  
Jayeeta Bhaumik ◽  
Uttam C. Banerjee
Keyword(s):  
Adrenergic Receptor ◽  
Kinetic Resolution ◽  
Sol Gel ◽  
Enantiomeric Excess ◽  
Green Technology ◽  
Chemoenzymatic Synthesis ◽  
Acyl Donor ◽  
Pseudomonas Cepacia ◽  
Reaction Parameters ◽  
Β Blocker

AbstractThe present study describes an efficient chemoenzymatic synthesis of enantiopure (S)-Practolol, a selective β-adrenergic receptor blocker. Prior to the synthesis of the target, a synthetic protocol for (RS)-N-4-(3-chloro-2-hydroxypropoxy)phenylacetamide, an essential precursor, was developed. Various commercial lipases were screened for the kinetic resolution of (RS)- N-4-(3-chloro-2-hydroxypropoxy)phenylacetamide using toluene as solvent and vinyl acetate as an acyl donor. Among various lipases screened, Pseudomonas cepacia sol-gel AK showed the highest enantioselectivity (96% enantiomeric excess with 50% conversion), affording (S)-1-(4-acetamidophenoxy)-3-chloropropan-2-yl acetate. Optimization of the reaction parameters was carried out in order to find the best-suited conditions for the biocatalysis. Furthermore, the enantiopure intermediate was hydrolyzed and the resulting product was reacted with isopropylamine to afford (S)-Practolol. This biocatalytic procedure depicts a green technology for the synthesis of (S)-Practolol with better yield and enantiomeric excess.

Catalytic Application of H4SiW12O40/SiO2 in Synthesis of Acetals and Ketals

2011 ◽  
Vol 284-286 ◽  
pp. 2374-2379 ◽  
Author(s):  
Shui Jin Yang ◽  
Yong Kui Huang ◽  
Li Yu
Keyword(s):  
Reaction Time ◽  
High Activity ◽  
Sol Gel ◽  
Reaction Parameters ◽  
Reaction Conditions ◽  
Catalytic Application ◽  
Ft Ir ◽  
Gel Technique ◽  
Catalyst Dosage ◽  
Novel Catalyst

A novel catalyst, H4SiW12O40/SiO2was synthesized by a sol-gel technique, and characterized by FT-IR and XRD. Catalytic application of H4SiW12O40/SiO2for synthesis of acetals and ketals were tested. The variation of different reaction parameters, such as mole ratio of aldehyde/ketone to alcohols, catalyst dosage and reaction time on the yield of acetals and ketals were also studied. The results reveal that the H4SiW12O40/SiO2catalysis generally results in good yields of acetals and ketals under mild reaction conditions and the high activity and stability of the catalyst is well retained on recycling.

Influence of Various Reaction Parameters on the Process for Preparation of SiO2/TiO2 Core-Shell Particles

2015 ◽  
Vol 33 ◽  
pp. 27-37 ◽  
Author(s):  
Jhin Hong You ◽  
Yi Yin Kuo ◽  
Keh Ying Hsu
Keyword(s):  
Inorganic Compounds ◽  
Sol Gel ◽  
Chelating Agent ◽  
Condensation Process ◽  
Infrared Analysis ◽  
Ionic Surfactant ◽  
Core Shell ◽  
Reaction Parameters ◽  
The Core ◽  
Shell Particles

This study aims to describe the preparation and characterization of SiO2/TiO2 core-shell particles. In order to prepare the homogenous SiO2/TiO2 inorganic compounds by sol-gel process, SiO2 particles were used as the core, AcAc served as a chelating agent to chelate with TTIP (which was used as the precursor to TiO2), and PEG was added to stabilize the hydrolysis/condensation process. In addition, the ionic surfactant (SDS) and the nonionic surfactant (PVP) dispersed the core-shell particles. In order to improve the crystal structure, a high temperature was used to calcine the core-shell particles. The influence of various reaction parameters on the size, morphology and composition of the particles was also investigated. The properties of the particles were analyzed by electron microscopy, fourier transform infrared analysis, thermogravimetric analysis and powder X-ray diffraction.

scholarly journals Immobilized Whole-Cell Transaminase Biocatalysts for Continuous-Flow Kinetic Resolution of Amines

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 438 ◽  
Author(s):  
Zsófia Molnár ◽  
Emese Farkas ◽  
Ágnes Lakó ◽  
Balázs Erdélyi ◽  
Wolfgang Kroutil ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Kinetic Resolution ◽  
Sol Gel ◽  
Chiral Amines ◽  
Flow Mode ◽  
Immobilized Cell ◽  
Hollow Silica ◽  
E Coli ◽  
Sol Gel Process ◽  
Racemic Amines

Immobilization of transaminases creates promising biocatalysts for production of chiral amines in batch or continuous-flow mode reactions. E. coli cells containing overexpressed transaminases of various selectivities and hollow silica microspheres as supporting agent were immobilized by an improved sol-gel process to produce immobilized transaminase biocatalysts with suitable stability and mechanical properties for continuous-flow applications. The immobilized cell-based transaminase biocatalyst proved to be durable and easy-to-use in kinetic resolution of four racemic amines 1a–d. The batch and continuous-flow mode kinetic resolutions with transaminase biocatalyst of opposite stereopreference provided access to both enantiomers of the corresponding amines. By using the most suitable immobilized transaminase biocatalysts, this study describes the first transaminase-based approach for the production of both pure enantiomers of 1-(3,4-dimethoxyphenyl)ethan-1-amine 1d.

Metrics-Based Sustainability Evaluation of Manufacturing Technologies: Surface Coating Case Study

2009 ◽  
Author(s):  
Q. Z. Yang ◽  
B. H. Chua
Keyword(s):  
Environmental Sustainability ◽  
Sol Gel ◽  
Sustainable Manufacturing ◽  
Powder Coating ◽  
Sustainability Evaluation ◽  
Environmental Evaluation ◽  
Manufacturing Technologies ◽  
Sustainability Assessments ◽  
Selection Of

Sustainability evaluation of manufacturing technologies is a vital part of decision process in sustainable manufacturing, particularly for decisions on transfer/adoption of new sustainable manufacturing innovations. This paper highlights a study on metrics-based sustainability evaluation of technologies in manufacturing, with emphasis on the technical, economical and environmental sustainability assessments. On the basis of three types of sustainability evaluation metrics proposed in this paper, our study integrates technology assessment, cost analysis and environmental evaluation to support decision-making for selection of sustainable manufacturing processes. Case studies about sol-gel coating and powder coating are explored in the paper to test the proposed sustainability evaluation methods and metrics. The assessment results provide quantitative justifications used in technology transfer of the new sol-gel coating innovations. The results also help potential technology adopters to reduce their implementation risks of the sol-gel coating process in automotive decorative applications.

Synthesis of Scandium Oxide Nanoparticles from Solution

2010 ◽  
Vol 62 ◽  
pp. 70-75
Author(s):  
Nathalie Poirot ◽  
Philippe Boy ◽  
Philippe Belleville ◽  
Luc Bianchi
Keyword(s):  
Sol Gel ◽  
Differential Analysis ◽  
X Ray Diffraction ◽  
Time Duration ◽  
Reflux Time ◽  
X Ray ◽  
Transmission Electron ◽  
Strong Relation ◽  
Influence Of Ph ◽  
Selection Of

Scandium oxides nanopowders have been synthesized using a sol-gel route. ScOOH nanoparticles have been first prepared in solution using ScCl3, xH2O as precursor. Influence of pH and reflux time on particles size and shape has been studied. Sc2O3 nanoparticles were then obtained after ScOOH sol drying. Sols were characterized by laser granulometry, thermogravimetry and differential analysis (TGA- DSC). Depending on pH, 40 to 1000 nm size ScOOH particles can be obtained. At a given pH, the reflux time duration also influences the ScOOH particles size. The ScOOH sol can be used to prepare highly pure Sc2O3 nanopowders. X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Transmission Electron Microcopy (TEM), were used to characterize Sc203 nanopowders obtained from the various ScOOH solutions. The DSC and laser granulometry data indicate a strong relation between the nanoparticles size and the temperature of transformation of g-ScOOH to Sc2O3. Depending on the sol preparation various particles Sc2O3 size can then be obtained allowing the selection of the more suitable powder for transparent ceramic preparation.

Influence of reaction parameters on the structure of in situ rubber/silica compounds synthesized via sol-gel reaction

2014 ◽  
Vol 52 (14) ◽  
pp. 967-978 ◽  
Author(s):  
Elena Miloskovska ◽  
Erik Nies ◽  
Denka Hristova-Bogaerds ◽  
Martin van Duin ◽  
Gijsbertus de With
Keyword(s):  
Sol Gel ◽  
Reaction Parameters

Modification of Clinoptilolite by Synthetic Zeolite

1993 ◽  
Vol 58 (8) ◽  
pp. 1782-1790
Author(s):  
Ľubomír Medvecký ◽  
Jaroslav Briančin ◽  
Ján Mihalik
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
Methanol Conversion ◽  
Synthetic Zeolite ◽  
Al Content ◽  
Physico Chemical ◽  
Sol Gel Process ◽  
Dta And Tg ◽  
High Al Content ◽  
Selection Of

The sol-gel process allows to modify clinoptilolite by the nucleation of synthetic zeolite. From the viewpoint of methanol conversion, the obtained high Al content nucleation-deposited zeolite decreases the catalytic activity of clinoptilolite. Therefore, it is necessary to optimize the selection of suitable synthetic zeolite as to its composition. Contamination of zeolite surfaces by carbonaceous fragments during catalytic process results from physico-chemical properties of the used and processed zeolite, and according to DTA and TG analysis it significantly affects the readsorption of water vapours and likely also the zeolite activity in methanol conversion.

scholarly journals Sol–Gel Chemistry of Titanium Alkoxide toward HF: Impacts of Reaction Parameters

2016 ◽  
Vol 16 (9) ◽  
pp. 5441-5447 ◽  
Author(s):  
Wei Li ◽  
Monique Body ◽  
Christophe Legein ◽  
Damien Dambournet
Keyword(s):  
Sol Gel ◽  
Titanium Alkoxide ◽  
Reaction Parameters

Synthesis of Acetals and Ketals Catalyzed by H4SiW6Mo6O40/SiO2

2012 ◽  
Vol 430-432 ◽  
pp. 289-292
Author(s):  
Shui Jin Yang ◽  
Li Yu ◽  
Yong Kui Huang ◽  
Guo Bin Duan
Keyword(s):  
High Activity ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Reusable Catalyst ◽  
Reaction Parameters ◽  
Catalytic Application ◽  
Heterogeneous Acid Catalyst ◽  
Gel Technique ◽  
Optimized Conditions

Heterogeneous acid catalyst, H4SiW6Mo6O40/SiO2 was synthesized by a sol-gel technique. Catalytic application of the catalyst for synthesis of acetals and ketals were tested. The variation of different reaction parameters on the yield of acetals and ketals were also studied. The yields of acetals and ketals can reach 80.0%~96.9% at the optimized conditions. The high activity and stability of the catalyst is well retained after 4 runs. The results reveal that the H4SiW6Mo6O40/SiO2 catalysis is a novel, effective and reusable catalyst for synthesizing actetals and ketals.

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