efficient ball mill procedure in the green asymmetric aldol reaction
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Synthesis and Reactions of Hydroxyphosphonates
environmentally friendly approaches green activation methods such as microwave MW irradiation 30 31 and grinding 32 33 were also employed in the synthesis of hydroxyphosphonates 1 According to a MW assisted procedure the reaction of benzaldehydes and
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Organocatalysis in aqueous media Nature Reviews
In terms of aqueous reactions catalysts that activate a carbonyl substrate to form an enamine and iminium typically as part of an overall asymmetric aldol reaction have received the most
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Click Chemistry
Click Chemistry Azide Alkyne Cycloaddition Click Chemistry is a term that was introduced by K B Sharpless in 2001 to describe reactions that are high yielding wide in scope create only byproducts that can be removed without chromatography are stereospecific simple to perform and can be conducted in easily removable or benign solvents.
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Redox reactions of small organic molecules using ball
Mixing solid reactants in a ball mill is a promising means of avoiding the copious solvent waste associated with most chemical syntheses et al now report that adding a piezoelectric catalyst to the mix can promote bond formation through apparent electron transfer cycles see the Perspective by Xia and Wang Specifically barium titanate activates aryl diazonium salts toward
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A Review on Solvent free Methods in Organic Synthesis
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 In this review we have discussed most recent literature survey on applications of solvent free techniques in organic synthesis which would offer a new opportunity to a
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Ball Milling Towards Green Synthesis Applications
Chapter 1 Carbon Heteroatom Bond Forming Reactions and Heterocycle Synthesis under Ball Milling by Brindaban C Ranu Tanmay Chatterjee and Nirmalya Mukherjee Indian Association for the Cultivation of Science India covers carbon–heteroatom C–N C–O C–S C–Cl C–Br bond formation and synthesis of heterocycles under ball
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Substituted arene synthesis by alkylation or arylation
L T Ball M Green G C Lloyd Jones C A Russel Org Lett 2010 12 A well defined cationic Ru H complex catalyzes the dehydrative C H alkylation reaction of phenols with alcohols to form ortho substituted phenol products The reaction with diols delivers benzofuran derivatives via dehydrative C H alkenylation and annulation
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A green look at the aldol reactionGreen Chemistry RSC
Introduction The aldol reaction is one of the most powerful and best known C–C forming synthetic reactions universally present in basic and advanced organic chemistry texts and amply reviewed in organic synthetic books and series 1–4 The reaction has industrial relevance either in bulk production or in the fine chemical and pharmaceutical industry 5 The aldol reaction has a particular
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Development and Application of Efficient Ag‐based
The selective hydrogenation of nitro groups is an important reaction as it has found many applications in industry and academia since the first industrial application was reported by Béchamp more than 150 years ago 16 Starting from this non catalytic approach the use of hydrogen as reducing agent rapidly became the method of choice Numerous homogenous as well as heterogenous metal
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A more sustainable and efficient access to IMesHCl and
balls agitated at 500 rpm in a planetary ball mill pbm furnished the corresponding DAD in quantitative yield This was confirmed by IR analysis of the reaction mixture and by the characteristic yellow colour of the reaction mixture As perfect stoichiometry of reagents was used and full conversion was obtained in the
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PDF e EROS Encyclopedia of Reagents for Organic
The catalytic complex obtained by reaction with titanium tetra isopropoxide gave the O TMS cyanohydrin with 47 yield and 33 ee Better results up to
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Supporting Information for
Typical experimental procedure for the solvent free aldol reaction performed in the ball mill A ball mill vessel was charged with cyclohexanone 67 mL 0.65 mmol p nitrobenzaldehyde 89 mg 0.59 mmol 1b 40 mg 0.059 mmol and 2 balls Stirring was started in a grinding bowl using the ball mill with a frecuency of 30 s 1.
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A Simple and Green Protocol for 2H Indazolo 2 1 b
A robust facile and solvent free route for the three component synthesis of 2 H indazolo 2 1 b phthalazine triones in the presence of a catalytic amount of p toluene sulfonic acid utilizing grinding has been developed Short reaction time simple operation and high yields are the advantages of this protocol.
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Mechanochemistry assisted asymmetric organocatalysis
Scheme 4 Asymmetric aldol reaction assisted by ball milling catalysed by dipeptides A with III and B with IV The methyl ester of S proline S tryptophan IV was shown to be an efficient organocatalyst for asymmetric aldol reactions of ketones with aromatic aldehydes in the presence of water by using HSBM Scheme€4 37 .
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Homochiral bifunctional L ‐prolinamide‐ and L‐ bis
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
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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 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
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X MOL
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.
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10.1016/j.tet.2011.06.042 10.1016/j.tet.2011 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
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green aldol ndensation by ball mill method
Efficient Ball Mill Procedure In The Green Asymmetric Aldol Reaction the organocatalytic activity of the methyl ester of s proline s phenylalanine s s 2 in the asymmetric aldol reaction between cyclohexanone and acetone with various aromatic aldehydes under solvent free conditions in a ball mill has been evaluated dipeptide s s 2
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Highly Diastereo‐ and Enantioselective Direct Aldol
List Lerner and Barbas discovered the proline‐mediated aldol reaction in 2000 13 Since then many organocatalysts have been developed for several asymmetric reactions 6 14 Proline is capable of catalyzing the direct aldol reaction in polar organic solvents such as DMSO and DMF 13 15 16 Recently Bolm and co‐workers reported that
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Aldol condensation Research PapersAcademia.edu
Efficient ball mill procedure in the green asymmetric aldol reaction organocatalyzed by S proline containing dipeptides in the presence of water Save to Library Download
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Solvent free enantioselective organocatalyzed aldol
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
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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 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
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Influence of the milling parameters on the mechanical
1 Influence of the milling parameters on the mechanical work intensity in planetary mills F J Gotor 1 M Achimovicova 2 C Real 1 and P Balaz 2 1Instituto de Ciencia de Materiales de Sevilla CSIC US Américo Vespucio 49 41092 Sevilla SPAIN 2Institute o f Geotechnics Slovak Academy of Sciences Watsonova 45 043 53 Košice
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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
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Publications 1994 PresentStanford University
Present 1994 1000 Trost B M Huang Z Catalytic 3 2 Palladium Aminoallyl Cycloaddition with Conjugated Dienes Angew
Get PriceChemInform 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.
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Recent Strategies in the Synthesis of Spiroindole and
After the aldol procedure in a one pot process substrate 110 could be readily involved with three equivalents of NCS and converted to dearomatizated product 111 in 76 efficiency and 94 ee Furthermore high diastereoselectivity was acquired due to the steric strain of
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Natural low molecular mass organic compounds with
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.
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Mechanochemical 1 1 Carbonyldiimidazole Mediated
Table 1 Reaction Scope for the One Pot/Two Step Preparation of N O Disubstituted Carbamates in a Vibrational Ball Milla b aTypical procedure using 5 mL stainless steel jar 2 stainless steel balls 5 mm diameter in a vibrational ball mill at 30 Hz step 1 alcohol 0.58
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Organocatalytic solvent free hydrogen bonding mediated
An efficient solvent free protocol for asymmetric Michael additions of α nitrocyclohexanone to nitroalkenes using thiourea derivatives as hydrogen bonding catalysts has been developed By performing the organocatalytic reactions in a planetary ball mill
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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 DOI 10.1016/j.tet.2011.06.042.
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A highly efficient asymmetric organocatalytic aldol
Anti aldol products with up to >99 enantiomeric excess ee have been obtained by proline catalysis in excellent yields under experimentally simple solvent free conditions Efficient mixing of all the components is accomplished by applying a mechanochemical technique ball milling The catalysis is air and moisture tolerant and can be performed with non purified starting materials.
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