An efficient click synthesis of chalcones derivatized with two 1-(2-quinolon-4-yl)-1,2,3-triazoles

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohammed B. Alshammari ◽  
Ashraf A. Aly ◽  
Alan B. Brown ◽  
Md Afroz Bakht ◽  
Ahmed M. Shawky ◽  
...  
Keyword(s):  
Aldol Condensation ◽  
Aldol Reaction ◽  
Click Synthesis

Abstract Chalcones derivatized with 1-(2-quinolonyl)-1,2,3-triazoles were synthesized by reaction of 4-azido-2-quinolones with 1-phenyl-3-(4-propargyloxyphenyl)prop-2-en-1-one, or by aldol reaction of 4-{[1-(2-oxo-1,2-dihydroquinolin-4-yl)-1H-1,2,3-triazol-4-yl]methoxy}benzaldehydes with acetophenone. Whereas, chalcones bearing two 1-(2-quinolonyl)-1,2,3-triazoles were synthesized by reaction of 1,3-bis(4-propargyloxyphenyl)prop-2-en-1-one with 4-azido-2-quinolones, or by aldol condensation between 4-{4-[(4-acetylphenoxy)methyl]-1H-1,2,3-triazol-1-yl}quinolin-2(1H)-ones and 4-{[1-(2-oxo-1,2-dihydroquinolin-4-yl)-1H-1,2,3-triazol-4-yl]methoxy}benzaldehydes.

The Aldol Condensation of Acetaldehyde: the Equilibrium Constant for the Reaction and the Rate Constant for the Hydroxide Catalyzed RetroAldol Reaction

1974 ◽  
Vol 52 (11) ◽  
pp. 2037-2040 ◽  
Author(s):  
J. Peter Guthrie
Keyword(s):  
Equilibrium Constant ◽  
Rate Constant ◽  
Aldol Condensation ◽  
Aldol Reaction ◽  
Enthalpy Change

An indirect thermochemical estimate of the equilibrium constant for the aldol condensation of acetaldehyde suggested that this reaction was much less irreversible than has been believed. The rate of the hydroxide catalyzed retroaldol reaction has been measured; k21 = 2.8 × 10−3 M−1 s−1 at 25°, so that the equilibrium constant is 4.0 × 102 M−1. The γ value for acetaldehyde as addend is 0.40. The enthalpy change for the aldol reaction is −9.84 kcal/mol.

Carbon−Carbon Bond Formation

2008 ◽  
Author(s):  
Jie Jack Li ◽  
Chris Limberakis ◽  
Derek A. Pflum
Keyword(s):  
Natural Products ◽  
Asymmetric Synthesis ◽  
Aldol Condensation ◽  
Bond Formation ◽  
Aldol Reaction ◽  
Aldol Reactions ◽  
Academic Press ◽  
Carbon Carbon Bond ◽  
Stereogenic Centers ◽  
Aldol Addition

Reviews: (a) Vicarion, J. L.; Badia, D.; Carillo, L.; Reyes, E.; Etxebarria, J. Curr. Org. Chem. 2005, 9, 219-235. (b) Mahrwald, R. Ed. In Modern Aldol Reactions; Wiley-VCH: Weinheim, 2004; Vol. 1., pp. 1-335 (c) Mahrwald, R. Ed. In Modern Aldol Reactions; Wiley-VCH: Weinheim, 2004; Vol. 2., pp. 1-345.(d) Machajewski, T. D.; Wong, C.-H. Angew. Chem. Int. Ed. 2000, 39, 1352-1375. (e) Carriera, E. M. In Modern Carbonyl Chemistry; Otera, J.; Wiley-VCH: Weinheim, 2000; Chapter 8: Aldol Reaction: Methodology and Stereochemistry, 227-248. (f) Paterson, I.; Cowden, C. J.; Wallace, D. J. In Modern Carbonyl Chemistry; Otera, J.; Wiley-VCH: Weinheim, 2000; Chapter 9: Stereoselective Aldol Reactions in the Synthesis of Polyketide Natural Products, pp. 249-298. (g) Franklin, A. S.; Paterson, I. Contemp. Org. Synth. 1994, 1 317-338. (h) Heathcock, C. H. In Asymmetric Synthesis; Morrison, J. D., Ed.; Academic Press: Orlando, Fl.; 1984; Vol. 3., Chapter 2: The Aldol Addition Reaction, pp. 111-212. (i) Mukaiyama, T. Org. React. 1982, 28, 203-331. Since the early 1980s, aldol condensations involving boron enolates have gain great importance in asymmetric synthesis, particularly the synthesis of natural products with adjacent stereogenic centers bearing hydroxyl and methyl groups. (Z)-Boron enolates tend to give a high diastereoslectivity preference for the syn-stereochemistry while (E)-boron enolates favor the anti-stereochemistry. Because the B-O and B-C bonds are shorter than other metals with oxygen and carbon, the six membered Zimmerman–Traxler transition state in the aldol condensation tends to be more compact which accentuates steric interactions, thus leading to higher diastereoselectivity. When this feature is coupled with a boron enolate bearing a chiral auxillary, high enantioselectivity is achieved. Boron enolates are generated from a ketone and boron triflate in the presence of an organic base such as triethylamine. Reviews: (a) Abiko, A. Acc. Chem. Res. 2004, 37, 387-395. (b) Cowden, C. J. Org. React. 1997, 51, 1-200.

scholarly journals Enantiodivergent Aldol Condensation in the Presence of Aziridine/Acid/Water Systems

Symmetry ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 930 ◽  
Author(s):  
Adam Marek Pieczonka ◽  
Lena Marciniak ◽  
Michał Rachwalski ◽  
Stanisław Leśniak
Keyword(s):  
Aldol Condensation ◽  
Aldol Reaction ◽  
Aromatic Aldehydes ◽  
Water Systems ◽  
Acid Water ◽  
Asymmetric Aldol ◽  
Asymmetric Aldol Reaction ◽  
Chiral Imines ◽  
Very High

A series of novel chiral imines was synthesized from corresponding aldehydes and 1-(2-aminoalkyl)aziridines with good chemical yields. Such imines were tested as catalysts in the direct asymmetric aldol reaction between aromatic aldehydes and acetone/cyclohexanone in the presence of catalytic amounts of water and an acidic additive. The corresponding aldol products were formed in excellent yields and with very high enantioselectivities (98% and 99% ee, respectively).

Studies towards the Total Synthesis of Kadcotrione B

Synthesis ◽  
2019 ◽  
Vol 52 (05) ◽  
pp. 735-743
Author(s):  
Julakanti Satyanarayana Reddy ◽  
Marri Gangababu ◽  
Patel Manimala ◽  
Aluru Rammohan ◽  
Jillu Singh Yadav
Keyword(s):  
Total Synthesis ◽  
Michael Addition ◽  
Aldol Condensation ◽  
Aldol Reaction ◽  
Side Chain ◽  
Wacker Oxidation ◽  
Efficient Approach ◽  
Salient Features ◽  
Robinson Annulation

A convergent and efficient approach towards the total synthesis of Kadcotrione B is described. For this purpose, the syntheses of two fragments, 6/6/5-fused tricyclic ring and C-9 side chain, were accomplished. The salient features of these syntheses are the utilization of aldol condensation, Evans aldol reaction, Horner–Wadsworth–Emmons olefination, Michael addition, Robinson annulation, and Wacker oxidation.

scholarly journals Chiral Ionic Liquids Based on L-Cysteine Derivatives for Asymmetric Aldol Reaction

Catalysts ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 47
Author(s):  
Karolina Zalewska ◽  
Małgorzata E. Zakrzewska ◽  
Luis C. Branco
Keyword(s):  
Ionic Liquids ◽  
Aldol Condensation ◽  
Aldol Reaction ◽  
Reaction Medium ◽  
Chiral Molecules ◽  
Asymmetric Aldol ◽  
Chiral Ionic Liquids ◽  
Asymmetric Aldol Reaction ◽  
Aldehydes And Ketones ◽  
Asymmetric Catalyst

Structure, and consequently properties, of ionic liquids can be easily tailored by changing cation/anion combinations and/or attaching functional groups. By grafting enantiopure moieties to the framework of ionic liquid it is possible to prepare bioinspired chiral molecules that can serve as a reaction medium, additive or even asymmetric catalyst. In this context, new chiral ionic liquids (CILs), based on biomolecules, such as aminoacids (L-cysteine derivatives), have been synthesised and tested in asymmetric aldol condensation of aldehydes and ketones. The best results were obtained for CILs composed of S-methyl-L-cysteine cation and bis(trifluoromethane)sulfonimide anion, in the reaction of 2- or 4-nitrobenzaldehyde with acetone or cyclohexanone, giving the aldol product in moderate yields 70–76% and high ee values (up to 96%).

BF3·OEt2-Catalyzed Aldol Condensation of Steroid Sapogenins and 2-Oxoacids: A Single Step Conversion of Steroid Spiroketals into Branched α,β-Unsaturated Spirolactones

Synthesis ◽  
2020 ◽  
Vol 52 (15) ◽  
pp. 2241-2244
Author(s):  
Martin A. Iglesias-Arteaga ◽  
Juan E. Hernández-Martínez
Keyword(s):  
Pyruvic Acid ◽  
Aldol Condensation ◽  
Aldol Reaction ◽  
Glyoxylic Acid ◽  
2D Nmr ◽  
Single Step ◽  
Side Chain ◽  
The Novel ◽  
Nmr Techniques ◽  
Plausible Mechanism

BF3·OEt2-catalyzed aldol reaction of steroid sapogenins with glyoxylic acid or pyruvic acid led to compounds in which the novel spirocyclic side chain bears an α,β-unsaturated lactone. The structures of the new spirolactones were established with the aid of combined 1D and 2D NMR techniques. A plausible mechanism is described.

scholarly journals A simple and easy to perform synthetic route to functionalized thienyl bicyclo[3.2.1]octadienes

2020 ◽  
Vol 16 ◽  
pp. 1092-1099
Author(s):  
Dragana Vuk ◽  
Irena Škorić ◽  
Valentina Milašinović ◽  
Krešimir Molčanov ◽  
Željko Marinić
Keyword(s):  
Aldol Condensation ◽  
Thiophene Ring ◽  
Aldol Reaction ◽  
Synthetic Route ◽  
Condensation Reactions ◽  
Thiophene Derivatives ◽  
Wittig Reactions ◽  
Aldol Condensation Reactions ◽  
Derivatives Of

In order to prepare novel polycyclic derivatives of bicyclo[3.2.1]octadiene systems fused with a thiophene ring, photochemical cyclization and aldol condensation reactions were carried out. The starting substrates were easily obtained by a Vilsmeier–Haack reaction of bicyclo[3.2.1]octadiene thiophene derivatives with dimethylformamide. From the obtained carbaldehydes, novel methyl, methoxy, and cyano-substituted styryl thienobenzobicyclo[3.2.1]octadiene derivatives were synthesized through Wittig reactions and subjected to photochemical cyclization, in terms of obtaining the new annulated structures. As part of this study, the aldol reaction of the starting 2-substituted carbaldehyde with acetone was also performed, which produced the thieno-fused benzobicyclo[3.2.1]octadiene compound with an extended conjugation.

scholarly journals Thionylchloride Catalyzed Aldol Condensation: Synthesis, Spectral Correlation and Antibacterial Activities of some 3,5-Dichloro-2-Hydroxyphenyl Chalcones

2013 ◽  
Vol 4 ◽  
pp. 17-38 ◽  
Author(s):  
R. Arulkumaran ◽  
S. Vijayakumar ◽  
R. Sundararajan ◽  
S.P. Sakthinathan ◽  
D. Kamalakkannan ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Thionyl Chloride ◽  
Spectroscopic Data ◽  
Aldol Condensation ◽  
Aldol Reaction ◽  
Antibacterial Activities ◽  
Spectral Correlation ◽  
Effect Of Substituents ◽  
Substituent Constants

A series of substituted styryl 3,5-dichloro-2-hydroxyphenyl ketones [1-(3,5-dichloro-2-hydroxy)-3-phenylprop-2-en-1-one] were synthesized using thionyl chloride assisted Crossed-Aldol reaction. The yields of chalcones were more than 80%. The synthesized chalcones were characterized by analytical and spectroscopic data. From the spectroscopic data the group frequencies were correlated with Hammett substituent constants, F and R parameters. From the results of statistical analysis the effect of substituents were discussed. The antibacterial activities of these chalcones have been evaluated using Bauer-Kirby method.

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