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efficient ball mill procedure in the green asymmetric aldol reaction

Water versus Solvent-free Conditions for the ...

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 ...

Asymmetric Aldol Reaction Organocatalyzed by (S)-Proline ...

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.

Mechanochemistry | Prof. Dr. Carsten Bolm

Organocatalytic Reactions: Effects of Ball Milling, Microwave and Ultrasound Irradiation A. Bruckmann, A. Krebs, C. Bolm, Green Chem. 2008, 10, 1131–1141. Solvent-free asymmetric anhydride opening in a ball mill T. Rantanen, I. Schiffers, C ... 2007, 349, 2213–2233. A Highly Efficient Asymmetric Organocatalytic Aldol Reaction in a Ball Mill ...

Highly Efficient Asymmetric Direct Stoichiometric Aldol ...

Angewandte Chemie DOI: 10.1002/ange.200703606 Asymmetric Synthesis Highly Efficient Asymmetric Direct Stoichiometric Aldol Reactions on/in Water** Junmin Huang, Xiaotong Zhang, and Daniel W. Armstrong* Many enzymes catalyze reactions in water under mild example, proline-catalyzed aldol reactions[10] can only afford conditions with high efficiency and excellent stereoselectivity.

ChemInform Abstract: Efficient Ball-Mill Procedure in the ...

ChemInform Abstract: Efficient Ball-Mill Procedure in the ′Green′ Asymmetric Aldol Reaction Organocatalyzed by (S)-Proline-Containing Dipeptides in the Presence of Water.

José G. Hernández – Senior Research Associate – Ruđer ...

Efficient Ball-Mill Procedure in the "Green" Asymmetric Aldol Reaction Organocatalyzed by (S)-Proline-Containing Dipeptides in the Presence of Water Tetrahedron Sept. 2011 The organocatalytic activity of (S)-proline-based dipeptides 1a–c has been evaluated in the asymmetric aldol reaction between representative ketones with various ...

BJOC - 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 .

(PDF) Proline−β 3 -Amino-Ester Dipeptides as Efficient ...

Efficient ball-mill procedure in the 'green' asymmetric aldol reaction organocatalyzed by ( S)-proline-containing dipeptides in the presence of water By Eusebio Juaristi Novel prolinamideeureas as organocatalysts for the asymmetric aldol reaction

Recent efforts directed to the development of more ...

Pioneers 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 ...

Natural low-molecular mass organic compounds with oxidase ...

Hernández JG, 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 (36):6953–6959.

The Ion Tag Strategy as a Route to Highly Efficient ...

José G. Hernández, Eusebio Juaristi, Efficient ball-mill procedure in the 'green' asymmetric aldol reaction organocatalyzed by (S)-proline-containing dipeptides in the presence of water, Tetrahedron, 10.1016/j.tet.2011.06.042, 67, 36, (6953-6959), (2011).

ChemInform: Vol 43, No 4 - Wiley Online Library

ChemInform Abstract: Efficient Ball‐Mill Procedure in the ′Green′ Asymmetric Aldol Reaction Organocatalyzed by (S)‐Proline‐Containing Dipeptides in the Presence of Water. Jose G. Hernandez; Eusebio Juaristi; First Published: 29 December 2011

Natural low-molecular mass organic compounds with oxidase ...

Hernández JG, Juaristi E. Efficient ball-mill procedure in the 'green' asymmetric aldol reaction organocatalyzed by (S)-proline-containing dipeptides in the presence of …

European Journal of Organic Chemistry: EarlyView ...

The asymmetric aldol reaction of an industrially viable synthesis of funapide, a promising analgesic agent, was studied with a range of squaramide catalysts. Compared to previously employed thiourea structures, these catalysts provided a non-negligible improvement in the enantioselectivity of the reaction, while keeping similar activity.

Ball Milling Towards Green Synthesis: Applications ...

Ball milling has emerged as a powerful tool over the past few years for effecting chemical reactions by mechanical energy. Allowing a variety of reactions to occur at ambient temperatures and in solvent-free conditions, ball milling presents a greener route for many chemical processes. Compared to the use of microwave and ultrasound as energy sources for chemical reactions, ball milling is not ...

Mechanochemical Organocatalysis: Do High ...

of asymmetric organocatalysis". Exploring the combination of organocatalysis with ball mills, Bolm and co-workers investigated the (S)-proline catalysed aldol reaction between ketones (1) and aromatic aldehydes (2), (Scheme 1).[125,126] They found that using 10 mol % of (S)-proline (C1), in a ball-mill with rotation speeds

Clean and Efficient One-Pot Synthesis of New 2-Oxo-2,3 ...

Ball milling is a mechanical technique widely used for grinding solids with balls in a rotating vial to obtain fine particles [1–4]. Ball milling has recently attracted increasing attention from organic chemists because of its simplicity, low cost, environmental friendliness, and capability to achieve high yields. Various organic reactions

Solvent-free one-pot synthesis of 1,2,3-triazole ...

Solvent-free one-pot synthesis of 1,2,3-triazole derivatives by the 'Click' reaction of alkyl halides or aryl boronic acids, sodium azide and terminal alkynes over a …

A Highly Efficient Asymmetric Organocatalytic Aldol ...

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]. Indeed, these experiments ...

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efficient ball mill procedure in the 'green' asymmetric aldol reaction. 2020/07/10. Efficient ballmill procedure in the 'green' asymmetric Sep 09, 2011 The organocatalytic activity of (S)prolinebased dipeptides 1a–c has been evaluated in the asym

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Catalysts | Free Full-Text | A Simple and Efficient ...

The proline-catalysed asymmetric aldol reaction is usually carried out in highly dipolar aprotic solvents (dimethylsulfoxide, dimethylformamide, acetonitrile) where proline presents an acceptable solubility. Protic solvents are generally characterized by poor stereocontrol (e.g., methanol) or poor reactivity (e.g., water). Here, we report that water/methanol mixtures are exceptionally simple ...

10.1016/j.tet.2011.06.042 | DeepDyve

The desired aldol products were obtained in high yields (up to 94%) and good enantioselectivities (up to 97% ee). 17a In addition, Li and co-workers examined dipeptide ( 1c -OH) in the asymmetric aldol reaction of different ketones and aldehydes in solid phase media (Al 2 O 3 ), using 1,4-diazabicyclo[2.2.2]octane as additive, observing ...

BJOC - Mechanochemistry assisted asymmetric ...

Aldol 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 …

Highly Efficient Small Organic Molecules for ...

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. DOI: 10.1016/j.tet.2011.06.042.

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Recent Advances in Sustainable Organocatalysis | IntechOpen

The recent advances on green and sustainable organocatalysis are revised in this chapter. An important focus on one of the 12 principles of green chemistry, organocatalysis pursues to reduce energy consumption as well as to optimize the use of different resources, targeting to become a sustainable strategy in organic chemical transformations.

Solvent-Free Transesterification in a Ball-Mill over ...

ChemInform Abstract: Efficient Ball-Mill Procedure in the ′Green′ Asymmetric Aldol Reaction Organocatalyzed by (S)-Proline-Containing Dipeptides in the Presence of Water. Article Sep 2011

[PDF] Use of (R)-Mandelic Acid as Chiral Co-Catalyst in ...

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

Bio-renewable enantioselective aldol reaction in natural ...

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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procedure to dry line powder It includes the dry and wet grinding line with ball mill vertical roller mill and so on procedure to dry lizenithne powder Most of the milk powder we make Get Price Milk PowderNZIC III-Dairy-C-Milk Powder-3 evaporator which may be operated at a lower pressure and temperature than the preceding effect.

ball milling asymmetric organocatalysis

Efficient Ball Mill Procedure In The Green Asymmetric . Ball Mill Reactions. Read "solventfree asymmetric organocatalysis in a ball mill" on deepdyveinstant access to the journals you need more efficient ball-mill procedure in the green efficient ball-mill procedure in the green asymmetric aldol reaction organocatalyzed by s. Chat Online

Efficient ball-mill procedure in the 'green' asymmetric ...

The organocatalytic activity of (S)-proline-based dipeptides 1a–c has been evaluated in the asymmetric aldol reaction between representative ketones with various aromatic aldehydes under solvent-free conditions in a ball mill.In particular, the methyl ester of (S)-proline-(S)-tryptophan, (S,S)-1c, proved to be an efficient organocatalyst, and the aldol reaction proceeded with good chemical ...

Natural low-molecular mass organic compounds with ... - PNAS

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

ball milling asymmetric organocatalysis

Asymmetric organocatalysis in a ball mill TIB AVPortal. 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 oratory the ball milling device is shown, and reaction details are revealed Finally, future ...

Organocatalyst Efficiency in the Michael Additions of ...

Ball milling has also been successfully applied to organocatalytic reactions, in particular to the aldol reaction. 14 Wang described the first Michael addition under solvent‐free conditions in a vibrating ball mill. 15 Mechanical activation in the ball mill enabled the use of milder bases and led to improved chemical yields and shorter ...

Reacciones asimétricas 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. …

Asymmetric Catalysis - Home ICM

[23] Hernández 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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