Diels-Alder Reactions of Cyclopentadiene with Several Ferrocenyl- and η6-Phenyltricarbonylchromium Analogues of Chalcone. Catalytic Effect of SiO2

1996 ◽  
Vol 61 (3) ◽  
pp. 364-370 ◽  
Author(s):  
Monika Prokešová ◽  
Grety Rihs ◽  
Štefan Toma
Keyword(s):  
Good Yield ◽  
Room Temperature ◽  
Catalytic Effect ◽  
Alder Reaction ◽  
Diels Alder ◽  
Nmr Spectrum ◽  
X Ray ◽  
H Nmr ◽  
Diels Alder Reaction ◽  
Electron Withdrawing Group

The Diels-Alder reaction of cyclopentadiene with eight electron deficient dienophiles was studied. The reaction was performed at room temperature using silica gel as an inorganic support, without solvent. Only one of the two possible Diels-Alder adducts was isolated in moderate to good yield. The structure of products with endo-oriented electron-withdrawing group was proved by 1H NMR spectrum and in one case (9b) by X-ray analysis.

scholarly journals Synthesis and Evaluation of Substituted 4,4a-Dihydro-3H,10H-pyrano[4,3-b][1]benzopyran-10-one as Antimicrobial Agent

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Amanpreet Kaur ◽  
Vishal Sharma ◽  
Abhishek Budhiraja ◽  
Harpreet Kaur ◽  
Vivek Gupta ◽  
...  
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Enol Ethers ◽  
Spectral Techniques ◽  
Mass Spectral ◽  
H Nmr ◽  
Diels Alder Reaction ◽  
Electron Withdrawing Group ◽  
Inhibitory Potential ◽  
C Nmr

A series of pyrano[4,3-b][1]benzopyranones (7a–t) were synthesized through hetero-Diels-Alder reaction of substituted 3-formylchromones (5) with enol ethers (6), characterized by IR, 1H NMR, 13C NMR, and mass spectral techniques. All the compounds were evaluated for antimicrobial activity against various bacterial and fungal strains, found to possess significant inhibitory potential, particularly, compounds bearing electron withdrawing group -fluoro such as 7i and 7h. Compounds were also tested and displayed a significant inhibitory potential against methicillin-resistant Staphylococcus aureus (MRSA).

scholarly journals Hetero-Diels–Alder reactions of hetaryl and aryl thioketones with acetylenic dienophiles

2015 ◽  
Vol 11 ◽  
pp. 576-582 ◽  
Author(s):  
Grzegorz Mlostoń ◽  
Paulina Grzelak ◽  
Maciej Mikina ◽  
Anthony Linden ◽  
Heinz Heimgartner
Keyword(s):  
High Pressure ◽  
Room Temperature ◽  
Thermal Conditions ◽  
Alder Reaction ◽  
Diels Alder ◽  
Hydrogen Shift ◽  
Diels Alder Reaction ◽  
Shift Sequence

Selected hetaryl and aryl thioketones react with acetylenecarboxylates under thermal conditions in the presence of LiClO4 or, alternatively, under high-pressure conditions (5 kbar) at room temperature yielding thiopyran derivatives. The hetero-Diels–Alder reaction occurs in a chemo- and regioselective manner. The initially formed [4 + 2] cycloadducts rearrange via a 1,3-hydrogen shift sequence to give the final products. The latter were smoothly oxidized by treatment with mCPBA to the corresponding sulfones.

scholarly journals Enhancing the reactivity of 1,2-diphospholes in cycloaddition reactions

2015 ◽  
Vol 11 ◽  
pp. 169-173 ◽  
Author(s):  
Almaz Zagidullin ◽  
Vasili Miluykov ◽  
Elena Oshchepkova ◽  
Artem Tufatullin ◽  
Olga Kataeva ◽  
...  
Keyword(s):  
Room Temperature ◽  
Cycloaddition Reaction ◽  
Alder Reaction ◽  
Diels Alder ◽  
Alkyl Halides ◽  
Ethyl Iodide ◽  
Para Position ◽  
Cycloaddition Reactions ◽  
Diels Alder Reaction ◽  
Heating Up

Two different approaches have been employed to enhance the reactivity of 1-alkyl-1,2-diphospholes – the introduction of electron-withdrawing groups either at the phosphorus atoms or in the para-position of the arene ring. The alkylation of sodium 1,2-diphospha-3,4,5-triphenylcyclopentadienide with alkyl halides Hal-CH2-R (R = CN, COOEt, OMe, CH2OEt) results in corresponding 1-alkyl-3,4,5-triphenyl-1,2-diphospholes (alkyl = CH2CN (1a), CH2COOEt (1b), CH2OMe (1c), and (CH2)2OEt (1d)), which spontaneously undergo the intermolecular [4 + 2] cycloaddition reactions at room temperature to form the mixture of the cycloadducts, 2a–c, respectively. However the alkylation of sodium 1,2-diphospha-3,4,5-tri(p-fluorophenyl)cyclopentadienide with ethyl iodide leads to stable 1-ethyl-3,4,5-tris(p-fluorophenyl)-1,2-diphosphole (1e), which forms the [4 + 2] cycloadduct 2,3,4,4a,5,6-hexa(p-fluorophenyl)-1-ethyl-1,7,7a-triphospha-4,7-(ethylphosphinidene)indene (2e) only upon heating up to 60 °C. With further heating to 120 °C with N-phenylmaleimide, the cycloadducts 2a–c and 2e undergo the retro-Diels–Alder reaction and form only one product of the [4 + 2] cycloaddition reaction 3a–с, 3e with good yields up to 65%.

scholarly journals On the Catalytic Effect of Water in the Intramolecular Diels–Alder Reaction of Quinone Systems: A Theoretical Study

Molecules ◽  
2012 ◽  
Vol 17 (11) ◽  
pp. 13687-13703 ◽  
Author(s):  
Jorge Soto-Delgado ◽  
Arie Aizman ◽  
Renato Contreras ◽  
Luis Domingo
Keyword(s):  
Catalytic Effect ◽  
Theoretical Study ◽  
Alder Reaction ◽  
Diels Alder ◽  
Effect Of Water ◽  
Diels Alder Reaction

scholarly journals Ionic liquid promoted Diels-Alder Reaction between anthrone and maleimides

2010 ◽  
Vol 8 (2) ◽  
pp. 356-360 ◽  
Author(s):  
Nitin Mirgane ◽  
Sandip Kotwal ◽  
Anil Karnik
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Room Temperature ◽  
Alder Reaction ◽  
Dual Role ◽  
Diels Alder ◽  
Environmentally Benign ◽  
Green Solvents ◽  
Imidazolium Ionic Liquid ◽  
Diels Alder Reaction

AbstractIonic liquids (IL) are gaining importance as green solvents. Imidazolium ionic liquid [bmim]+[Cl]−, an environmentally benign solvent, was found to promote the Diels-Alder reaction between anthrone and maleimides at room temperature with excellent yields. The ionic liquid played a dual role as solvent and catalyst.

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