scholarly journals Mathematical modeling and multiobjective optimization complex catalyst hydroalumination reaction of olefins with diisobutylaluminium hydride

2021 ◽  
Vol 2131 (2) ◽  
pp. 022015
Author(s):  
K F Koledina ◽  
I M Gubaydullin ◽  
S N Koledin
Keyword(s):  
Maximum Yield ◽  
Organoaluminum Compound ◽  
Variable Order ◽  
Sampling Point ◽  
Step Method ◽  
Complex Catalyst ◽  
Reaction Conditions ◽  
Diisobutylaluminum Hydride ◽  
Detailed Kinetic Model ◽  
Subsequent Introduction

Abstract A mathematical model for the catalyst hydroalumination reaction of olefins with diisobutylaluminium hydride has been developed. In solving the direct kinetic problem applies multi-step method Gere variable order. When solving systems of ordinary differential equations in chemical kinetics, it is necessary to fulfill the balance relations at each sampling point. That ensures the fulfillment of the law of conservation of matter and the convergence of the numerical method. For the catalytic reaction of hydroalumination olefins in the presence of the organoaluminum compound diisobutylaluminum hydride, the problem of multicriteria optimization reaction conditions was solved based on a detailed kinetic model. The solutions found make it possible to optimally select the reaction conditions to achieve the maximum yield of target products, which can be based on the subsequent introduction of the laboratory reaction into production.

scholarly journals Preparation of Glucosamine Hydrochloride from Indigenous Shrimp Processing Waste

1970 ◽  
Vol 46 (3) ◽  
pp. 375-378 ◽  
Author(s):  
MM Islam ◽  
SM Masum ◽  
MM Rahman ◽  
AA Shaikh
Keyword(s):  
Maximum Yield ◽  
Therapeutic Activity ◽  
Processing Waste ◽  
Reaction Conditions ◽  
Glucosamine Hydrochloride ◽  
Glycoside Linkage ◽  
Shrimp Shell ◽  
Reaction Proceeds ◽  
Ft Ir ◽  
Hydrolysis Of

The present investigation described the effective preparation of glucosamine hydrochloride (GluHCl) from chitin which was extracted from indigenous shrimp shell. GluHCl has attracted much attention owing to its therapeutic activity in osteoarthritis and widely used dietary supplement. The key step involved was extraction of chitin from shrimp skeleton and then hydrolysis of chitin by concentrated hydrochloric acid. The reaction proceeds via break down of glycoside linkage. Structural analysis was carried out by melting point, TLC, FT-IR, elemental analysis and all the data were compared with that of standard GluHCl. The elemental (C, 32.75; H, 6.51; N, 6.20) analysis is good concord with the calculated value (C, 33.42; H, 6.54; N, 6.50). Absence of v max at 1726 cm-1 indicates that GluHCl is a deacetylated product of chitin. The yields of the product mainly depend on reaction conditions. Maximum yield (63.5%) was obtained when chitin was hydrolyzed with concentrated HCl for 1.30 h. Key words: Shrimp shell; Chitin, Acid hydrolysis; Glucosamine hydrochloride Osteoarthritis. DOI: http://dx.doi.org/10.3329/bjsir.v46i3.9046 BJSIR 2011; 46(3): 375-378

Synthesis of the Carboxyl and Pyridine Functional Ionic Liquids

2014 ◽  
Vol 513-517 ◽  
pp. 246-250 ◽  
Author(s):  
Ying Xiong ◽  
Min Yang
Keyword(s):  
Ionic Liquids ◽  
Reaction Time ◽  
Anion Exchange ◽  
Room Temperature ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Maximum Yield ◽  
Step Method ◽  
Strong Base ◽  
One Step

The effects of different solvents on synthesis of base functional ionic liquid, butyl pyridinium hydroxide ([bPy]OH), from butyl pyridinium bromine ([bPy]Br) were investigated systematically using KOH/NaOH as the base agent and strong base anion exchange resin. The results showed that the yield of [bPy]OH achieved 35% with the molar ratio of 1:1.1 ([bPy]Br to NaOH) using dichloromethane under room temperature. With isopropanol and 8 h of the reaction time, the yield could reach 88% with byproducts. The yield of 97% without byproduct was achieved by using strong base anion exchange resin in column chromatography static reaction for 0.25 h. The yield of carboxyl and pyridine functional ionic liquids based on neutralization method, exchange method and one-step method were compared and the results showed that the one-step method possessed the maximum yield of 88% with 3 h of the reaction time at room temperature.

scholarly journals Synthesis, Structural Characterization and Catalytic Activity of A Cu(II) Coordination Polymer Constructed from 1,4-Phenylenediacetic Acid and 2,2’-Bipyridine

2017 ◽  
Vol 12 (1) ◽  
pp. 113 ◽  
Author(s):  
Wang Li-Hua ◽  
Liang Lei ◽  
Wang Xin
Keyword(s):  
Catalytic Activity ◽  
Coordination Polymer ◽  
Polymer Material ◽  
Structural Characterization ◽  
Maximum Yield ◽  
Coupling Reaction ◽  
X Ray Diffraction ◽  
Complex Catalyst ◽  
Distorted Octahedral ◽  
Good Catalytic Activity

<p>In order to study the catalytic activity of Cu(II) coordination polymer material, a novel 1D chained Cu(II) coordination polymer material, [CuL(bipy)(H<sub>2</sub>O)<sub>5</sub>]n (A1) (H<sub>2</sub>L = 1,4-phenylenediacetic acid, bipy = 2,2’-bipyridine), has been prepared by the reaction of 1,4-phenylenediacetic acid, 2,2’-bipyridine, Cu(CH<sub>3</sub>COO)<sub>2</sub>·H<sub>2</sub>O and NaOH. The composition of A1 was determined by elemental analysis, IR spectra and single crystal X-ray diffraction. The results of characterization show that each Cu(II) atom adopts six-coordination and forms a distorted octahedral configuration. The catalytic activity and reusability of A1 catalyst for A<sup>3</sup> coupling reaction of benzaldehyde, piperidine, and phenylacetylene have been investigated. And the results show that the Cu(II) complex catalyst has good catalytic activity with a maximum yield of 54.3% and stability. Copyright © 2017 BCREC GROUP. All rights reserved</p><p><em>Received: 21<sup>st</sup> October 2016; Revised: 17<sup>th</sup> November 2016; Accepted: 22<sup>nd</sup> November 2016</em></p><p><strong>How to Cite:</strong> Li-Hua, W., Lei, L., Xin, W. (2017). Synthesis, Structural Characterization and Catalytic Activity of A Cu(II) Coordination Polymer Constructed from 1,4-Phenylenediacetic Acid and 2,2’-Bipyridine. <em>Bulletin of Chemical Reaction Engineering &amp; Catalysis</em>, 12 (1): 113-118 (doi:10.9767/bcrec.12.1.735.113-118)</p><p><strong>Permalink/DOI:</strong> http://dx.doi.org/10.9767/bcrec.12.1.735.113-118</p><p> </p>

scholarly journals Rigid and concave, 2,4-cis-substituted azetidine derivatives: A platform for asymmetric catalysis

2018 ◽  
Author(s):  
Akina Yoshizawa ◽  
Antonio Feula ◽  
Louise Male ◽  
Andrew G. Leach ◽  
John Fossey
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Asymmetric Catalysis ◽  
Enantiomeric Excess ◽  
Platinum Complex ◽  
Crystal Structure Analysis ◽  
Single Crystal Structure ◽  
Complex Catalyst ◽  
Reaction Conditions ◽  
Absolute Stereochemistry

A series of single enantiomer, 2,4-<i>cis</i>-disubstituted amino azetidines were synthesised and used as ligands for copper-catalysed Henry reactions of aldehydes with nitromethane. Optimisation of ligand substituents and the reaction conditions was conducted. The enantiomeric excess of the formed products was highest when alkyl aldehydes were employed in the reaction (>99% e.e.). The absolute stereochemistry of one representative azetidine derivative salt was determined by analysis of the Flack parameter of an XRD single crystal structure. The origin of selectivity in catalysis was investigated computationally, revealing the importance of the amino-substituent in determining the stereochemical outcome. A racemic platinum complex of a <i>cis</i>-disubstituted azetidine is examined by XRD single crystal structure analysis with reference to its steric parameters, and analogies to the computationally determined copper complex catalyst are drawn.<br>

Production of Biodiesel in Supercritical Methanol and Related Correlation on Phase Equilibrium

2012 ◽  
Vol 560-561 ◽  
pp. 555-562 ◽  
Author(s):  
Dan Zeng ◽  
Yang Li ◽  
Tao Fang
Keyword(s):  
Phase Equilibrium ◽  
Soybean Oil ◽  
Orthogonal Experiment ◽  
Methyl Esters ◽  
Maximum Yield ◽  
Influential Factors ◽  
Supercritical Methanol ◽  
Reaction Conditions ◽  
Equilibrium Data ◽  
Final Yield

Biodiesel was prepared by methyl esterification and effects of different reaction conditions on the yield of fatty acid methyl esters (FAMEs) were investigated. The result of the orthogonal experiment analysis shows that the order of influential factors is ranked as reaction temperature > methanol-to-soybean-oil (M/O) ratio > reaction time. The maximum yield of 94.8 % has been achieved by reacting supercritical methanol and soybean oil in M/O ratio 4:2 (v/v) at 573 K for 45 min. Moreover, the higher M/O ratio, the higher yield of FAMEs will be obtained. At the temperature ranging from 533 k to 573 k, the yield rises significantly; however, since soybean oil decomposes over 573 K, the yield decreases oppositely. Time longer than 45 min has less effect on the final yield. In addition, the phase equilibrium data of supercritical methanol + C12 methyl esters and supercritical methanol + C18 methyl esters were separately correlated using the Peng-Robinson (PR) equation of state (EOS) with the Adachi-Sugie (AS) mixing rule.

Fabrication and Coagulation Phenomena of ZnO Microsphere Particles

2014 ◽  
Vol 638-640 ◽  
pp. 1341-1345
Author(s):  
Gang Yin Yan
Keyword(s):  
Chemical Reaction ◽  
Solution Method ◽  
Generation Mechanism ◽  
Reaction Process ◽  
Zno Films ◽  
Step Method ◽  
Reaction Conditions ◽  
Vertical Deposition ◽  
Seed Solution

The uniform ZnO microsphere particles with a diameter of 390nm were synthesized by two-step method (also named seed solution method) projected by Eric W. Seelig. The chemical reaction details in the container were analyzed and the generation mechanism of ZnO microsphere particles was studied. ZnO films were prepared by vertical deposition. Coagulation phenomena occurred during the reaction process. The reaction conditions of coagulation phenomena were summarized and given reasonably explanations.

Efficient Synthesis of Arylaldehyde Oxime Ethers Functionalised with 3,4-dihydropyrimidinones and 2,5-quinazolinediones via a One-pot Two-step Method

2013 ◽  
Vol 37 (1) ◽  
pp. 30-33 ◽  
Author(s):  
Zheng-Jun Quan ◽  
Xue-Hong Tang ◽  
Yu-Xia Da ◽  
Zhang Zhang ◽  
Xi-Cun Wang
Keyword(s):  
Simple Procedure ◽  
Efficient Synthesis ◽  
Step Method ◽  
Reaction Conditions ◽  
One Pot

New arylahdehyde oxime ethers functionalised with N3-3,4-dihydropyrimidinone and 2,5-quinazolinedione groups were synthesised in moderate to good yields by the reaction of the corresponding 3,4-dihydropyrimidinones and quinazolinediones with paraformaldehyde and arylaldehyde oximes via a one-pot two-step strategy in the presence of chlorotrimethylsilane. The advantages of this method are the simple procedure, the high regioselectivity of the products and the mild reaction conditions.

Study on the Reaction Characteristics of Directional Synthesis of α-Terpineol from Turpentine

2013 ◽  
Vol 634-638 ◽  
pp. 424-432 ◽  
Author(s):  
Yan Gu ◽  
Zhen Dong Zhao ◽  
Jie Song ◽  
Dong Mei Li ◽  
Jing Wang ◽  
...  
Keyword(s):  
High Purity ◽  
Theoretical Basis ◽  
Influence Factors ◽  
Separation Problem ◽  
Step Method ◽  
Reaction Conditions ◽  
Uniform System ◽  
Reaction Characteristics ◽  
One Step ◽  
Optimal Reaction

There was rarely high-purity α-terpineol or pure-monomer α-terpineol in China due to difficulty in isolating α-terpineol and γ-terpineol. Aiming at the separation problem, α-terpineol was directional synthesized by one-step method in a uniform system. The influence factors of stereochemistry structure, thermodynamic analysis and stability of reactants, products and carbocations were researched, conducting the experiments in optimal reaction conditions. All the influence factors about generating trend of objective product α-terpineol and byproduct γ-terpineol were discussed and the reaction mechanism was studied. This paper provided certain theoretical basis on prepare high-purity α-terpineol.

scholarly journals Influence of Pd and Pt Promotion in Gold Based Bimetallic Catalysts on Selectivity Modulation in Furfural Base-Free Oxidation

Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1226
Author(s):  
Hisham K. Al Rawas ◽  
Camila P. Ferraz ◽  
Joëlle Thuriot-Roukos ◽  
Svetlana Heyte ◽  
Sébastien Paul ◽  
...  
Keyword(s):  
Aerobic Oxidation ◽  
Maximum Yield ◽  
Reaction Conditions ◽  
Optimum Reaction ◽  
Metal Ratio ◽  
Nanoparticulate Systems ◽  
Free Oxidation ◽  
Standard Techniques ◽  
Catalytic Performances

Furfural (FF) has a high potential to become a major renewable platform molecule to produce biofuels and bio-based chemicals. The catalytic performances of AuxPty and AuxPdy bimetallic nanoparticulate systems supported on TiO2 were studied in a base-free aerobic oxidation of furfural to furoic acid (FA) and maleic acid (MA) in water. The characterization of the catalysts was performed using standard techniques. The optimum reaction conditions were also investigated, including the reaction time, the reaction temperature, the metal ratio, and the metal loading. The present work shows a synergistic effect existing between Au, Pd, and Pt in the alloy, where the performances of the catalysts were strongly dependent on the metal ratio. The highest selectivity (100%) to FA was obtained using Au3-Pd1 catalysts, with 88% using 0.5% Au3Pt1 with about 30% of FF conversion at 80 °C. Using Au-Pd-based catalysts, the maximum yield of MA (14%) and 5% of 2(5H)-furanone (FAO) were obtained by using a 2%Au1-Pd1/TiO2 catalyst at 110 °C.

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