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Upstream product

• 21461-46-1 (E)-2-(2-nitrovinyl)naphthalene 
• 83976-41-4 (S)-2-methoxymethylpyrrolidine cyclohexanone enamine 
• 108-94-1 cyclohexanone 
• 37629-37-1 2-(2-nitrovinyl)naphthalene 

Relevant academic research and scientific papers

Remarkable Effect of tert-Amine Additives in the Asymmetric Direct Michael Reaction of Ketones with β-Arylnitroethenes Catalyzed by an L-Hydroxyproline-Based Amino Tf-Amide Organocatalyst

A catalytic asymmetric direct Michael reaction of ketones with trans-β-arylnitroethenes can be achieved under the influence of optically pure L-hydroxyproline-based secondary-amino aromatic Tf-amide organocatalyst. The effect of the trialkylamine base additive such as diethylmethylamine is of paramount importance to accomplish high reactivity and enantioselectivity in this asymmetric Michael reaction.

Pyrrolidine-Oxadiazolone Conjugates as Organocatalysts in Asymmetric Michael Reaction

Pyrrolidine-oxadiazolone based organocatalysts are envisaged, synthesized, and utilized for asymmetric Michael reactions. Results of the investigations suggest that some of the catalysts are indeed efficient for stereoselective 1,4-conjugated Michael additions (dr: >97:3, ee up to 99%) in high chemical yields (up to 97%) often in short reaction time. As an extension, one enantiopure Michael adduct has been utilized to synthesize optically active octahydroindole.

Solvent free, fast and asymmetric Michael additions of ketones to nitroolefins using chiral pyrrolidine–pyridone conjugate bases as organocatalysts

New chiral organocatalysts are envisaged based on a pyrrolidine–pyridone conjugate and synthesized from commercially available proline employing standard protocols. These catalysts were found to be useful for asymmetric Michael additions of ketones to nitroolefins to afford the desired products in very good yields (up to 98%) with excellent diastereo- and enantioselectivities (>97:3 syn/anti and up to 98% ee) in very short reaction time compared with the existing reports.

Pyrrolidine-HOBt: an oxytriazole catalyst for the enantioselective Michael addition of cyclohexanone to nitroolefins in water

A new analogue of the proline derived organocatalyst ‘pyrrolidine-HOBt’ has been designed and synthesized from L-prolinol and hydroxybenzotriazole (HOBt) employing a simple reaction protocol. The catalyst was found to be effective in promoting the asymmet

Biomimetic asymmetric Michael addition reactions in water catalyzed by amino-containing β-cyclodextrin derivatives

Nine β-cyclodextrin derivatives containing an amino group were synthesized via nucleophilic substitution from mono(6-O-p-tolylsulfonyl)-β-cyclodextrin and used in asymmetric biomimetic Michael addition reactions in water at room temperature. The mechanism responsible for the moderate activity and enantioselectivity of the β-cyclodextrin derivatives was explored using nuclear magnetic resonance spectroscopy, namely 2D 1H rotating-frame overhauser effect spectroscopy (ROESY), ultraviolet absorption spectroscopy, and quantum chemical calculations, which provide a useful technique for investigating the formation of inclusion complexes. The effects of the pH of the reaction medium, the β-cyclodextrin derivative dosage, the structure of the modifying amino group, and various substrates on the yield and enantioselectivity were investigated. The results indicated that these factors had an important effect on the enantiomeric excess (ee) in the reaction system. Experiments using a competitor for inclusion complex formation showed that a hydrophobic cavity is necessary for enantioselective Michael addition. A comparison of the reactions using 4-nitro-β-nitrostyrene and 2-nitro-β-nitrostyrene showed that steric hindrance improved the enantioselectivity. This was verified by the optimized geometries obtained from quantum chemical calculations. An ee of 71% was obtained in the asymmetric Michael addition of cyclohexanone and 2-nitro-β-nitrostyrene, using (S)-2-aminomethylpyrrolidine-modified β-CD as the catalyst, in an aqueous buffer solution, i.e., CH3COONa-HCl (pH 7.5).

4-Fluoro and 4-hydroxy pyrrolidine-thioxotetrahydropyrimidinones: Organocatalysts for green asymmetric transformations in brine

The synthesis of both trans- and cis-diastereomers of pyrrolidinine-thioxotetrahydropyrimidinone bearing either a fluorine or a hydroxyl group was accomplished. The new compounds were tested for their catalytic properties in a variety of asymmetric organic transformations and compared with the first generation catalyst. It was found that the new catalysts could efficiently catalyze the reactions in brine, without the use of organic solvent, and by employing an almost stoichiometric amount of reagents. Thus, the products were isolated by simple extractions, avoiding the use of chromatography in excellent yields, diastereoselectivities, and enantioselectivities.

Densely substituted l -proline esters as catalysts for asymmetric michael additions of ketones to nitroalkenes

Homochiral methyl 4-aminopyrrolidine-2-carboxylates are readily obtained by means of asymmetric (3 + 2) cycloadditions between azomethine ylides and nitroalkenes, followed by catalytic hydrogenation of the intermediate 4-nitro cycloadducts. These 4-aminopyrrolidine-2-carboxylate esters belong to the l-series of natural amino acids and catalyze asymmetric Michael additions of ketones to nitroalkenes. However, the enantioselectivity observed with these novel unnatural organocatalysts is opposite to that obtained with l-proline. Since both 4-nitro and 4-amino l-proline esters are efficient organocatalysts of aldol reactions, these results permit to modulate asymmetric quimioselective aldol and conjugate addition reactions.

Chiral amine catalyzed enantio- and diastereoselective Michael reaction in brine

Simple pyrrolidine-based chiral amines were synthesized and used for the Michael addition of different ketones to a variety of nitro-olefins in brine. The effect of different surfactants and acids on the yields and stereochemical outcome of the Michael ad

4-aminothioureaprolinal dithioacetal as a catalyst for highly enantioselective michael additions of ketones and aldehydes to nitroolefins

4-Aminothioureaprolinal dithioacetal 4a is a highly efficient catalyst for the asymmetric Michael addition of ketones and aldehydes to nitroolefins requiring only 3 mol-% catalyst loading. The reactions proceeded smoothly and gave syn selective adducts with excellent yields (up to 98a% yield), diastereoselectivity (up to >99:1adr), and enantioselectivity (up to 99a%aee) under solvent free conditions at room temperature. This extremely simple and practical procedure increases the attractiveness of this reaction. 4-Aminothioureaprolinal dithioacetal 4a is a highly efficient catalyst for asymmetric Michael additions of ketones and aldehydes to nitroolefins. Using only 3 mol-% catalyst loading, reactions proceededsmoothly and gave syn selective adducts in excellent yields with excellent diastereoselectivity and enantioselectivity under solvent-free conditions at room temperature.

Novel pyrrolidine-thiohydantoins/thioxotetrahydropyrimidinones as highly effective catalysts for the asymmetric Michael addition

The synthesis of novel organocatalysts consisting of a pyrrolidine moiety and a thiohydantoin or a thioxotetrahydropyrimidinone ring is described. The compound combining the pyrrolidine with the thioxotetrahydropyrimidinone was found to be a highly effect