Microwave-assisted direct transformation of lignocellulose into methyl glycopyranoside in ionic liquid

Holzforschung ◽  
2020 ◽  
Vol 74 (3) ◽  
pp. 313-320 ◽  
Author(s):  
Takao Kishimoto ◽  
Mafuyu Saito ◽  
Satoshi Suzuki ◽  
Masahiro Hamada ◽  
Noriyuki Nakajima ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Microwave Irradiation ◽  
Microcrystalline Cellulose ◽  
Value Added ◽  
Reaction Conditions ◽  
Direct Transformation ◽  
Moderate Reaction ◽  
Microwave Assisted ◽  
Combined Use ◽  
Acid Catalyzed

AbstractRecently, conversion of lignocellulose into useful substances has attracted increasing attention. In our previous investigations, microcrystalline cellulose was successfully converted to methyl glucopyranosides (MeGlc) by the combined use of ionic liquid (IL) and microwave irradiation under moderate reaction conditions. In this study, lignocelluloses, including softwood, hardwood, and rice straw, were directly converted to methyl glycopyranosides (MG), including MeGlc, methyl mannopyranosides (MeMan), and methyl xylopyranosides (MeXyl) using acid-catalyzed methanolysis under microwave irradiation in ILs. Lignocellulose ball-milling was quite effective as a crucial process of increasing the yield of MG. Under the optimized reaction conditions, the molar yield of MeGlc reached 40% from softwood, which was a comparable yield from microcrystalline cellulose. MeXyl was also obtained in a 48% yield. These results showed that the combination of the dissolution of ball-milled lignocellulose in IL and the microwave-assisted methanolysis was an effective method of converting lignocellulose into a high-value-added substance.

scholarly journals Microwave-Assisted Asinger Synthesis of Thiazolines

2020 ◽  
Vol 3 (1) ◽  
pp. 27
Author(s):  
Raúl Eduardo Gordillo-Cruz ◽  
Liliana Gonzalez-Reyes ◽  
Milton Coporo-Reyes ◽  
Nieves Zavala-Segovia ◽  
Bernardo A. Frontana-Uribe ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Reaction Times ◽  
Reaction Conditions ◽  
Microwave Assisted

An array of 2,4-disubstituted thiazolines was obtained through Asinger reaction approach from the straightforward treatment of diverse aldehydes/ketones with 1-mercaptopropan-2-one, in the presence of NH3 assisted by microwave irradiation, displaying similar and sometimes higher yields, as well as shorter reaction times that traditional Asinger reaction conditions at room and lower temperatures.

scholarly journals Microwave Assisted Synthesis of 1,5-Benzothiazepines Using Greener Reaction Medium

2019 ◽  
Vol 31 (5) ◽  
pp. 993-996 ◽  
Author(s):  
Sanjay S. Kotalwar ◽  
Amol D. Kale ◽  
Ram B. Kohire ◽  
Vasant B. Jagrut
Keyword(s):  
Reaction Time ◽  
Microwave Irradiation ◽  
Reaction Medium ◽  
Microwave Assisted Synthesis ◽  
Reaction Conditions ◽  
Renewable Sources ◽  
Microwave Assisted ◽  
High Yields

An efficient and eco-friendly synthesis of 1,5-benzothiazepines has been developed by the reaction of various 2-propen-1-ones with 2-aminothiophenol using microwave irradiation in greener reaction medium, glycerol. The clean reaction conditions, shorter reaction time, high yields and non-toxic, biodegradable reaction medium manufactured from renewable sources are unique features of this method.

A synergetic effect of ionic liquid and microwave irradiation on the acid-catalyzed direct conversion of cellulose into methyl glucopyranoside

Holzforschung ◽  
2018 ◽  
Vol 72 (12) ◽  
pp. 1025-1030
Author(s):  
Mafuyu Saito ◽  
Takao Kishimoto ◽  
Masahiro Hamada ◽  
Noriyuki Nakajima ◽  
Daisuke Urabe
Keyword(s):  
Ionic Liquid ◽  
Microwave Irradiation ◽  
Synergetic Effect ◽  
Acid Catalyst ◽  
Solvent System ◽  
Direct Conversion ◽  
Important Research Topic ◽  
Acid Catalyzed ◽  
Methyl Pyrrolidone

AbstractConversion of lignocellulose into useful chemicals is an important research topic in the area of biomass utilization. In this study, microcrystalline cellulose (MC) was dissolved in a mixed-solvent system containing the ionic liquid (IL) 1-allyl-3-methylimidazolium chloride ([Amim]Cl) andN-methyl-pyrrolidone (NMP), and the cellulose was directly converted into methyl glucoside (MG) by acid-catalyzed methanolysis aided by microwave irradiation (μWIr). Under moderate reaction temperature and pressure, and in the presence of acetyl chloride/methanol (in situformed HCl) as an acid catalyst, MG was obtained in a 42% yield. In contrast, in the absence of either IL or μWIr, the MG yield was only 5 or 21%, respectively. Both μWIr and the dissolution of cellulose in IL were quite effective for the conversion of cellulose into MG.

scholarly journals Microwave Assisted Three Component Reaction Conditions to Obtain New Thiazolidinones with Different Heterocyclic Skeletons

Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 38
Author(s):  
Fernando J. Lorenzo ◽  
Romina A. Ocampo ◽  
Sandra D. Mandolesi
Keyword(s):  
Microwave Irradiation ◽  
Thioglycolic Acid ◽  
Aldehyde Group ◽  
Green Solvent ◽  
Reaction Products ◽  
Reaction Conditions ◽  
One Pot ◽  
Microwave Assisted ◽  
Three Component Reaction ◽  
The One

We present here a new proposal for the “one pot” generation of new 4-thiazolidinones (9a–e) through a multicomponent reaction under microwave irradiation conditions, using aromatic and heteroaromatic amines (8a–e), absolute ethanol as a “green” solvent and modifying the aldehyde group in the glycosidic residue, synthesized from D-mannitol. The study is focused in the variation of the irradiation times and the concentration of thioglycolic acid in order to study the possibility of controlling the structure and/or stereochemistry of the products formed in the reaction. Thiazolidinones 9a–d were obtained with a 69–82% The generation of the corresponding reaction products were monitored by TLC and CG-MS, taking reaction aliquots. The conditions reaction proved to be chemoselective depending on the excess of acid and irradiation times.

scholarly journals Microwave Assisted One Pot Synthesis of 3,4-Dihydropyrano[c]chromene Derivatives using [Emim]OH Ionic Liquid as Novel Catalyst

2019 ◽  
Vol 31 (4) ◽  
pp. 829-833
Author(s):  
D.S. Bhagat ◽  
S.G. Pande ◽  
M.V. Katariya ◽  
R.P. Pawar ◽  
P.S. Kendrekar
Keyword(s):  
Ionic Liquid ◽  
Reaction Time ◽  
High Yield ◽  
Reaction Conditions ◽  
One Pot ◽  
Short Reaction Time ◽  
Aryl Aldehydes ◽  
Microwave Assisted ◽  
Novel Catalyst ◽  
Work Up

One-pot efficient protocol to the synthesis of 2-amino-5-oxo-4,5-dihydropyrano(3,2-c)chromene-3-carbonitrile derivatives via condensation of various aryl aldehydes, dicyanomethane and 4-hydroxycoumarin in presence of Emim hydroxide as an excellent homogeneous liquid catalyst. The key advantages of this methodology are mild reaction conditions, novel catalyst, short reaction time, eco-friendly, easy work-up procedure and high yield of isolation of derivatives.

scholarly journals Microwave-Assisted Resolution of α-Lipoic Acid Catalyzed by an Ionic Liquid Co-Lyophilized Lipase

Molecules ◽  
2015 ◽  
Vol 20 (6) ◽  
pp. 9949-9960 ◽  
Author(s):  
Ning Liu ◽  
Lei Wang ◽  
Zhi Wang ◽  
Liyan Jiang ◽  
Zhuofu Wu ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Lipoic Acid ◽  
Microwave Assisted ◽  
Acid Catalyzed

Sulfuric Acid-Catalyzed Conversion of Alkynes to Ketones in an Ionic Liquid Medium under Mild Reaction Conditions

ACS Catalysis ◽  
2011 ◽  
Vol 1 (2) ◽  
pp. 116-119 ◽  
Author(s):  
Wing-Leung Wong ◽  
Kam-Piu Ho ◽  
Lawrence Yoon Suk Lee ◽  
Kin-Ming Lam ◽  
Zhong-Yuan Zhou ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Sulfuric Acid ◽  
Liquid Medium ◽  
Reaction Conditions ◽  
Acid Catalyzed ◽  
Ionic Liquid Medium

Microwave-assisted Homogeneous Gold Catalyzed Organic Transformations

2020 ◽  
Vol 7 (3) ◽  
pp. 166-182
Author(s):  
Biswajit Panda
Keyword(s):  
Microwave Irradiation ◽  
Organic Molecules ◽  
Gold Catalysis ◽  
Chemical Processes ◽  
Microwave Chemistry ◽  
Organic Transformations ◽  
Reaction Conditions ◽  
Microwave Assisted ◽  
Interesting Insight ◽  
Insight Into

: Microwave chemistry is an emerging area of science mainly focusing on various applications of microwave energy into chemical processes. Microwave irradiation has enormous potential to provide controlled energy directly to the molecules of interest. On the other hand, homogeneous gold catalysis has emerged in the last two decades or so as one of the most promising fields in organic and organometallic chemistry. Its efficacy has been established many times for the construction of new C – X (X = O, N, S, etc.) and C – C bonds under mild reaction conditions. Although a significant number of reports have appeared in the literature regarding the homogeneous gold-catalyzed organic transformations under microwave conditions, this is the first review article which is going to appear in the literature. This mini-review is designed to give an interesting insight into various homogeneous goldcatalyzed organic reactions under microwave irradiation for the synthesis of a library of electronically and structurally diverse and biologically important organic molecules.

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