A Review on Solvent

The purpose of green chemistry is to provide a path that reduces or eliminates the use of such hazardous toxic solvents. Therefore, the key factor of the green synthetic approach is to utilize renewable materials, nontoxic chemical and to perform the reactions under solvent-free conditions.

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Expo Cinetica

Hernndez, J. G., Juaristi, E., Efcient ball-mill procedure in the green asymmetric aldol reaction organocatalyzed by (S)-proline-containing dipeptides in the presence of

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A Green Synthesis and Antibacterial Activity of N

A green method has been developed for the synthesis of N -arylsulfonylhydrazones via a simple grindstone procedure. By grinding mixtures of benzensulfonyl hydrazides and a series of aryl aldehydes or ketones in the mortar using L-tyrosine as catalyst, 24 N -arylsulfonylhydrazones were synthesized in a few minutes with high yield. All compounds were screened for their antibacterial activities

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972 results in SearchWorks catalog

High-yielding asymmetric synthesis of bioactive and natural products through mild catalysis is an efficient approach in reaction engineering. In the early days, synthetic chemists mainly focused on the synthesis of complex molecules, with less attention on the reaction efficiency

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A highly efficient solvent

Jul 04, 2008Three different methods are assayed: simple conventional magnetic stirring, magnetic stirring after previous dissolution in THF and evaporation, and ball mill technique. These procedures allow one to reduce not only the amount of required ketone to 2 equiv but also the reaction time to give the aldol products with regio-, diastereo-, and

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"Ball Milling Towards Green Synthesis: Applications

Chapter 5, 'Cross Dehydrogenative Coupling Reactions by Ball Milling' by Jingbo Yu, Zhijiang Jiang and Weike Su (Zhejiang University of Technology, China) confirms how ball milling can promote cross dehydrogenative coupling (CDC) and asymmetric CDC reactions. This method efficiently provides C–C bonds directly from C–H bonds.

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Mechanochemical synthesis of small organic molecules

Aldol reaction In 2000, Raston and Scott first reported the aldol condensation reaction using veratraldehyde, 4-phenylcyclohexanone and 1-indanone in the presence of NaOH in a vibrating ball mill and the products were obtained in the yield up to 98% within 10 min (Scheme€1) [48]. Scheme 1: Mechanochemical aldol condensation reactions [48].

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Разработка каталитических систем для осуществления

132. Hernndez J.G., Juaristi E. Efficient ball-mill procedure in the 'green' asymmetric aldol reaction organocatalyzed by (S)-proline-containing dipeptides in the presence of water// Tetrahedron Lett., 2011, Vol. 67, № 36, P. 6953-6959 133.

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Recent efforts directed to the development of more

Feb 09, 2012Pioneers in this field, Bolm et al., reported that the asymmetric aldol reaction under solvent-free conditions and catalyzed by (S)-proline (10 mol%) in a ball mill, employing a 1.1: 1 ketone/aldehyde ratio, proceeded efficiently to give selectively the anti-aldol diastereomeric products in high yields and with up to 99% enantiomeric excess

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efficient ball mill procedure in the green asymmetric

Efficient ball-mill procedure in the 'green' asymmetric aldol reaction organocatalyzed by (S)-proline-containing dipeptides in the presence of water. Tetrahedron 2011, 67 (36), 6953-6959. More

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A Mini

A Mini-Review: Achievements in the Thiolysis of Epoxides. Author (s): Zhihua Chen, Institute of Computing Science and Technology, Guangzhou University, Guangzhou 510006, China. Saeed Mohammadi Nasr, Independent Researcher, Jowlan 65136-8942, Hamedan, Iran. Mosstafa Kazemi*, Department of Chemistry, Faculty of Science, Ilam University, PO Box

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Bio

Organic chemists solved quickly the problem of pollutants by performing the reaction under solvent-free conditions. 7 A similar reaction performed under ball mill conditions gave the same aldol product 3a in 73% yield and 56% ee. 8 However, in this new protocol, the final work-up using a large amount of diethyl ether (about 80 mL mmol −1) returns us the initial problems associated with the

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Water versus Solvent

The direct asymmetric aldol reaction[1] reaction times and result in simple and efficient workup procedures.[9] For these reasons, efficacy of catalyst 1d was similar when the reaction was performed in a ball mill[9a,9b] (Table 1, entry 10). Recently, remarkable rate acceleration of solvent-free organic reactions has been

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Asymmetric Catalysis

This article describes a study on the Michael addition reaction of cyclohexanone to nitroolefins catalyzed by the chiral secondary amine (1S,4S)-2-tosyl-2,5-diazabicyclo[2.2.1]hep

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Solvent

solvent media. The first solvent-free intermolecular aldol reaction involved the use of a ball mill [22]. This technique [23] is widely applied in grinding minerals and solids into fine particles and it was used in this transformation in order to enhance the efficient mixing of reagents and the catalyst. The best results

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Introducing mechanochemistry

James and Crawford have also explored the use of twin-screw extrusion in organic synthesis. 6 They have demonstrated four different types of condensation reactions on the large scale (0.5kg per hour) in a continuous, solvent-free environment: Knoevenagel condensation, imine formation, aldol reaction and Michael addition. In many cases, the

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in Organic Synthesis under Solvent

Aug 06, 2020One of the most thoroughly studied organocatalytic reactions is the aldol reaction, since it constitutes one of the most useful strategies for the formation of C-C bonds. In a seminal work reported in 2006, Bolm et al. carried out asymmetric aldol reactions by means of chiral organocatalysts in a ball mill with excellent results [57,58].

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Asymmetric Catalysis

[23] Hernndez J.G., Juaristi E., Efficient ball-mill procedure inthe 'green' asymmetric aldol reaction organocatalyzed by(S)-proline-containing dipeptides in the presence of

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Dr. Eusebio Juaristi y Cosio

J.G. Hernndez y E. Juaristi, "Efficient Ball-Mill Procedure in the "Green" Asymmetric Aldol Reaction Organocatalyzed by (S)-Proline-Containing Dipeptides in the Presence of Water", Tetrahedron, 67, 6953-6959 (2011).

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Ricard Sola Mestres

Ball mill and microwave assisted synthetic routes to Fluoxetine Sustainable Chemistry and Pharmacy 2017, 5, 14-21 24 grudnia 2016 Remarkable advances have been made in the development of an environmentally-friendly approach for the rapid and simple construction of the Active Pharmaceutical Ingredient (API) Fluoxetine (1).

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Stereoselective Synthesis

A Highly Efficient Asymmetric Organocatalytic Aldol Reaction in a Ball Mill B. Rodrguez, A. Bruckmann, C. Bolm, Chem. Eur. J. 2007, 13, 4710–4722. Synthesis of Novel Chiral Phosphine-Olefin Complexes and their Evaluation as Ligands in the Rhodium-Catalyzed Asymmetric 1,4-Addition R. T. Stemmler, C. Bolm, Synlett 2007, 1365–1370.

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Aqueous formic acid: an efficient, inexpensive and

Aug 12, 2014In this article, we present a convenient and green method for synthesis of β-amino carbonyl compounds through ball-milling technique by using aqueous formic acid, which is an inexpensive and highly efficient catalyst. This multi-component reaction was done at room temperature with high anti-selectivity and easy workup. The use of solvent-free ball-milling technique helped to

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Prolinamides Bearing Thiourea Groups as Catalysts for

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[PDF] Use of (R)

Efficient ball-mill procedure in the 'green' asymmetric aldol reaction organocatalyzed by (S)-proline-containing dipeptides in the presence of water J. G. Hernndez, E. Juaristi Chemistry

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BJOC

Sep 11, 2017Aldol reaction. In 2000, Raston and Scott first reported the aldol condensation reaction using veratraldehyde, 4-phenylcyclohexanone and 1-indanone in the presence of NaOH in a vibrating ball mill and the products were obtained in the yield up to 98% within 10 min .

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Molecules

Hernndez, J.G.; Juaristi, E. Efficient ball-mill procedure in the 'green' asymmetric aldol reaction organocatalyzed by (S)-proline-containing dipeptides in the presence of water. Tetrahedron 2011, 67, 6953–6959. [Google Scholar]

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Asymmetric organocatalysis in a ball mill

In this video the authors present asymmetric organocatalyses performed in a ball mill. Three reaction types are being discussed: enantioselective aldol reactions, asymmetric Michael additions to nitro alkenes and dipeptide formations. In the laboratory the ball milling device is shown, and reaction details are revealed. Finally, future applications of mechanochemical biomass degradations are

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mill ming dynasty efficient

Prosperity in Song China (960-1279) (video) | Khan Academy. But for the most part, it is a very prosperous time for China. The population actually grows from roughly 50 million people during the Tang dynasty, to, it is estimated, 100 million people by the Northern Song dynasty and eventually keeps growing so that by the time we get to the Ming dynasty, we have a population of about 200 million

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Green Solvents Fundamental and Industrial Applications

The toxicity and volatile nature of many organic solvents, widely utilized in huge amounts for organic reactions, have posed a serious threat to the environment. Thus, the principles of green

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BJOC

Oct 19, 2012Aldol reaction. Since the origin of organocatalysis, the asymmetric aldol reaction has been one of the most intensely studied reactions, providing an easy access to chiral β-hydroxycarbonyl compounds, which are important building blocks for various bioactive molecules .Among different organocatalysts used for asymmetric aldol reactions, proline and its derivatives emerged as

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IF:4.45 (4) An Organocatalytic Domino Thia-Michael/Aldol Condensation Reaction: Highly Enantioselective Synthesis of Functionalized Dihydrothiophenes, Adv. Synth. Catal., 2010, 352, 2121. IF:6.048 (5) Fast, solvent-free and hydrogen-bonding-mediated asymmetric Michael addition in a ball mill, Green Chem., 2012, 14 (4), 893. IF:6.32

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Reacciones asimtricas organocatalizadas en ausencia de

Efficient ball-mill procedure in the 'green' asymmetric aldol reaction organocatalyzed by (S)-proline-containing dipeptides in the presence of water. Tetrahedron, 67 (2011), pp.

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