324535-32-2

Upstream product

• 108-94-1 cyclohexanone 
• 78-84-2 isobutyraldehyde 

Downstream Products

• 1006707-04-5 benzoic acid 2-methyl-1-(2-oxocyclohexyl)propyl ester 

Relevant academic research and scientific papers

Proline dipeptides containing fluorine moieties as oganocatalysts for the asymmetric aldol reaction

A series of dipeptide analogues consisting of proline, phenylalanine and aniline- or phenol-fluorine derivatives were synthesized. Their catalytic ability was evaluated in the intermolecular asymmetric aldol reaction, both in organic and aqueous media. Aniline-fluorine derivatives proved to be superior and the best results were obtained, when 2-CF3 aniline was employed. A diverse substrate scope consisting of both aromatic and aliphatic aldehydes, as well as different ketones was demonstrated, where aromatic aldehydes afforded products in high yields (up to 100%) with excellent diastereo- (up to 95:5) and enantioselectivities (up to 97%), whereas the aliphatic aldehydes afforded also excellent selectivities, but relatively low yield. A simple addition of fluorine to a dipeptide analogue affords organocatalysts with new interesting properties that can catalyze the aldol reaction more efficiently.

Reversal of enantioselectivity in aldol reaction: New data on proline/λ-alumina organic-inorganic hybrid catalysts

We report new results on the aldol reactions between aldehydes of three different types (aromatic, aliphatic and cycloaliphatic) and acetone/cycloalkanones as reaction partners, driven by organic-inorganic hybrid catalyst Pro/λ-Al2O3. In contrast to the homogeneous liquidphase reaction, over Pro/λ-Al2O 3reversal of the enantioselection in up to 20-40 % ee depending on the structure of the aldehyde was observed in reactions of acetone. Reversal of the ee in the presence of c-Al2O3cannot be generalized, as it has only been observed for acetone among the ketones studied by us. It was proven using methods of a great variety such as ultrasonic irradiation, reuse measurements on used catalyst and the filtrate of the first reaction, measurements on the L-Pro-L-Pro(OH) dipeptide, studies using mixtures of L-Pro and D-Pro that the organic-inorganic hybrid catalyst Pro/λ-Al 2O3formed in situ is responsible for reversal of the ee. In the reactions of cycloalkanones there is presumably competition between the liquid-phase and the surface reaction over Pro/ c-Al2O 3with preference for the former. Based on these results a surface reaction pathway was proposed. Although, the ees obtained under heterogeneous catalytic conditions are low, further studies may lead to application of this unusual phenomenon for obtaining chiral heterogeneous catalysts suitable for the preparation of the desired enantiomer of a chiral compound using the same chiral source. Springer Science+Business Media New York 2013.

Unusual enantioselectivities in heterogeneous organocatalyzed reactions: Reversal of direction using proline di- versus tri-peptides in the aldol addition

The heterogeneous asymmetric direct aldol reactions between aldehydes (2-nitrobenzaldehyde, 2-methylpropanal) and ketones (acetone, cyclohexanone) in the presence of polystyrene (PS) resin supported di- and tripeptides were studied under otherwise identic

L-proline/CoCl2-catalyzed highly diastereo- and enantioselective direct aldol reactions

The CoCl2/L-proline (1:2) system was found to be an excellent catalyst for direct aldol reactions. Excellent yields (up to 93 %) and a significant improvement in diastereoselectivity (anti/syn up to 45:1) as well as enantioselectivity (up to mo

The ion tag strategy as a route to highly efficient organocatalysts for the direct asymmetric aldol reaction

The installation of an imidazolium tag via acetate connection to the C-4 of cis-4-hydroxy-l-proline provides a highly efficient catalyst for the direct asymmetric aldol reaction, that works in a remarkably low catalyst loading (0.1 mol%) affording TONs up

Direct asymmetric aldol reaction catalyzed by an imidazolium-tagged trans-4-hydroxy-l-proline under aqueous biphasic conditions

Imidazolium-tagged trans-4-hydroxy-L-proline, recently reported by us as an efficient catalyst for the asymmetric cross-aldol reaction in [bmim][Tf 2N], gives much better results in terms of catalytic activity and stereochemical performance und

A modular approach to catalyst hydrophobicity for an asymmetric aldol reaction in a biphasic aqueous environment

Catalyst 5, an ion pair consisting of a hydrophilic cation and a lipophilic anion, fulfils the solubility requirements needed to couple efficiency (enantioselectivities and anti-diastereoselectivities up to ≥99%) and catalyst recyclability in asymmetric aldol reactions under aqueous biphasic conditions.

Enantioselective radical reactions: Stereoselective aldol synthesis from cyclic ketones

(Chemical Equation Presented) Radicalized aldols: Enones with a fixed s-cis geometry can undergo enantioselective radical reactions. The synthesis of aldol products derived from cyclic ketones in excellent yields and enantioselectivity demonstrates that s-cis-enones are excellent substrates for radical reactions. A tentative model to explain the stereochemical outcome of the reaction consists of nucleophilic radical addition to the si face (see picture).

Highly diastereo- and enantioselective direct aldol reactions of aldehydes and ketones catalyzed by siloxyproline in the presence of water

Proline-based organocatalysts have been developed for a highly enantioselective, direct aldol reaction of aldehydes and ketones in the presence of water. While several surfactant-proline combined catalysts have proved effective, proline derivatives with a hydrophobic moiety such as rraw-siloxy-L-proline and cis-siloxy-D-proline, both of which are easily prepared from the same commercially available 4-hydroxy-L-proline. have been found to be the most effective organocatalysts examined in this study, affording the aldol product with excellent diastereo- and enantioselectivities, these two catalysts generating opposite enantiomers. Water affects the selectivity, and poor results are obtained under neat reaction conditions or in dry organic solvents. More than three equivalents of water are required for the best diastereo- and enantioselectivities. while three equivalents is the recommended amount from a synthetic point of view. The reaction proceeds in the organic phase, and also proceeds in the presence of a large amount of water. The large-scale preparation of aldols with the minimal use of an organic solvent, including in the purification step. is described.

Highly diastereo- and enantioselective direct aldol reactions of cycloketones with aldehydes catalyzed by a trans-4-tert-butyldimethylsiloxy-l-proline amide

An organocatalyst derived from trans-4-hydroxy-l-proline and (1S,2S)-1,2-diphenyl-2-aminoethanol catalyzes the direct aldol reactions of cycloketones with a wide scope of aldehydes in high yields and with excellent diastereoselectivities of up to >99:1 an