99662-36-9

Upstream product

• 1121-60-4 pyridine-2-carbaldehyde 
• 67-64-1 acetone 
• 1439-36-7 1-triphenylphosphoranylidene-2-propanone 
• 863677-33-2 2-pyridinylbenzaldehyde 
• 123-42-2 4-Hydroxy-4-methyl-2-pentanone 
• 300804-02-8 (E)-4-(pyridin-2-yl)but-3-en-2-ol 
• 56-23-5 tetrachloromethane 
• 7732-18-5 water 
• 6954-28-5 methyl 3-oxo-2-(pyridin-2-ylmethylene)butanoate 
• 105902-82-7 2-(hydroxy-[2]pyridyl-methyl)-acetoacetic acid ethyl ester 

Relevant academic research and scientific papers

Rate dependence on inductive and resonance effects for the organocatalyzed enantioselective conjugate addition of alkenyl and alkynyl boronic acids to β-indolyl enones and β-pyrrolyl enones

Two key factors bear on reaction rates for the conjugate addition of alkenyl boronic acids to heteroaryl-appended enones: the proximity of inductively electron-withdrawing heteroatoms to the site of bond formation and the resonance contribution of available heteroatom lone pairs to stabilize the developing positive charge at the enone β-position. For the former, the closer the heteroatom is to the enone β-carbon, the faster the reaction. For the latter, greater resonance stabilization of the benzylic cationic charge accelerates the reaction. Thus, reaction rates are increased by the closer proximity of inductive electron-withdrawing elements, but if resonance effects are involved, then increased rates are observed with electron-donating ability. Evidence for these trends in isomeric substrates is presented, and the application of these insights has allowed for reaction conditions that provide improved reactivity with previously problematic substrates.

Sequential Two-Step Stereoselective Amination of Allylic Alcohols through the Combination of Laccases and Amine Transaminases

A sequential two-step chemoenzymatic methodology for the stereoselective synthesis of (3E)-4-(het)arylbut-3-en-2-amines in a highly selective manner and under mild reaction conditions is described. The approach consists of oxidation of the corresponding racemic alcohol precursors by the use of a catalytic system made up of the laccase from Trametes versicolor and the oxy-radical TEMPO, followed by the asymmetric reductive bio-transamination of the corresponding ketone intermediates. Optimisation of the oxidation reaction, exhaustive amine transaminase screening for the bio-transaminations and the compatibility of the two enzymatic reactions were studied in depth in search of a design of a compatible sequential cascade. This synthetic strategy was successful and the combinations of enzymes displayed a broad substrate scope, with 16 chiral amines being obtained in moderate to good isolated yields (29–75 %) and with excellent enantiomeric excess values (94 to >99 %). Interestingly, both amine enantiomers can be achieved, depending on the selectivity of the amine transaminase employed in the system.

One-pot two-step chemoenzymatic deracemization of allylic alcohols using laccases and alcohol dehydrogenases

A series of enantioenriched (hetero)aromatic secondary allylic alcohols has been synthesized through deracemization of the corresponding racemic mixtures combining a non-selective chemoenzymatic oxidation (laccase from Trametes versicolor and oxy-radical TEMPO) and a stereoselective biocatalyzed reduction (lyophilized cells of E. coli overexpressing an alcohol dehydrogenase, ADH). Both steps were performed in aqueous medium under very mild reaction conditions. After optimization, a sequential one-pot two-step protocol was set up, obtaining the corresponding chiral alcohols in moderate to high conversions (48–95%) and enantiomeric excess (65->99% ee). Depending on the ADH stereopreference, both antipodes from these valuable chiral synthons could be prepared, even at preparative scale (119?178 mg), in a straightforward manner.

Boehmite - An efficient and recyclable acid-base bifunctional catalyst for aldol condensation reaction

In this work boehmite was used as an acid-base bifunctional catalyst for aldol condensation reactions of aromatic aldehydes and ketones. The catalyst was prepared by simple sol-gel method using Al(NO3)3 · 9H2O and NH4OH as precursors. The catalyst has been characterized by X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), UV-visible spectroscopy (DRS), BET surface area analyses. Boehmite is successfully applied as catalyst for the condensation reaction between 4-nitrobenzaldehyde and acetone as a model substrate giving α,β-unsaturated ketones without any side product. The scope of the reaction is extended for various substituted aldehydes. A probable mechanism has been suggested to explain the cooperative behavior of the acidic and basic sites. The catalyst is environmentally friendly and easily recovered from the reaction mixture. Also the catalyst is reusable up to 3 catalytic cycles.

A method of preparing alpha,beta-unsaturated ketones

The invention relates to a method of preparing alpha,beta-unsaturated ketones. The method is characterized by comprising steps of (1) adding a copper catalyst and an alkali into a reaction tube, adding a liquid mixture of a solvent and reactants which are a beta-hydroxy ketone and an aromatic aldehyde under nitrogen protection into the reaction tube and reacting the mixture; (2) performing filtration, extraction, drying, and low-pressure solvent removing after the reaction is finished to obtain an alpha,beta-unsaturated ketone crude product; and (3) performing separation and purification to obtain an alpha,beta-unsaturated ketone product. A copper enolate is generated in situ through a retrograde aldol condensation reaction and is further subjected to aldol condensation with the aromatic aldehyde to obtain the final product. The beta-hydroxy ketone and the aromatic aldehyde are injected through injectors under nitrogen protection, and the reaction is performed under stirring in an oil bath pot having a temperature of 25-120 DEG C for 3-8 h. The method has characteristics of mild conditions, simple operation, easily available raw materials, and environment protection and is hopped to be widely applied in the fine chemical synthesis fields such as medicine intermediates, perfume and pesticides.

Method for preparing alpha and beta-unsaturated ketone

The invention provides a method for preparing alpha and beta-unsaturated ketone. The method includes that L-proline is used as a catalyst, secondary amine is used as a cocatalyst, and the alpha and beta-unsaturated ketone can be directly synthesized in alcohol or ketone solution by means of aldol condensation under neutral conditions at one step. Compared with the traditional method, the method has the advantages that raw materials are easily available, the method is low in cost and is environmental friendly, reaction conditions are mild, solvents are clean and environmental friendly, equipment can be protected against corrosion under the neutral conditions, the catalyst is high in acid resistance, and the method is applicable to industrial production.

Copper-catalyzed retro-aldol reaction of β-hydroxy ketones or nitriles with aldehydes: Chemo- and stereoselective access to (E)-enones and (E)-acrylonitriles

A copper-catalyzed transfer aldol type reaction of β-hydroxy ketones or nitriles with aldehydes is reported, which enables chemo- and stereoselective access to (E)-α,β-unsaturated ketones and (E)-acrylonitriles. A key step of the in situ copper(i)-promoted retro-aldol reaction of β-hydroxy ketones or nitriles is proposed to generate a reactive Cu(i) enolate or cyanomethyl intermediate, which undergoes ensuing aldol condensation with aldehydes to deliver the products. This reaction uses 1.2 mol% Cu(IPr)Cl (IPr denotes 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) as the catalyst in the presence of 6.0 mol% NaOtBu cocatalyst at room temperature or 70 °C. A range of aryl and heteroaryl aldehydes as well as acrylaldehydes are compatible with many useful functional groups being tolerated. Under the mild and weakly basic conditions, competitive Cannizzaro-type reaction of benzaldehydes and side reactions of base-sensitive functional groups can be effectively suppressed, which show synthetic advantages of this reaction compared to classic aldol reactions. The synthetic potential of this reaction is further demonstrated by the one-step synthesis of biologically active quinolines and 1,8-naphthyridine in excellent yields (up to 91%). Finally, a full catalytic cycle for this reaction has been constructed using DFT computational studies in the context of a retro-aldol/aldol two-stage mechanism. A rather flat reaction energy profile is found indicating that both stages are kinetically facile, which is consistent with the mild reaction conditions.

A general method for the enantioselective synthesis of α-chiral heterocycles

The enantioselective formation of stereocenters proximal to unprotected heterocycles has been accomplished. Thus, vinyl boronic acids are added to heterocycle-appended enones via a modified-BINOL catalyst. Catalyst design was key to enable a general reaction. High yields and useful er's are observed for a host of common heteroaryls.

Chitosan hydrogel: A green and recyclable biopolymer catalyst for aldol and Knoevenagel reactions

Chitosan hydrogel is efficiently utilized as an organocatalyst for aldol and Knoevenagel reactions, providing the products in high yields with a high chemoselectivity under biphasic conditions. The catalyst was recovered by simple filtration and reused several times without significant loss of activity. the Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2006.

Synthesis and Antimalarial Properties of 1-Imino Derivatives of 7-Chloro-3-substituted-3,4-dihydro-1,9(2H,10H)-acridinediones and Related Structures

To improve upon the activity and properties of the 3-aryl-7-chloro-3,4-dihydro-1,9(2H,10H)-acridinediones, a variety of 1-imino derivatives (3) were prepared and shown to be highly active antimalarial agents in both rodents and primates.Among structural modifications prepared, including N10-alkyl and C2-substituted analogs, removal of the C9 oxygen, and introduction of an imino side chain at C9, the imines of the N10-H acridinediones were the most active compounds obtained.The imino derivative of7-chloro-3-(2,4-dichlorophenyl)-3,4-dihydro-1,9(2H,10H)-acridinedione (9aa) proved to be highly active in advanced studies in primates.