Regioselective Pd-Catalyzed Suzuki–Miyaura Borylation Reaction for the Dimerization Product of 6-Bromoimidazo[1,2-a]pyridine-2-carboxylate: Mechanistic Pathway, Cytotoxic and Tubercular Studies

In the pharmaceutical industry, boronic acid and esters play an important role in API-based synthesis. The most efficient way of preparing various active agents is palladium-catalyzed Suzuki–Miyaura borylation reactions. Herein, we report the formation of dimerization product [6,6′-biimidazo[1,2-a]pyridine]-2,2′-dicarboxamide derivatives 7a–j from 6-bromoimidazo[1,2-a]pyridine-2-carboxylate by employing the same conditions. A regioselective borylation of ethyl 6-bromoimidazo[1,2-a]pyridine-2-carboxylate (3) was examined for the formation of ethyl 6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)imidazo[1,2-a]pyridine-2-carboxylate (4a) but it was found to be directed towards the dimerization product 5. The nitrogen-rich system was incorporated into potential anti-cancer and anti-TB agents through acid amine coupling reactions between acid 6 and various amines (dialkyl/cyclic sec./tert.) to form the final adducts 7. Five derived scaffolds were identified as moderately active in TB activity against the H37Rv strain, while two compounds were found to be particularly potent in NCI-60 anti-cancer screening in nine cancer panels.

Design, Synthesis, and Molecular Docking Studies of Some New Quinoxaline Derivatives as EGFR Targeting Agents

The synthesis of some new quinoxaline derivatives (IVa-n) and their structure determination using 1H NMR, 13C NMR and mass spectral analysis was described herein. The in vitro anti-cancer activity of the these compounds (IVa-n) revealed that the compound1-((1-(4-bromophenyl)-1H-1,2,3-triazol-4-yl)methyl)-2-(tetrazolo[1,5-a]quinoxalin-4-yl)pyrazolidine-3,5-dione (IVd) has shown promising activity, whereas, compounds 1-((1-phenyl-1H-1,2,3-triazol-4-yl)methyl)-2-(tetrazolo[1,5-a]quinoxalin-4-yl)pyrazolidine-3,5-dione (IVa), 1-(tetrazolo[1,5-a]quinoxalin-4-yl)-2-((1-(m-tolyl)-1H-1,2,3-triazol-4-yl)methyl)pyrazolidine-3,5-dione (IVb), 1-((1-(3,5-dimethoxyphenyl)-1H-1,2,3-triazol-4-yl)methyl)-2-(tetrazolo[1,5-a]quinoxalin-4-yl)pyrazolidine-3,5-dione (IVh) and 1-((1-(4-nitrophenyl)-1H-1,2,3-triazol-4-yl)methyl)-2-(tetrazolo[1,5-a]quinoxalin-4-yl)pyrazolidine-3,5-dione (IVi) exhibited good to moderate activity against four human cancer cell lines such as HeLa, MCF-7, HEK 293T, and A549 as compared to the doxorubicin. Predominantly, the compound displayed excellent activity over HeLa, MCF-7, HEK 293T, and A549 with IC50 values of 3.20 ± 1.32, 4.19 ± 1.87, 3.59 ± 1.34, and 5.29 ± 1.34 μM, respectively. Moreover, molecular docking studies of derivatives (IVa-n) on EGFR receptor suggested that the most potent compound strongly binds to protein EGFR (pdbid:4HJO) and the energy calculations of in silico studies were also in good agreement with the obtained IC50 values.

Supplementary Information

The online version contains supplementary material available at 10.1134/S1068162022030220.

Miscellaneous Passerini Reaction for α-Acyloxy Carboxamide: Synthesis and Process Optimization Study

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An accelerating effect of “Phase Transfer Catalyst” as additive was exposed for the Passerini three-component reactions and the influence on the reaction rate was studied concerning direct involvement of reactant molecules. The most flexible reaction for the rapid formation of diverse “α-acyloxycarboxamides” using passerini reaction involved multicomponent reactions using miscellaneous 2-(prop-2-ynyloxy)benzaldehyde with various aromatic acid and slightly non-polar fragment i.e. 2-isocyano-2,3,3-trimethylbutane and the representative molecule was characterized with resepct to DEPT135 NMR technique.

Synthesis of Biologically Active Molecules through Multicomponent Reactions

Focusing on the literature progress since 2002, the present review explores the highly significant role that multicomponent reactions (MCRs) have played as a very important tool for expedite synthesis of a vast number of organic molecules, but also, highlights the fact that many of such molecules are biologically active or at least have been submitted to any biological screen. The selected papers covered in this review must meet two mandatory requirements: (1) the reported products should be obtained via a multicomponent reaction; (2) the reported products should be biologically actives or at least tested for any biological property. Given the diversity of synthetic approaches utilized in MCRs, the highly diverse nature of the biological activities evaluated for the synthesized compounds, and considering their huge structural variability, much of the reported data are organized into concise schemes and tables to facilitate comparison, and to underscore the key points of this review.