@article {49349, title = {2,3-Difunctionalization of quinones: a gold-catalyzed cascade approach for trifluoromethyl-amination or sulfoximination}, journal = {Chemical Communications}, volume = {60}, year = {2024}, month = {AUG }, pages = {9598-9601}, type = {Article}, abstract = {

A one-pot domino protocol employing gold(i) catalysis has been developed for the cascade trifluoromethyl-amination/sulfoximination of quinones. Togni I serves as the trifluoromethyl installing precursor, while amine or sulfoximine serves as the aminating source. Preliminary investigations suggest a mutual activation of Togni I and the amine precursor, facilitating the facile difunctionalization of quinones with excellent regioselectivity. Extensive substrate scope exploration demonstrates moderate to good yields of difunctionalized products. Application to the natural product Juglone highlights its potential for late-stage modifications in medicinal chemistry and drug discovery. A one-pot domino protocol employing gold(i) catalysis has been developed for the cascade trifluoromethyl-amination/sulfoximination of quinones.

}, issn = {1359-7345}, doi = {10.1039/d4cc01891e}, author = {Sharma, Alpa and Govande, Vijaya and Mahajan, Shivangani and Sawant, Sanghapal D.} } @article {49359, title = {C-H functionalization of imidazo[1,5-a]pyridines: a metal-free approach for methylene insertion to access C(sp2)-C(sp3)-H-C(sp2) bond formation}, journal = {ACS Omega}, volume = {9}, year = {2024}, month = {DEC }, pages = {49071-49080}, type = {Article}, abstract = {

Formaldehyde has been used as a solvent and a source of carbon to insert a methylene group for bridging two imidazo[1,5-a]pyridine molecules without using any metal catalysis. This strategy has been extended on other alkyl-, aryl-, and heteroaryl aldehydes as well. This C(sp2)-C(sp3)-H-C(sp2) bond forming reaction proceeds via C(sp2)H functionalization of imidazo[1,5-a]pyridine and was applied on a wide range of substrates offering moderate to good yields of methylene-bridged/inserted bis-imidazo[1,5-a]pyridines. Most importantly, as an application, the bis-heteroarene product has been demonstrated as a ligand. The ligand-like behavior of bis-imidazo[1,5-a]pyridines has been demonstrated as an extension of current methodology. This reaction works well at the gram scale level.

}, issn = {2470-1343}, doi = {10.1021/acsomega.4c03823}, author = {Mahajan, Shivangani and Sawant, Sanghapal D.} } @article {49086, title = {Diastereoselective synthesis of functionalized spiroindolines via intramolecular ipso-iodocyclization/nucleophile addition cascade reactions of indole-tethered ynones}, journal = {Organic and biomolecular chemistry}, volume = {22}, year = {2024}, month = {MAY }, pages = {3415-3419}, type = {Article}, abstract = {

Herein, we describe a highly diastereoselective approach for synthesizing polyfunctionalized spiroindolines from indolyl-ynones involving an ipso-iodocyclization/nucleophile addition cascade. The developed strategy allows the formation of a spirocyclic core and the installation of two functional groups in a single operation. Also this strategy is accompanied by the generation of two C-C and one C-I bonds and two contiguous stereocenters.

}, issn = {1477-0520}, doi = {10.1039/d4ob00112e}, author = {Bag, Debojyoti and Sawant, Sanghapal D.} } @article {49228, title = {Divergent synthesis of unsymmetrical Bis-heteroaryl ketones via base-promoted cascade reactions of 1,2-alkynedione-derived N-propargylic β-enaminones}, journal = {JOURNAL OF ORGANIC CHEMISTRY}, volume = {89}, year = {2024}, month = {AUG }, pages = {11665-11670}, type = {Journal Article}, keywords = {ASYMMETRIC-SYNTHESIS, heterocycles, intramolecular cyclization, pyrroles}, issn = {0022-3263}, doi = {10.1021/acs.joc.4c01407}, author = {Bag, Debojyoti and Saini, Sheetal and Rathod, Mahesh S. and Sawant, Sanghapal D.} } @article {49048, title = {I2-catalyzed three-component synthesis of 3-selenylated pyrazolo[1,5-a]pyrimidines}, journal = {New Journal of Chemistry}, volume = {48}, year = {2024}, month = {MAY }, pages = {9480-9485}, type = {Article}, abstract = {

A straightforward protocol has been developed to access 3-selenylated pyrazolo[1,5-a]pyrimidines from readily available amino pyrazoles, chalcones, and diaryl/dialkyl diselenides. This I-2-catalyzed methodology is highly useful for synthesizing a wide range of functionalized 3-(aryl/alkylselanyl)pyrazolo[1,5-a]pyrimidine derivatives. Mechanistic investigation disclosed that iodine catalysis is very important in both the cyclization process as well as in the C-H selenylation step. Moreover, the developed reaction conditions are also applicable for the cyclization of amino pyrazole with enaminone followed by C-H selenylation in one pot. The use of simple reagents and catalyst, wide substrate scope, mild and metal-free reaction conditions, and practical applicability are the attractive facets of this approach.

}, issn = {1144-0546}, doi = {10.1039/d3nj05847f}, author = {Choudhuri, Tathagata and Paul, Suvam and Sikdar, Papiya and Das, Sourav and Sawant, Sanghapal D. and Bagdi, Avik Kumar} } @article {49353, title = {Modular synthesis of unsymmetrical indolyl diketones from ynediones via sequential aza-Michael addition/C-H functionalization}, journal = {Organic \& Biomolecular Chemistry}, volume = {22}, year = {2024}, month = {OCT }, pages = {8152-8156}, type = {Article}, abstract = {

Herein, we disclose an efficient approach for the synthesis of unsymmetrical indolyl diketones from easily accessible 1,2-alkynediones involving a sequential aza-Michael addition/C-H Functionalization process. The two-step, one-pot strategy involves the aza-Michael addition of an aniline generating the N-aryl enaminones followed by iodine-mediated C-H functionalization.

}, issn = {1477-0520}, doi = {10.1039/d4ob00946k}, author = {Naveed, Abdul and Bag, Debojyoti and Sawant, Sanghapal D.} } @article {49613, title = {Discovery and biological evaluation of nitrofuranyl-pyrazolopyrimidine hybrid conjugates as potent antimicrobial agents targeting Staphylococcus aureus and methicillin-resistant S. aureus}, journal = {RSC Medicinal Chemistry}, volume = {16}, year = {2025}, month = {MAR}, pages = {1304-1328}, type = {Article}, abstract = {

Nitrofuran and pyrazolopyrimidine-based compounds possess a broad antimicrobial spectrum including Gram-positive and Gram-negative bacteria. In the present work, a series of conjugates of these scaffolds was synthesized and evaluated for antimicrobial activity against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA). Many compounds showed MIC values of \<= 2 mu g ml-1, with compound 35 demonstrating excellent activity (MICs: 0.7 and 0.15 mu g ml-1 against S. aureus and MRSA, respectively) and safety up to 50 mu g ml-1 in HepG2 cells. Compound 35 also exhibited no hemolytic activity, biofilm eradication, and effectiveness against efflux-pump-overexpressing strains (NorA, TetK, MsrA) without resistance development. It showed synergistic effects with vancomycin (S. aureus) and rifampicin (MRSA). Mechanistic studies revealed that compound 35 exhibits good membrane-targeting abilities, as evidenced by DAPI/PI staining and scanning electron microscopy (SEM). In an intracellular model, it reduced bacterial load efficiently in both S. aureus and MRSA strains. With a strong in vitro profile, compound 35 demonstrated favorable oral pharmacokinetics at 30 mg kg-1 and potent in vivo anti-MRSA activity, highlighting its potential against antibiotic-resistant infections.

}, doi = {10.1039/d4md00826j}, author = {Saini, Sapna and Reddy, G. Lakshma and Gangwar, Anjali and Kour, Harpreet and Nadre, Gajanan G. and Pandian, Ramajayan and Pal, Sunny and Nandi, Utpal and Sharma, Rashmi and Sawant, Sanghapal D.} } @article {49546, title = {Interrupted borrowing hydrogen strategy enabled aminomethylation and direct cross-dehydrogenative coupling strategy enabled dicarbonylation reactions of imidazo[1,5-a]pyridines}, journal = {Chemical Communications}, volume = {61}, year = {2025}, month = {FEB}, pages = {3021-3024}, type = {Article}, abstract = {

Herein, we disclose the development of novel aminomethylation and dicarbonylation reactions of imidazo[1,5-a]pyridines. The developed aminomethylation strategy involves a Pd-catalyzed interrupted borrowing hydrogen strategy by utilizing MeOH as the methylene source. A wide variety of imidazo[1,5-a]pyridines and secondary amines were explored for the developed strategy. The established imidazo[1,5-a]pyridine dicarbonylation strategy involves a catalyst/additive-free direct cross-dehydrogenative coupling reaction between imidazo[1,5-a]pyridines and 2-oxoaldehydes.

}, issn = {1359-7345}, doi = {10.1039/d4cc06272h}, author = {Mahajan, Shivangani and Bag, Debojyoti and Kour, Harpreet and Sawant, Sanghapal D.} } @article {49550, title = {Isobavachalcone ameliorates Alzheimer disease pathology by autophagy-mediated clearance of amyloid beta and inhibition of NLRP3 inflammasome in primary astrocytes and 5x-FAD mice}, journal = {Frontiers in Pharmacology}, volume = {16}, year = {2025}, month = {MAR}, pages = {1525364}, type = {Article}, abstract = {

Background and Aim Alzheimer{\textquoteright}s disease (AD) progresses with A beta plaque deposition and neuroinflammation. Given the complexity of AD pathology, single-target therapies have frequently failed in clinical trials. We hypothesized that a multitarget approach could yield better therapeutic outcomes. To this end, we identified isobavachalcone (IBC), a natural compound with dual pharmacological activity in reducing A beta plaques and neuroinflammation.Experimental Procedure Primary astrocytes were isolated from 3 to 4 days old C57BL/6J mice pups for in-vitro assays, while in-vivo studies were conducted on 5x-FAD mice. Protein alterations were evaluated using ELISA, western blotting, immunocytochemistry, and immunohistochemistry. Behavioral analyses included the radial arm maze, open field, and rotarod tests. Data from all in vitro and in vivo experiments were analyzed by using one-way ANOVA and post-hoc Bonferroni tests.Results In-vitro analyses in astrocytes demonstrated that IBC at 5 and 10 mu M concentrations induce AMPK phosphorylation through CAMKK2, promoting autophagy and inhibiting the NLRP3 inflammasome in primary astrocytes. IBC-treated astrocytes exhibited significant clearance of extracellular amyloid beta. Mechanistic studies highlighted autophagy as a key factor in reducing both NLRP3 inflammasome activity and A beta levels. Two months of treatment of 5x-FAD mice with IBC at 25 and 50 mg/kg significantly improved cognitive functions, as evidenced by enhanced memory and motor performance in behavioral tests. Subsequent brain tissue analysis revealed that IBC upregulated autophagic proteins to reduce the brain{\textquoteright}s amyloid beta levels, resulting in decreased expression of neuroinflammation markers.Conclusion IBC effectively ameliorates AD pathology through autophagy-mediated clearance of A beta and suppressing neuroinflammation in 5x-FAD mice.

}, keywords = {Alzheimer disease, Amyloid beta, Autophagy, isobavachalcone, neuroinflammation, NLRP3 inflammasome}, doi = {10.3389/fphar.2025.1525364}, author = {Kour, Dilpreet and Khajuria, Parul and Sharma, Kuhu and Sharma, Alpa and Sharma, Ankita and Ali, Syed Mudassir and Wazir, Priya and Ramajayan, P. and Sawant, Sanghapal D. and Nandi, Utpal and Ahmed, Zabeer and Kumar, Ajay} } @article {49547, title = {Synthesis of isatins via oxone{\textregistered} /TBAI-mediated on-water oxidation of indoles}, journal = {Synthesis-Stuttgart}, volume = {57}, year = {2025}, month = {MAY}, pages = {1583-1591}, type = {Article}, abstract = {

Isatins and their derivatives are important scaffolds in a wide range of pharmaceuticals, bioactive compounds, and functional materials. Herein we describe a new strategy for the synthesis of isatins from indoles via Oxone (R)/TBAI-mediated oxidative dearomatization of indoles in water. The strategy works well with a variety of N-protected indoles and azaindoles.

}, keywords = {dearomatization, indoles, isatins, Oxidation, Water}, issn = {0039-7881}, doi = {10.1055/a-2492-3240}, author = {Khajuria, Pratiksha and Bag, Debojyoti and Sawant, Sanghapal D.} }