12 research outputs found
High-temperature microwave effects in liquid media
The heating behavior of high-boiling liquids under microwave (MW) irradiation was investigated. Linear and non-linear heating modes depending on the applied MW power level were observed. The non-linear interactions emerging at “high” power levels are ascribed to electromagnetic oscillations excitations resulting in non-linear heating speed growth and considerable decrease in energy input. The relationship between non-linearity degree and liquids’ viscosity was established. The observed effects have been shown to apply not only to mere heating, but also to high-temperature chemical reactions. Future perspectives and practical applications of the work are also discussed
Heterocyclization Reactions of Pyruvic Acids and Aminoazoles with Controlled Chemoselectivity
The present review includes the analysis of known literature data concerning linear and multicomponent heterocyclizations involving pyruvic acids and aminoazoles. In particular, the review demonstrates the approaches to control regio- and chemoselectivity of these types of treatments and their application to solve the matters of Diversity Oriented Synthesis
A modified Biginelli reaction toward oxygen-bridged tetrahydropyrimidines fused with substituted 1,2,4-triazole ring
A microwave-assisted Biginelli-like three-component condensation using salicylic aldehyde derivatives, acetone, and 5-substituted 3-amino-1,2,4-triazoles instead of the urea component results in the formation of oxygen-bridged tetrahydrotriazolopyrimidine derivatives (11,12-dihydro-5,11-methano[1,2,4]triazolo[1,5-c][1,3,5]benzoxadiazocines) in good yields and high purity. A plausible reaction mechanism for this transformation is discussed in details using literature and experimental data.Artvin Coruh University. BAP-2012.F19.02.24
Council of Higher Education of Turkey, Mevlana Exchange Program: MEV-2016-02
Features of the behavior of 4-amino-5-carboxamido-1,2,3-triazole in multicomponent heterocyclizations with carbonyl compounds
Multicomponent reactions involving polyfunctional 4-amino-5-carboxamido-1,2,3-triazole and cyclic carbonyl-containing CH-acids were studied under conventional thermal heating, microwave and ultrasonic irradiation. The features of the reactions studied were discussed and the optimized procedures for the synthesis of final triazolopyrimidines were elaborated. In contrast to the similar MCRs of numerous other aminoazoles, a change of direction of the heterocyclizations in the case of 4-amino-5-carboxamido-1,2,3-triazole was not observed when microwave or thermal heating was substituted by ultrasonication at ambient temperature
Features of the behavior of 4-amino-5-carboxamido-1,2,3-triazole in multicomponent heterocyclizations with carbonyl compounds
Multicomponent reactions involving polyfunctional 4-amino-5-carboxamido-1,2,3-triazole and cyclic carbonyl-containing CH-acids were studied under conventional thermal heating, microwave and ultrasonic irradiation. The features of the reactions studied were discussed and the optimized procedures for the synthesis of final triazolopyrimidines were elaborated. In contrast to the similar MCRs of numerous other aminoazoles, a change of direction of the heterocyclizations in the case of 4-amino-5-carboxamido-1,2,3-triazole was not observed when microwave or thermal heating was substituted by ultrasonication at ambient temperature
The unexpected influence of aryl substituents in N-aryl-3-oxobutanamides on the behavior of their multicomponent reactions with 5-amino-3-methylisoxazole and salicylaldehyde
The switchable three-component reactions of 5-amino-3-methylisoxazole, salicylaldehyde and N-aryl-3-oxobutanamides under different conditions were studied and discussed. The unexpected influence of the aryl substituent in N-aryl-3-oxobutanamides on the behavior of the reaction was discovered. The key influence of ultrasonication and Lewis acid catalysts led to an established protocol to selectively obtain two or three types of heterocyclic scaffolds depending on the substituent in the N-aryl moiety
The unexpected influence of aryl substituents in N
The switchable three-component reactions of 5-amino-3-methylisoxazole, salicylaldehyde and N-aryl-3-oxobutanamides under different conditions were studied and discussed. The unexpected influence of the aryl substituent in N-aryl-3-oxobutanamides on the behavior of the reaction was discovered. The key influence of ultrasonication and Lewis acid catalysts led to an established protocol to selectively obtain two or three types of heterocyclic scaffolds depending on the substituent in the N-aryl moiety
New tricks of well-known aminoazoles in isocyanide-based multicomponent reactions and antibacterial activity of the compounds synthesized
The well-known aminoazoles, 3-amino-5-methylisoxazole and 5-amino-N-aryl-1H-pyrazole-4-carboxamides, were studied as an amine component in Ugi and Groebke–Blackburn–Bienaymé multicomponent reactions. The first example of an application of aminoazoles in an Ugi four-component reaction was discovered and novel features of a Groebke–Blackburn–Bienaymé cyclocondensation are established and discussed. The heterocycles obtained were evaluated for their antibacterial activity and several of them demonstrated a weak antimicrobial effect, but for most of the compounds a 30–50% increase in biomass of Gram-positive strains (mainly B. subtilis) compared to control was observed