Three 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 ...
A Highly Efficient Solvent-Free Asymmetric Direct Aldol Reaction Organocatalyzed by Recoverable (s)-Binam-L-Prolinamides. ... 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 enantioselectivities ...
(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
Request PDF | Ball-milling: An efficient and green approach for asymmetric organic synthesis | Mechanochemical approach in organic synthesis is of growing …
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].
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
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.
Design of potential peptide catalysts and synthesis of Juaristi catalyst 1n for the neat aldol reaction under ball milling conditions (iBBCl= isobutyl chloroformate, NMM= 4‐methylmorpholine). Being inspired by Type I aldolases, it is not surprising that the aldol reaction was the first transformation on which peptide organocatalysts were tested.
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 …
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).
Ball Milling An efficient and ecologically friendly synthetic approach ‐‐‐ Jackie Ding . Ball milling – solvent free approach Application in organic synthesis Conclusion Content 2 . The 12 Principles of Green Chemistry ... Planetary Ball Mill PM 400 Feed material: soft, hard,
(3) J.G. Hernández 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).
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
Design of potential peptide catalysts and synthesis of Juaristi catalyst 1n for the neat aldol reaction under ball milling conditions (iBBCl= isobutyl chloroformate, NMM= 4-methylmorpholine). Being inspired by Type I aldolases, it is not surprising that the aldol reaction was the first transformation on which peptide organocatalysts were tested.
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 ...
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.
ChemInform Abstract: Efficient Ball-Mill Procedure in the ′Green′ Asymmetric Aldol Reaction Organocatalyzed by (S)-Proline-Containing Dipeptides in the Presence of Water.
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), …
Ball Milling An efficient and ecologically friendly synthetic approach ‐‐‐ Jackie Ding . Ball milling – solvent free approach Application in organic synthesis Conclusion Content 2 . The 12 Principles of Green Chemistry ... Planetary Ball Mill PM 400 Feed material: soft, hard,
Efficient ball-mill procedure in the 'green' asymmetric aldol reaction organocatalyzed by (S)-proline-containing dipeptides in the presence of water José …
Request PDF | A Highly Efficient Asymmetric Organocatalytic Aldol Reaction in a Ball Mill | Anti-aldol products with up to >99 % enantiomeric excess (ee) have been obtained by …
132. Hernández 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.
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 ...
Indeed, in aldol reaction catalyzed by proline resi- obtained in high yields (up to 94%) and good enantioselectivities dues embedded in a hydrophobic environment, water has dem- (up to 97% ee).17a In addition, Li and co-workers examined di- onstrated to play an important role in organocatalytic reactions peptide (1c-OH) in the asymmetric aldol ...
[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 water,Tetrahedron, 2011, 67, 6953-6959.
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 …
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 …
J. G. Hernández and E. Juaristi, Efficient Ball-Mill Procedure in the "green" Asymmetric Aldol Reaction Organocatalyzed by (S)-Proline-Containing Dipeptides in the Presence of Water, Tetrahedron, 2011, 10.1016/j.tet.2011.06.042 67, 6953 —6959 CrossRef.
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 ...
An efficient, solvent-free ball-milling protocol for the asymmetric aldol reaction between cyclohexanone and cyclopentanone with various aromatic aldehydes using a novel series of (S)-proline-containing dipeptides and thiodipeptides 1a–f as organocatalysts is reported.In general, (S)-proline-containing thiodipeptides proved to be better organocatalysts relative to their …