Journal of Heterocyclic Chemistry最新文献

For the first time, the interaction of perfluoro-1,4-naphthoquinone with various 5-aminopyrazoles was investigated. It was shown that three types of products can be obtained depending on the structure of starting aminopyrazole. For all examples, the substitution of one fluorine atom in quinone moiety was observed. Wherein, in most cases, the starting aminopyrazoles act as a C-nucleophile leading to 2-(5-aminopyrazol-4-yl)-3,5,6,7,8-pentafluoronaphthalene-1,4-diones. At the same time substrates unsubstituted at ring nitrogen atom regiospecifically react at aminogroup resulting in the formation of 2,5,6,7,8-pentafluoro-3-((pyrazol-5-yl)amino)naphthalene-1,4-diones. Besides that, the absence of steric hindrance in the pyrazole unit allowed us to direct the process at nitrogen atom in Position 2 and synthesize zwitter-ionic 3-(5-aminopyrazol-2-ium-2-yl)-5,6,7,8-tetrafluoro-1,4-dioxo-1,4-dihydronaphthalen-2-olates. The structures of two types of obtained products were confirmed by x-ray analysis.

A GaCl₃-catalyzed [3 + 2]-cycloaddition/intramolecular esterification cascade of donor–acceptor cyclopropane-1,1-diesters with salicylaldehydes has been reported. A wide range of tetrahydro-4H-furo[3,2-c]chromen-4-ones have been efficiently delivered in moderate to good yields. Mechanistic studies suggest that the reaction involves the [3 + 2]-cycloaddition followed by intramolecular esterification to access 4H-furo[3,2-c]chromenones.

An efficient access to novel families of 7-membered dibenzodiazepines and 6-membered benzo[c]cinnoline derivatives has been elaborated. The synthetic strategy is based on a copper-catalyzed double N-arylation of cyclic diaryliodoniums with imidamides and 4-substituted 1, 2, 4-triazoline-3, 5-diones (TADs) respectively under ambient reaction conditions. A mechanistic rationale for the double N-arylation is discussed.

The synthesis of functionalized (trichloromethyl)quinazoline-4(1H)-one with high yields through a novel three-component intramolecular CH activation reaction from trichloroacetonitrile, benzoyl chlorides, and various primary amines is a remarkable achievement in organic chemistry. This strategy offers a direct and efficient route to access complex molecular structures from readily available starting materials. The use of copper (I) as a catalyst and L-proline as a ligand in tetrahydrofuran at room temperature highlights the importance of transition metal catalysis in enabling selective CH activation processes. Furthermore, the subsequent transformation of the obtained product with phenylacetylene and sodium azide in the presence of a copper catalyst in water solvent at room temperature demonstrates the versatility of this synthetic approach in accessing new (1,2,3-triazole)-quinazoline-4(1H)-one derivative. The combination of available starting materials, catalytic systems, mild reaction conditions, and ease of purification procedures contributes to the attractiveness of this method for the synthesis of diverse (trichloromethyl)quinazoline-4(1H)-one and (1,2,3-triazole)-quinazoline-4(1H)-one derivative.

Herein, we have developed palladium-trifluoroacetate-catalyzed carbo-palladation reaction of pyrrole-2-carbonitriles and aryl boronic acids leading to functionally diverse pyrrolo[1,2-α]pyrazines under thoroughly optimized reaction conditions. The reaction proceeded smoothly and allowed the diversity-oriented synthesis of pyrrolo[1,2-α]pyrazines with broad substrate scope with respect to pyrrole-2-carbonitriles and aryl boronic acids.

A formal [3 + 3] cycloaddition of 4-hydroxycoumarins with propargylicalcohols was established under mild conditions. This strategy utilizes diazonium tetrafluoroborate as the Lewis acid catalyst and provides a practical approach for delivering pyranocoumarin derivatives in moderate to high yield. The structure of the cycloadduct was unequivocally confirmed by single-crystal x-ray diffraction. The potential synthetic applications of this strategy were also highlighted by the scale-up experiment and further synthetic transformation.

Synthesis of 18 tryptanthrin-triazole hybrid molecules by employing Cu(I)-catalyzed azide-alkyne [3 + 2] cycloaddition (CuAAC) between tryptanthrin oxime O-propargyl ether and aromatic azides is described here. The exclusive formation of E-triazoles was confirmed by theoretical studies using the M06-2x/6–311++G(d,p) level. From the synthesized triazoles, four of them have been selected and were subjected to in vitro anticancer activity studies against selected cell lines. Furthermore, in silico studies have been conducted for the most active compound, 5h, and it suggested that various noncovalent interactions and one conventional hydrogen bond enhance the stability of the complex (binding affinity = −11.29 kcal/mol). ADMET (Absorption, Distribution, Metabolism, Excretion and Toxicity) studies also prove the increased biological potency of 5h.

Quinazolines and their derivatives occur in various natural products and pharmaceuticals, and thus, various methods of synthesizing quinazolines have been explored. They have traditionally been synthesized via two-component reactions, but these strategies often suffer from the unavailability of the starting materials and limited substrate scopes. To overcome these problems, three-component reactions using additional N sources were developed. Aldehydes were initially used in these reactions, but alcohols are greener and less toxic than aldehydes. However, the previously reported methods involving the use of alcohols require the utilization of transition metal catalysts, ultrahigh temperatures, and extended durations. Thus, an efficient, practical method of synthesizing quinazolines using alcohol is desirable. A facile one-pot three-component method of synthesizing quinazolines utilizing alcohols, 2-aminobenzoketones, and ammonium acetate is reported for the first time, using active MnO₂ and tert-butyl hydrogen peroxide (TBHP) as synergistic oxidants. MnO₂ and TBHP play dual roles: First, they oxidize the alcohol to the aldehyde and then facilitate the transformation of the intermediate into the product. During alcohol oxidation, the synergistic effect of MnO₂ and TBHP is particularly evident. The aldehydes generated in situ via alcohol oxidation undergo immediate subsequent reactions, thereby minimizing their volatilization and side reactions, such as oxidation and polymerization.

This study describes a simple, inexpensive, and effective method for the synthesis of new 5-imino-7-aryle-5H-thiazolo[3,2-a]pyrimidine-3-carbonitrile derivatives 4a-e using a green procedure that does not require the use of heat or a base, creating a strategy that meets both economic and environmental demands. Various synthesized products were characterized via diverse techniques such as ¹H-NMR, infrared (FT-IR), Mass spectroscopy (MS), and single crystal X-ray diffraction. Using a fluorescence spectrometer, the 5-imino-7-phenyle-5H-thiazolo[3.2-a]pyrimidine-3-carbonitrile 4a has been tested as a potent fluorescent agent in mixture of DMSO/Water at 10⁻⁴ M in one hand, and on the other hand the results of our fluorescence evaluation studies with metal ions (Pb(II), Ba(II), Cd(II), Ni(II), Mn(II), Hg(II), Zn(II), Fe(II), Co(II), Cu(II), La(II), Cr(III), and Fe(III)) have shown that this compound exhibits a turn-on and turn-off of the fluorescence to 4a compound with these metals, what forms poor to good interaction by these ions. This result represents the emergence of a new potential ligand for the two heavy cations Cd(II) and Pb(II), which are toxic and polluting, and whose detection is currently of high interest. As well, In the molecular docking evaluation study, it was determined that the 4e molecule has an exceptional ability to inhibit the binding energy of the tubulin protein by −9.13 kcal/mmol, compared to other compounds. The results demonstrate the possibilities for a novel oral medication application.

Imidazole moiety when fused with other heterocyclic system form numerous compounds with different types of pharmacological and biological activities. In this review, we discussed a comprehensive analysis of the synthetic methodologies and reaction mechanisms for imidazo-fused heterocyclic molecules. These molecules represent a crucial class of compounds due to their significant applications and versatile chemical reactivity. This article meticulously examined various synthetic routes for the construction of imidazo-fused heterocycles, ranging from traditional methods to modern approaches such as microwave-assisted reactions, NPs-catalyzed reactions, light-mediated synthesis, electrochemical reactions, and transition metal-free synthesis routes. By consolidating the current knowledge and highlighting future directions, this review aims to serve as a treasure for research community in the fields of organic chemistry, medicinal chemistry, and material science.