Cycloadditions of C-benzoyl-N-phenylnitrone with furocondensed derivatives

1981 ◽  
Vol 46 (10) ◽  
pp. 2421-2427 ◽  
Author(s):  
Lubor Fišera ◽  
Miloslava Dandárová ◽  
Jaroslav Kováč ◽  
Peter Mesko ◽  
Alžbeta Krutošíková
Keyword(s):  
Transition State ◽  
Furan Ring ◽  
High Yield ◽  
Dipolar Cycloaddition ◽  
Orbital Interactions ◽  
Derivatives Of

Single regioisomeric cycloadduct IIa was formed in a 35% yield upon cycloaddition of the title nitrone Ia with benzofuran. The 1,3-dipolar cycloaddition proceeded with derivatives of 4-R-furo[3,2-b]pyrrole V or VI to the furan ring to form only one regioisomer VIIa or VIIIa in a high yield (93-95%). Dehydrogenation of the latter with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone led to the nitrone X or XII. Also C,N-diphenylnitrone reacted with furopyrroles to afford the cycloadduct VIIIb. Exclusively endo-cycloadducts originated; their transition state was stabilized by secondary orbital interactions.

Glycoconjugation of 4-Methylumbelliferone via “Click Chemistry”

2014 ◽  
Vol 881-883 ◽  
pp. 414-418
Author(s):  
Ru Chun Yang ◽  
Tao Hu ◽  
Ban Peng Cao ◽  
Xi Chen ◽  
Qiang Xiao
Keyword(s):  
Natural Products ◽  
Click Chemistry ◽  
High Yield ◽  
Dipolar Cycloaddition ◽  
Derivatives Of

A series of carbohydrate-conjugated 4-methylumbelliferone were synthesized using 1,3-dipolar cycloaddition “click chemistry” of the azide and alkyne. The reaction is straight forward and in high yield. The strategy will be useful for synthesizing glycoconjugated derivatives of natural products.

Synthesis of Novel 1,2,3-Triazole Derivatives of Isocoumarins and 3,4-Dihydroisocoumarin with Potential Antiplasmodial Activity In Vitro

2020 ◽  
Vol 16 ◽  
Author(s):  
Lucas da Silva Santos ◽  
Matheus Fillipe Langanke de Carvalho ◽  
Ana Claudia de Souza Pinto ◽  
Amanda Luisa da Fonseca ◽  
Julio César Dias Lopes ◽  
...  
Keyword(s):  
Triazole Ring ◽  
Antiplasmodial Activity ◽  
World Health ◽  
Dipolar Cycloaddition ◽  
Terminal Alkynes ◽  
The World ◽  
Ic50 Values ◽  
Derivatives Of ◽  
Active Substances

Background: Malaria greatly affects the world health, having caused more than 228 million cases only in 2018. The emergence of drug resistance is one of the main problems in its treatment, demonstrating the urge for the development of new antimalarial drugs. Objective: Synthesis and in vitro antiplasmodial evaluation of triazole compounds derived from isocoumarins and a 3,4- dihydroisocoumarin. Method: The compounds were synthesized in 4 to 6-step reactions with the formation of the triazole ring via the Copper(I)-catalyzed 1,3-dipolar cycloaddition between isocoumarin or 3,4-dihydroisocoumarin azides and terminal alkynes. This key reaction provided compounds with an unprecedented connection of isocoumarin or 3,4-dihydroisocoumarin and the 1,2,3-triazole ring. The products were tested for their antiplasmodial activity against a Plasmodium falciparum chloroquine resistant and sensitive strains (W2 and 3D7, respectively). Results: Thirty-one substances were efficiently obtained by the proposed routes with an overall yield of 25-53%. The active substances in the antiplasmodial test displayed IC50 values ranging from 0.68-2.89 μM and 0.85-2.07 μM against W2 and 3D7 strains, respectively.

1,3-dipolar cycloaddition in the synthesis of glycoconjugates of natural chlorins and bacteriochlorins

2009 ◽  
Vol 13 (03) ◽  
pp. 336-345 ◽  
Author(s):  
Mikhail A. Grin ◽  
Ivan S. Lonin ◽  
Anna A. Lakhina ◽  
Elena S. Ol'shanskaya ◽  
Alexey I. Makarov ◽  
...  
Keyword(s):  
Triple Bond ◽  
Tautomeric Form ◽  
Click Reaction ◽  
Copper Cation ◽  
Water Soluble ◽  
Dipolar Cycloaddition ◽  
Nmr Studies ◽  
Metal Free ◽  
Cu Complex ◽  
Derivatives Of

Glucose-, galactose- and lactose-containing photosensitizers based on derivatives of chlorophyll a and bacteriochlorophyll a were synthesized with the use of [3+2] cycloaddition between sugar azides and triple bond derivatives of chlorins and bacteriochlorins. Unlike bacteriochlorin cycloimide, chlorin was detected to form a Cu -complex during the click reaction. An approach to the synthesis of metal-free glycosylated chlorins was developed with the use of "protection" by Zn 2+ cation and subsequent demetalation. It is based on the action of alkynyl chlorin e6 derivative Zn -complex, which is resistant to the substitution by copper cation. Bacteriochlorin p cycloimide conjugate with per-acetylated β-D-lactose was obtained and shown to become water-soluble after unblocking of the lactose hydroxy functions. NMR studies allowed for the elucidation of structure, tautomeric form and conformation of the obtained compounds.

Synthesis of enantiomeric β-amino ketones via 1,3-dipolar cycloaddition and chromatographic resolution

1994 ◽  
Vol 72 (5) ◽  
pp. 1347-1350 ◽  
Author(s):  
Chantal Louis ◽  
Sibel Mill ◽  
Vincent Mancuso ◽  
Claude Hootelé
Keyword(s):  
Column Chromatography ◽  
Asymmetric Induction ◽  
High Yield ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Chromatographic Resolution

The cycloaddition reactions of 3,4,5,6-tetrahydropyridine 1-oxide 1 with the homochiral alkynyl sulfoxides 6a–e proceed in high yield to afford, with low asymmetric induction, mixtures of diastereomeric isoxazolines that are readily separated by column chromatography. The resolved isoxazolines can be subsequently converted, by hydrogenolysis, to enantiomeric β-amino ketones.

scholarly journals Allyl type monomers for hard surface coating protection

2019 ◽  
Vol 140 ◽  
pp. 02007
Author(s):  
Larisa Popova ◽  
Anzhelika Tsyrulnikova ◽  
Sergey Vershilov ◽  
Julia Bazarnova ◽  
Ekaterina Aronova ◽  
...  
Keyword(s):  
Tetrabutylammonium Bromide ◽  
Environmental Safety ◽  
Carbon Chain ◽  
High Yield ◽  
Main Reaction ◽  
Fibrous Materials ◽  
Series Of Experiments ◽  
Work Up ◽  
Derivatives Of ◽  
Improve Mass Transfer

Based on the unsaturated derivatives of polyfluoroalkanols chemical products are used to protect solid and fibrous materials surface from the effects of water, oils and other pollutants. A method for obtaining allyl ethers of polyfluoroalkanols (polyfluoroalkoxypropenes) is based on the Williamson ether reaction. This method is a heterophase process. The use of solvents to improve mass transfer requires complementary measures to ensure industrial and environmental safety. It is more preferable to obtain the target ethers in water with PTC. A series of experiments using different chain length polyfluoroalkanols was studied by GLC. Kovats retention indexes of the target ethers were determined. It was found that in the case of lower homologues (CF3CH2OH, (CF3)2CHOH, HCF2CF2CH2OH), the addition of 5-15 vol.% 1,4-dioxane as a solubilizer provides a high yield of products. The application of PTC (tetrabutylammonium bromide) is indispensable for using polyfluoroalkanols with a longer carbon chain (C≥5). PTC invariably provides the almost complete conversion of polyfluoroalkanols. The decomposition process of TBAB becomes noticeable (GLC method) upon completion of the main reaction. Polyfluoroalkoxypropenes form azeotrope with water, which can be used in the work up process.

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