Synthesis of new functionalized thiazolo pyridine-fused and thiazolo pyridopyrimidine-fused spirooxindoles via one-pot reactions

Synthetic strategies of heterocycle-integrated pyridopyrimidine scaffolds supported by nano-catalysts

Nano-catalysts are of special character for the synthesis of organic molecules with high efficiency, and exceptional physicochemical properties. The objective of this study was to present an overview of the literature reports concerning the synthetic strategies supported by nano-catalysts and the biological features of heterocycle-integrated pyridopyrimidine scaffolds. The basic topics include the strategies that were adopted to prepare pyrido[2,3-d]pyrimidines and pyrido[1,2-a]pyrimidines. The synthesis of pyrido[2,3-d]pyrimidines was attained through two-, three-, or four-component reactions. The synthesis of spirocyclic systems, including spiro[indoline-pyridopyrimidine] derivatives and arylation reactions, was investigated. The anticipated mechanisms of the diverse target products, in addition to the preparation of the nanocatalysts, were scrutinized. The privileged antimicrobial characteristics, challenges, literature overview, and future prospectives were consistently investigated.

Green and Regioselective Approach for the Synthesis of 3-Substituted Indole Based 1,2-Dihydropyridine and Azaxanthone Derivatives as a Potential Lead for SARS-CoV-2 and Delta Plus Mutant Virus: DFT and Docking Studies

Great attempts have been done for the development of novel antiviral compounds against SAR-CoV-2 to end this pandemic situation and save human society. Herewith, we have synthesized 3-substituted indole/2-substituted pyrrole 1,2-dihydropyridine and azaxanthone scaffolds using simple, commercially available starting materials in a one-pot, green, and regioselective manner. Further, the regioselectivity of product formation was confirmed by various studies such as controlled experiments, density functional theory (DFT), Mulliken atomic charge, and electrostatic potential (ESP) surface. In addition, 3-substituted indole 1,2-dihydropyridine was successfully converted into a biologically enriched pharmacophore scaffold, viz., indolylimidazopyridinylbenzofuran scaffold, in excellent yield. Moreover, the synthesized 3-substituted indole 1,2-dihydropyridine/2-substituted pyrroles were analyzed in docking studies for anti-SARS-CoV-2 properties against their main protease (M^pro) and anti-Delta plus properties against their protein of the Delta plus K417N mutant. Further, the drug-likeness prediction was analyzed by the Lipinski rule and other pharmacokinetic properties like absorption, distribution, metabolism, excretion, and toxicity using preADMET prediction. Interestingly, the docking results show that out of 20 synthesized compounds, 5 of them for M^pro of SAR-CoV-2 and 9 of them for 7NX7 spike glycoprotein's A chain of Delta plus K417N show greater binding affinity when compared with remdesivir that is the first to receive FDA approval and is currently used as a potent drug for the treatment of COVID-19. These results suggest that indole/pyrrole substituted 1,2-dihydropyridine derivatives are capable of combating SARS-CoV-2 and its Delta plus mutant.

Expeditious entry into carbocyclic and heterocyclic spirooxindoles

Spirocyclic frameworks have attracted synthetic practitioners due to their unique three-dimensional assembly, improved metabolic stability, solubility, and increased molecular complexity with regard to planar architectures. A recent surge in the number of spirocyclic oxindoles inhibiting enzymes, moderating unique protein-protein interactions, modulating receptors and transporters is testament to their prevalence. Against this background, the construction of spirocyclic frameworks containing an oxindole moiety as a torsional switch via stereoselective methods is in great demand. Herein we present a summary of the past three years in the progress of metal, organic molecule, nanostructured particle mediated, and even uncatalyzed versions of the highly diastereo- and enantioselective pathways leading to oxindole spirocycles.

Recent Advances in the Application of Barbituric Acid Derivatives in Multicomponent Reactions

Abstract:

Barbituric acid is a pyrimidine heterocyclic organic compound, which is pharmacologically active. It is important to build structures containing various medicinal activities. This compound attracts the scientific research community in organic synthesis. It can be used in the synthesis of polyheterocyclic, natural, medicinal compounds, and organic sensors. Herein, the utilization of barbituric or thiobarbituric acid in multicomponent reactions is reported from 2016-2021 in this manuscript.

Recent Progress in the Synthesis of Heterocycles Based on 1,3-Diketones

N,O-heterocycles containing the dicarbonyl ring play a significant role in heterocyclic and therapeutic chemistry. Since the discovery of 1,3-diketones, numerous research works have been achieved regarding the synthesis and its chemical reactivity. In this review, we have described the most relevant publications involving β-diketone compounds published during the period between 2018 to date. In addition, we include the 1,3-diketones-based heterocyclic compounds prepared by various synthetic methodologies.