Kinetics and mechanism of reactions of cis- and trans-chalcones with amines

Menger, F. M.; Smith, Jerry H.

doi:10.1021/ja01043a033

Cited by 36 publications

(13 citation statements)

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“…The decrease in the degree of conjugation of the chromophores is related, correspondingly, to both the formation of the PCA products and transformation of the E isomer into the Z isomer. 20, 21 On the basis of specific features of the structures 17 of the starting compounds 1a-c, it can be assumed that the simultaneous influence of the gauche effect 22 from the oxyethylene fragment providing the approach of the terminal groups of the ligands (4.2-8 Å, X ray diffrac tion data) 17 and the kinetic template effect 22 from the К + (Li + , Cs + ) ions can enhance the regio and stereoselec tivity of the intramolecular PCA process due to the short ening of this distance.…”

Section: Methodsmentioning

confidence: 99%

Photochemical transformations of chalcone-podands into cyclobutane-containing benzocrown ethers

et al. 2009

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A method for the synthesis of cyclobutane containing benzocrown ethers by the template photocycloaddition of the corresponding chalcone podands in solutions was developed. It was shown by X ray diffraction analysis, 1 H and 13 C NMR, and UV spectroscopy that the intra molecular [2π+2π] photocycloaddition (PCA) is stereoselective with the predominant forma tion of structures of the β and γ truxinic type. The PCA rate was shown to depend on the size of the oxyethylene spacer and stereoorientation of the chalcone fragments in the podands. The selectivity of the PCA process can be controlled by a change in the concentration of the template (alkaline metal ions) and variation of the wavelength range of irradiation.

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Section: Methodsmentioning

confidence: 99%

Photochemical transformations of chalcone-podands into cyclobutane-containing benzocrown ethers

et al. 2009

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“…It has been proved in many reactions in solution that aggregates can react without previous dissociation. One of the earlier reports is on the butylaminolysis of p-nitrophenyl acetate in chlorobenzene 158 , more recent ones are about the butylaminolysis of 2-hydroxy-5-nitro-˛-toluene sulphonic acid sultone in acetonitrile and toluene 159 , the butylaminolysis of several nitro-substituted 4-nitrophenyl benzoates and cinamates 114 and on the rearrangement of the Z-p-nitrophenylhydrazone of 3-benzoyl-5-phenyl-1,2,4-oxadiazole into 4-benzoylamino-2-p-nitrophenyl-5-phenyl-1,2,3-triazole in benzene 152 . Curiously, in this last reaction, the authors 'have excluded the possibility that the amine behaves as a dimer because in other reactions catalysed by aliphatic secondary amines (e.g.…”

Section: Aggregation Of the Nucleophilementioning

confidence: 99%

S _N Ar Reactions of Amines in Aprotic Solvents

Nudelman¹

2009

Patai's Chemistry of Functional Groups

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“…The biological activities of Mannich bases, such as antimicrobial, [1][2][3]21,22) cytotoxic and anticancer 6,9,23) activities, have been attributed to these liberated a,b-unsaturated ketones which can alkylate nucleophiles, especially thiol groups 1,6,24,25) rather than amino and hydroxyl groups, 26) by Michael type addition reactions of nucleophiles to a,b-unsaturated ketones. 27) In addition, enzyme-catalyzed alkylation of the thiol group of cystein with a,b-unsaturated carbonyl compounds has been observed. 28) The antimicrobial activity of a,b-unsaturated ketones is due to their reactions with essential thiol groups in bacteria and fungi, resulting in b-ketothioethers.…”

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confidence: 99%

Cytotoxicity of Some Azines of Acetophenone Derived Mono-Mannich Bases against Jurkat Cells

Gül

Vepsäläinen

et al. 2003

Biological & Pharmaceutical Bulletin

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Mannich bases have several biological activities such as antimicrobial, [1][2][3][4][5] cytotoxic, [6][7][8][9] anticancer, 10) analgesic, 11) anti-inflammatory, 12,13) diuretic 14,15) and anticonvulsant [16][17][18][19] activities. An amino ketone, Mannich base, containing at least one activated hydrogen atom at the b position to an amino function, can undergo deamination in vivo 20) or under simulated in vitro conditions 1,3,6) to liberate the corressponding a,b-unsaturated ketones. The a,b-unsaturated ketone is an active center for nucleophilic attack. The biological activities of Mannich bases, such as antimicrobial, [1][2][3]21,22) cytotoxic and anticancer 6,9,23) activities, have been attributed to these liberated a,b-unsaturated ketones which can alkylate nucleophiles, especially thiol groups 1,6,24,25) rather than amino and hydroxyl groups, 26) by Michael type addition reactions of nucleophiles to a,b-unsaturated ketones.27) In addition, enzyme-catalyzed alkylation of the thiol group of cystein with a,b-unsaturated carbonyl compounds has been observed. 28)The antimicrobial activity of a,b-unsaturated ketones is due to their reactions with essential thiol groups in bacteria and fungi, resulting in b-ketothioethers.29) Electron densities on b-carbons are lower 30) than on a-carbons in various unsaturated ketones, and thus the attack of the nucleophils should occur at the b-carbon atoms. It was also shown that increased antimicrobial activity was associated with an increased breakdown of the Mannich bases.29) Similarly, a number of a,b-unsaturated ketones have alkylating ability against biologically important nucleophiles to produce cytotoxicity. 21,23) The amino group in Mannich bases would increase the water solubilizing property of the molecule, which may assist in transportation of the compound to the site of action.Production of thiol adducts in the stability studies, 1,3,6) carried out under in vitro physiological conditions (in phosphate buffer with pH 7.4, at 37°C), with 2-mercaptoethanol, various unsaturated ketones or Mannich bases, suggests that a,bunsaturated ketones and Mannich bases producing unsaturated ketones by deamination to exert their antimicrobial activities by thiol alkylation of unsaturated ketones.Clark and co-workers 31) found that the thiol adduct had the greatest fungitoxicity, which was probably due to the same reaction. Dimmock et al. (1994) have shown that Mannich bases of conjugated styryl ketones inhibit one or more of the following enzymes in the glutathione metabolic pathway: namely, glutathione S-transferases, glutathione reductase, gamma-glutamyl transpeptidase and glutathione peroxidase in Candida albicans. 32) They concluded that the antifungal activity of the Mannich bases of conjugated styryl ketones may be due, at least in part, to interference with the GSH metabolic pathway. In one of our previous studies, we observed that mono-Mannich bases and bis Mannich bases decrease the total glutathione level in a dose-dependent manner when Jurkat cells are exposed to the co...

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Kinetics and mechanism of reactions of cis- and trans-chalcones with amines

Cited by 36 publications

References 0 publications

Photochemical transformations of chalcone-podands into cyclobutane-containing benzocrown ethers

Photochemical transformations of chalcone-podands into cyclobutane-containing benzocrown ethers

S _N Ar Reactions of Amines in Aprotic Solvents

Cytotoxicity of Some Azines of Acetophenone Derived Mono-Mannich Bases against Jurkat Cells

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Kinetics and mechanism of reactions of cis- and trans-chalcones with amines

Cited by 36 publications

References 0 publications

Photochemical transformations of chalcone-podands into cyclobutane-containing benzocrown ethers

Photochemical transformations of chalcone-podands into cyclobutane-containing benzocrown ethers

S N Ar Reactions of Amines in Aprotic Solvents

Cytotoxicity of Some Azines of Acetophenone Derived Mono-Mannich Bases against Jurkat Cells

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S _N Ar Reactions of Amines in Aprotic Solvents