53940-08-2Relevant academic research and scientific papers
Lewis acid catalysis of a Diels-Alder reaction in water
Otto, Sijbren,Bertoncin, Federica,Engberts, Jan B. F. N.
, p. 7702 - 7707 (1996)
Here we report the first detailed study of a Diels-Alder (DA) reaction that is catalyzed by Lewis acids in water. The effect of Co2+, Ni2+, Cu2+ and Zn2+ ions as Lewis acid catalysts on the rate and endo-exo selectivity of the DA reaction between the bidentate dienophiles 3-phenyl-1-(2-pyridyl)-2-propen-1-ones (1a-e) and cyclopentadiene (2) in water has been studied. Relative to the uncatalyzed reaction in acetonitrile, catalysis by 0.010 M Cu(NO3)2 in water accelerates the reaction by a factor of 79300. The kinetics of the catalyzed reaction were analyzed in terms of equilibrium constants for complexation of the Lewis acid with 1a-e and rate constants for the reaction of the resulting complexes with 2. The rate enhancement imposed upon the uncatalyzed DA reaction of substrates 1 with 2 by water is much more pronounced than that for the catalyzed reaction. The increase of the endo-exo selectivity induced by water in the uncatalyzed process is completely absent for the Lewis acid catalyzed reaction. The modest solvent and substituent effects observed for the catalyzed reaction indicate that the change in charge separation during the activation process is not larger than the corresponding change for the uncatalyzed reaction.
Synthesis, biological activities of chalcones and novel 4-acetylpyridine oximes, molecular docking of the synthesized products as acetylcholinesterase ligands
Behr, Jean-Bernard,Benazzouz-Touami, Amina,Machado-Rodrigues, Carine,Makhloufi-Chebli, Malika,Ould Lamara, Kamilia,Robert, Anthony,Terrachet-Bouaziz, Souhila
, (2021/12/22)
Heterocyclic chalcones were synthesized by reaction of 4-acetylpyridine with the corresponding aromatic aldehydes under Claisen Schmidt conditions. These chalcones were used as starting material for the synthesis of oximes in the presence of hydroxylamine
One-Pot Catalytic Enantioselective Synthesis of 2-Pyrazolines
Thomson, Connor J.,Barber, David M.,Dixon, Darren J.
supporting information, p. 2469 - 2473 (2019/02/01)
A scalable, one-pot, enantioselective catalytic synthesis of 2-pyrazolines from beta-substituted enones and hydrazines is described. Pivoting on a two-stage catalytic Michael addition/condensation strategy, the use of an aldehyde to generate a suitable hydrazone derivative of the hydrazine was found to be key for curtailing background reactivity and tuning the catalyst-controlled enantioselectivity. The new synthetic method is easy to perform, uses a new and readily prepared cinchona-derived bifunctional catalyst, is broad in scope, and tolerates a range of functionalities with high enantioselectivity (up to >99:1 e.r.). The significant scalability of this methodology was demonstrated with the synthesis of more than 80 grams of a pyrazoline product with 89 % catalyst recovery.
Methylene-bridged bis(imidazoline)-derived 2-oxopyrimidinium salts as catalysts for asymmetric Michael reactions
Sheshenev, Andrey E.,Boltukhina, Ekaterina V.,White, Andrew J. P.,Hii, King Kuok
supporting information, p. 6988 - 6991 (2013/07/25)
In nothing flat: The title salts, having planar nitrogen centers, were utilized successfully as phase-transfer catalysts for asymmetric Michael reactions of tert-butyl glycinate benzophenone Schiff base with vinyl ketone and chalcone derivatives, thus providing excellent levels of diastereo- and enantiocontrol (see scheme). Copyright
Preparation of some heterocyclic enones and ynones by isomerisation of the propargylic alcohols
Erenler, Ramazan,Uno, Masaharu,Goud, Thirumani Venkateshwar,Biellmanna, Jean-Francois
experimental part, p. 459 - 464 (2010/01/16)
The propargylic alcohols were synthesised by treatment of aldehydes with substituted acetylenes. The conversion of propargylic alcohols to propynones and propenones takes place with pyridine hydrochloride in methanol at room temperature. In presence of pyridinium triflate and p-toluenesulfonate the propynone was the only product isolated in the isomerisation of alcohol. The silylated propenone undergoes with cyclopentadiene a Diels-Alder cycloaddition to give ketone whose skeleton is related to that of quinine.
A simple, modular synthesis of substituted pyridines
Liu, Songbai,Liebeskind, Lanny S.
, p. 6918 - 6919 (2008/09/21)
A simple, modular method to prepare highly substituted pyridines is disclosed. The method employs a cascade reaction comprising (1) a novel N-iminative, Cu-catalyzed cross-coupling of alkenylboronic acids at the N-O bond of α,β-unsaturated ketoxime O-pentafluorobenzoates, (2) electrocyclization of the resulting 3-azatriene, and (3) air oxidation affording highly substituted pyridines in moderate to excellent isolated yields (43-91%). Starting materials are readily available, and functional group tolerance is very good. Copyright
Synthesis of substituted 1-(2-arylvinyl)-2-azolyl-1-pyridylethanols-1
Zakharychev,Kuzenkov
, p. 989 - 995 (2008/09/19)
A series of new 1-(2-arylvinyl)-2-azolyl-1-pyridylethanols-1 has been obtained with various positions of the nitrogen atom in the pyridine fragment and with substituents in the benzene ring, by the reaction of (2-arylvinyloxiran-2-yl)pyridines with triazole and imidazole, for agrochemical screening. The compounds mentioned displayed high fungicidal activity.
Synthesis of 2,4,6-trisubstituted pyrimidine and triazine heterocycles as antileishmanial agents
Sunduru, Naresh,Agarwal, Anu,Katiyar, Sanjay Babu,Nishi,Goyal, Neena,Gupta, Suman,Chauhan, Prem M.S.
, p. 7706 - 7715 (2007/10/03)
A series of 2,4,6 trisubstituted pyrimidines and triazines have been synthesized and screened for its in vitro antileishmanial activity profile in promastigote model. Nine compounds have shown >94% inhibition against promastigotes at a concentration of 10
Facile conversion of pyridine propargylic alcohols to enones: Stereochemistry of protonation of allenol
Erenler, Ramazan,Biellmann, Jean-Fran?ois
, p. 5683 - 5685 (2007/10/03)
The conversion of 4-pyridyl propargylic alcohols 1 to the (E)-propenones 3 and propynones 2 occurs under mild reaction conditions, pyridinium chloride in methanol at room temperature. (Z)-4-Pyridyl propenones 11 are detected as initial products when large
Synthesis of 2,4,6-trisubstituted pyrimidines as antimalarial agents
Agarwal, Anu,Srivastava, Kumkum,Puri,Chauhan, Prem M. S.
, p. 4645 - 4650 (2007/10/03)
A series of 2,4,6-trisubstituted-pyrimidines were synthesized and evaluated for their in vitro antimalarial activity against Plasmodium falciparum. Of the 18 compounds synthesized, 14 compounds have shown MIC in the range of 0.25-2 μg/mL. These compounds
