Enantioselective Friedel - Crafts Reactions of Aromatic Amines with Ethyl Glyoxylate in Pyridinium-Based Ionic Liquids

2006 ◽  
Vol 59 (7) ◽  
pp. 468 ◽  
Author(s):  
Sanjay V. Malhotra ◽  
Ying Xiao
Keyword(s):  
Ionic Liquids ◽  
Reaction Time ◽  
Metal Complexes ◽  
Reaction Temperature ◽  
Aromatic Amines ◽  
Reaction Parameters ◽  
Chiral Catalysts ◽  
Mild Conditions ◽  
Solvent Systems ◽  
High Yields

The Friedel–Crafts reactions of aromatic amines with ethyl glyoxylate in pyridinium-based ionic liquids (ILs) are investigated using 2,2′-dihydroxy-1,1′-binaphthyl (BINOL) metal complexes as chiral catalysts. Reaction parameters such as the catalyst–IL compositions, reactant compositions, reaction time, and reaction temperature are studied. High yields and excellent enantioselectivities are achieved under the relatively mild conditions. The ILs can also be recycled and reused as opposed to traditional solvent systems.

scholarly journals High Performance Redox Initiating Systems Based on the Interaction of Silane with Metal Complexes: A Unique Platform for the Preparation of Composites

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1602
Author(s):  
Ahmad Arar ◽  
Haifaa Mokbel ◽  
Frédéric Dumur ◽  
Jacques Lalevée
Keyword(s):  
Metal Complexes ◽  
Aromatic Amines ◽  
High Performance ◽  
Room Temperature ◽  
Hazardous Substances ◽  
Gel Time ◽  
Chemical Mechanisms ◽  
Mild Conditions ◽  
Spin Resonance ◽  
Methacrylate Monomers

Currently, Redox Initiating Systems (RISs) of Free Radical Polymerization (FRP) are mainly based on the interaction of aromatic amines with peroxides (e.g., dibenzoyl peroxide (BPO)) that can be both toxic and unstable. In the present work, we aim to replace these hazardous substances in new RIS that can be peroxide-free and amine-free. Our redox two components (2K) initiating system is based on diphenylsilane (DPS) as reducing agent combined with different metal complexes (Mn(acac)2, Cu(AAEMA)2 or Fe(acac)3) as oxidizing agents. For the new proposed RIS, an excellent reactivity is found for the polymerization of benchmark methacrylate monomers under mild conditions (redox polymerization done under air and at room temperature); remarkably, it is also possible to finely control the gel time. Different techniques (optical pyrometry, Real-Time FTIR spectroscopy, Cyclic Voltammetry and Electron Spin Resonance (ESR)) were used to follow the polymerization processes but also to shed some light on the new redox chemical mechanisms.

Transesterification of Natural Lecithin Catalyzed by Isopropylamine

2014 ◽  
Vol 884-885 ◽  
pp. 603-606
Author(s):  
Hong Ya Li ◽  
Biao Yan ◽  
Xiao Li Zhang ◽  
Bin Xia Zhao
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Boiling Point ◽  
Transesterification Reaction ◽  
Reaction Volume ◽  
Effective Catalyst ◽  
Total Reaction ◽  
Mild Conditions ◽  
Catalyst Content

The isopropylamine with low boiling point was used for preparing GPC from natural lecithin under mild conditions, it was confirmed as an effective catalyst and the recovery can be combined with the recovery of methanol by distillation. The mechanism of the transesterification reaction was proposed and the experiments obtained the better effect under the conditions of: catalyst content was 2.4% of the total reaction volume, lecithin concentration was 0.05-0.10mol L1 , reaction temperature was 60 °C and reaction time was 260 min.

scholarly journals Regioselective chlorination and bromination of unprotected anilines under mild conditions using copper halides in ionic liquids

2012 ◽  
Vol 8 ◽  
pp. 744-748 ◽  
Author(s):  
Han Wang ◽  
Kun Wen ◽  
Nurbiya Nurahmat ◽  
Yan Shao ◽  
He Zhang ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Para Position ◽  
Mild Conditions ◽  
High Yields ◽  
Copper Halides

By using ionic liquids as solvents, the chlorination or bromination of unprotected anilines at the para-position can be achieved in high yields with copper halides under mild conditions, without the need for potentially hazardous operations such as supplementing oxygen or gaseous HCl.

A highly effective and mild protocol for the production of 1-thioamidoalkyl-2-naphthols using 1,3-disulfonic acid imidazolium trifluoroacetate as a dual-functional catalyst

2018 ◽  
Vol 73 (5) ◽  
pp. 289-293 ◽  
Author(s):  
Mostafa Karami ◽  
Abdolkarim Zare
Keyword(s):  
Ionic Liquid ◽  
Reaction Time ◽  
Reaction Times ◽  
Solvent Free ◽  
Disulfonic Acid ◽  
One Pot ◽  
Mild Conditions ◽  
Dual Functional ◽  
Highly Effective ◽  
High Yields

AbstractA solvent-free protocol for the production of 1-thioamidoalkyl-2-naphthols via a one-pot multi-component reaction of arylaldehydes with 2-naphthol and thioacetamide using the ionic liquid 1,3-disulfonic acid imidazolium trifluoroacetate ([Dsim][TFA]) is described. Furthermore, a plausible and attractive mechanism based on the dual functionality of the catalyst is proposed. Because of the dual functionality of [Dsim][TFA] (possessing acidic and basic sites), it is found to be generally highly effective, affording the products in high yields and short reaction times under mild conditions. We claim that this is one of the best protocols for the synthesis of 1-thioamidoalkyl-2-naphthols (in terms of yield, temperature, conditions, and/or the reaction time).

Synthesis and Preparation of Desulfurization Concerned Naphthenic Acid Type Ionic Liquid

2014 ◽  
Vol 670-671 ◽  
pp. 224-228
Author(s):  
Qiang Wang ◽  
Guo Bi Li ◽  
Peng Cheng ◽  
Shi Dong Wang ◽  
Shu Liang Zang
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Reaction Time ◽  
Crude Oil ◽  
Reaction Temperature ◽  
Naphthenic Acid ◽  
Process Conditions ◽  
Liquid Density ◽  
Physical Measurements ◽  
Acid Type

This paper describes the types and characteristics of ionic liquids, synthesis and application of ionic liquids in chemical and environmental applications, and naphthenic acid corrosion problems and research on ionic liquids are organically combined together, using properties, good stability and easy separating from crude oil, of ionic liquid generated by imidazole and naphthenic acid, exploring the ionic liquid deacidification process conditions and acid removal effect. The naphthenic acid and imidazole react in acetone solvent, synthesis a series of ionic liquids in different reaction ratio, reaction temperature, reaction time and stirring speed conditions,makesome physical measurements and calculation of the yield of these ionic liquids and. The results show that, in naphthenic acid and imidazole molar ratio of 1:1, reaction temperature 70°C, reaction time 7h, stirring speed 400R / min, stand half hour after reaction, the yield of naphthenic acid type ionic liquid is maximum, namely, the deacidification effect is best. At the same time measured in the ionic liquid density is 1.179g / mL, and pH is 5.8. Obtained optimum synthesis condition of naphthenic acid type ionic liquid, greatly improving the deacidification rate of high acid crude oil, more importantly, the method does not cause any pollution to the environment.

A Study on the Sulfonation of Aromatic Amines with Sulfuric Acid under Microwave Irradiation

2003 ◽  
Vol 2003 (8) ◽  
pp. 493-494 ◽  
Author(s):  
Hui-Zhang Li ◽  
Li-Wei Xiao ◽  
Hong-Ya Li ◽  
Kai-Fang Wang ◽  
Xu Li
Keyword(s):  
Sulfuric Acid ◽  
Reaction Time ◽  
Microwave Irradiation ◽  
Aromatic Amines ◽  
Solvent Free ◽  
Short Reaction Time ◽  
Solvent Free Conditions ◽  
High Yields

The sulfonation of aromatic amines with high yields, simple operations and short reaction time has been studied under microwave irradiation in solvent-free conditions.

Esterification of Menthol and Lactic Acid by Silicotungstic Acid Catalyst Supported on Bentonite

2013 ◽  
Vol 634-638 ◽  
pp. 647-650
Author(s):  
Jian Zhong Jin ◽  
Na Bo Sun
Keyword(s):  
Lactic Acid ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Acid Catalyst ◽  
Molar Ratio ◽  
Main Reaction ◽  
Silicotungstic Acid ◽  
Optimum Conditions ◽  
Reaction Parameters ◽  
Acid Loading

The silicotungstic acid catalyst supported on bentonite was employed in the esterification of menthol and lactic acid. The main reaction parameters were silicotungstic acid loading on bentonite, the amounts of catalyst, molar ratio of reactants, reaction temperature and reaction time. The optimum conditions were determined as follows : silicotungstic acid loading on bentonite 50 wt %, catalyst 1.25 g , mole ratio of menthol to lactic acid 1:1.1, reaction temperature 130 °C and reaction time 3 h . The esterification yield of menthyl lactiate was about 83.97 %. The catalyst could be used repeatedly for many times without distinct loss in activity.

scholarly journals Optimization of lipase-catalyzed synthesis of flavour esters in solvent free system

2014 ◽  
Vol 6 (1) ◽  
Author(s):  
Syamsul Kamar Muhamad ◽  
Salina Mat Radzi ◽  
Siti Salhah Othman ◽  
Mohd Basyaruddin Abdul Rahman ◽  
Hanina Mohd Noor
Keyword(s):  
Reaction Time ◽  
Chain Length ◽  
Reaction Temperature ◽  
Immobilized Lipase ◽  
Solvent Free ◽  
Esterification Reaction ◽  
Reaction Parameters ◽  
Free System ◽  
Solvent Free System ◽  
Flavour Esters

The effects of important reaction parameters for enhancing flavour esters formation through lipase-catalyzed reaction were investigated in this study.Various commercial immobilized lipases were used to catalyze the esterification reaction between short-chain fatty acids and alcohols to produce flavour esters which are nonyl caprylate and ethyl valerate which differ in chain length of esters. These synthetic flavour esters with fruity notes are widely used in food, cosmetic and pharmaceutical industries. The effect of various reaction parameters was optimized to obtain a high yield of flavour esters. A maximum percentage for nonyl caprylate with conversion of flavour esters more than 90 % in a solvent-free system was successfully obtained under the following conditions: reaction time (RT), 5 hours; reaction temperature, 40 °C; amount of immobilized lipase, 25 % w/w of total substrate and shaking speed 200 rpm. Compared to ethyl valerate, a maximum percentage conversion of flavour ester more than 80 % in solvent free system was successfully obtained under following conditions: reaction time (RT), 45 minutes; reaction temperature, 40 °C; amount of immobilized lipase, 15 % w/w of total substrate and shaking speed 200 rpm. Comparison between these two ester showed that the chain length give an effect to optimize the reaction condition in esterification reaction.

Diacylglycerols from Palm Oil Deodoriser Distillate. Part 1 – Synthesis by Lipase-catalysed Esterification

2004 ◽  
Vol 10 (3) ◽  
pp. 149-156 ◽  
Author(s):  
S. K. Lo ◽  
B. S. Baharin ◽  
C. P. Tan ◽  
O. M. Lai
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Reaction Time ◽  
Water Content ◽  
Reaction Temperature ◽  
Palm Oil ◽  
Molecular Sieves ◽  
Molar Ratio ◽  
Reaction Parameters ◽  
Lipozyme Rm Im

Diacylglycerols (DAG) were synthesised by lipase-catalysed esterification of glycerol with fatty acids from palm oil deodoriser distillate (PODD). Effects of reaction parameters such as reaction time, temperature, enzyme type, enzyme load, substrate mole ratio and water content were determined. The effect of molecular sieves as a water adsorbent was also studied. Rhizomucor mieheilipase (Lipozyme RM IM) was found to be most effective among the lipases screened for DAG production. The following conditions yielded 52% (w/w) DAG: 6h reaction time, 65 °C reaction temperature, 10% (w/w) Lipozyme RM IM, 2.5:1 fatty acid to glycerol molar ratio, and 30% (w/w) molecular sieves. DAG synthesis of 10.9% (w/w) was still observed at 10% (w/w) water content.

scholarly journals An Efficient Greener Approach for N-acylation of Amines in Water Using Benzotriazole Chemistry

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2501 ◽  
Author(s):  
Tarek S. Ibrahim ◽  
Israa A. Seliem ◽  
Siva S. Panda ◽  
Amany M. M. Al-Mahmoudy ◽  
Zakaria K. M. Abdel-Samii ◽  
...  
Keyword(s):  
Amino Acid ◽  
Reaction Time ◽  
Microwave Irradiation ◽  
Room Temperature ◽  
Efficient Synthesis ◽  
Short Reaction Time ◽  
Mild Conditions ◽  
Drug Conjugates ◽  
Cost Efficient ◽  
High Yields

A straightforward, mild and cost-efficient synthesis of various arylamides in water was accomplished using versatile benzotriazole chemistry. Acylation of various amines was achieved in water at room temperature as well as under microwave irradiation. The developed protocol unfolds the synthesis of amino acid aryl amides, drug conjugates and benzimidazoles. The environmentally friendly synthesis, short reaction time, simple workup, high yields, mild conditions and free of racemization are the key advantages of this protocol.

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