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In the pursuit of advanced functional materials, π‐extended porphyrin derivatives, particularly β,β‐benzannulated tetrapyrroles, have garnered significant attention due to their unique structural and electronic properties. This study refines existing methodologies for the selective synthesis of opp‐A2B2‐symmetric benzoporphyrins based on 4,7‐dihydro‐4,7‐ethano‐2H‐isoindole or [3,4]epipyrroloanthracene building blocks. By condensation of preformed biscarbinols, this approach overcomes regioselectivity challenges in traditional condensation methods, which typically favor other isomers over the desired opp‐A2B2 regio derivative. The analysis of the resulting C2v‐symmetric tetrapyrroles exhibit distinct optoelectronic, electrochemical, and structural properties compared to their fully symmetrical A4 counterparts, underscoring their potential in organic optoelectronics applications.

In this study, a novel series of 1,2,4-triazolo[4,3- a ]quinoxalines containing a sulfonamide moiety was designed and synthesized through regioselective synthesis from 2 and/ 3-hydrazino-6-(pyrrolidin-1-ylsulfonyl)quinoxaline derivatives 5 and 7 . The structures of two isomers were confirmed and characterized by IR, 1 H NMR, 13 C NMR, and elemental analysis data. The synthesized 1,2,4-triazolo[4,3- a ]quinoxaline derivatives 8–13 were evaluated for their antidiabetic activities by targeting α-amylase and α-glucosidase, as well as for their anti-Alzheimer activity by targeting acetylcholinesterase (AChE) at a concentration of 100 µM. Structure-activity relationship (SAR) analysis was conducted for all analogs, emphasizing the nature of the substituent groups at position one of the triazole nucleus and the positioning of the sulfonamide moiety. For α-amylase and α-glucosidase activity, the designed compounds exhibited moderate to good activity, with inhibitory percentage values ranging from 21.85 ± 0.01% to 64.70 ± 0.02% and from 23.93 ± 0.01% to 75.36 ± 0.01%, respectively. The N -allyl-[1,2,4]triazolo[4,3- a ]quinoxalin-1-amine derivative 10a demonstrated the most significant inhibitory activity, with percentages of 64.70 ± 0.02% and 75.36 ± 0.01% against α-amylase and α-glucosidase, respectively, in comparison to acarbose (IP = 67.33 ± 0.01% and 57.79 ± 0.01%). Furthermore, the 1,2,4-triazolo[4,3- a ]quinoxaline derivatives 8–13 exhibited low to moderate inhibitory percentages against the acetylcholinesterase enzyme, except for the 1-methyl-[1,2,4]triazolo[4,3- a ]quinoxaline derivative 11b which demonstrated the highest inhibitory percentage of 44.78 ± 0.01%, compared to donepezil (IP = 67.27 ± 0.60%). Moreover, the promising derivative 10a demonstrated exceptional inhibitory activity, exhibiting IC 50 values of 3.46 ± 0.06 µM and 6.89 ± 0.09 µM against α-glucosidase and α-amylase, respectively, when compared to acarbose, which has IC 50 values of 4.27 ± 0.06 µM and 5.90 ± 0.09 µM. Finally, molecular docking simulations were performed for compound 10a within α-amylase (PDB: 2QV4) and α-glucosidase (PDB: 3W37), while compound 11b was analyzed within acetylcholinesterase (AChE) (PDB: 4EY7) to assess binding affinity and to explore the binding interactions with the active sites of the enzymes.

Polyanionic cellulose carbamates were synthesized by rapid and efficient homogeneous aminolysis of cellulose carbonate half-esters in an ionic liquid/DMF medium. Cellulose bis-2,3-O-(3,5-dimethylphenyl carbamate), as a model compound, reacted with different chloroformates to cellulose carbonates. These intermediates were subjected to aminolysis, for which both the reactivity of different chloroformates towards C6-OH and the reactivity/suitability of the respective carbonate half-ester in the aminolysis were comprehensively studied. Phenyl chloroformate and 4-chlorophenyl chloroformate readily reacted with C6-OH of the model cellulose derivative, while 4-nitrophenyl chloroformate did not. The intermediate 4-chlorophenyl carbonate derivative with the highest DS (1.05) was then used to evaluate different aminolysis pathways, applying three different amines (propargyl amine, β-alanine, and taurine) as reactants. The latter two zwitterionic compounds are only sparingly soluble in pure DMF as the typical reaction medium for aminolysis; therefore, several alternative procedures were suggested, carefully evaluated, and critically compared. Solubility problems with β-alanine and taurine were overcome by the binary solvent system DMF/[EMIM]OAc (1:1, v/v), which was shown to be a promising medium for rapid and efficient homogeneous aminolysis and for the preparation of the corresponding cellulose carbamate derivatives or other compounds that are not accessible by conventional isocyanate chemistry. The zwitterionic cellulose carbamate derivatives presented in this work could be promising chiral cation exchangers for HPLC enantiomer separations.

Building on the significant potential of pyrimidine-based molecules for optoelectronic applications, we designed and synthesized a new series of spiro[indoline-pyrido-pyrimidine] derivatives with excellent selectivity. These compounds exhibit novel photochromic and thermochromic properties, addressing the growing need for diagnostic agents with minimal side effects. The regioisomers were identified using 1D, 2D homonuclear and heteronuclear correlation NMR spectroscopy, along with X-ray crystallography. Dynamic 1 H NMR (DNMR) studies revealed that the major isomer ( 4 sa ) is more stable than the minor isomer ( 4 sb ). Optical, electrochemical, and structural analyses of compounds 4aa , 4ab , 4 sa , and 4sb demonstrated the feasibility of chemical reactions converting closed-ring structures to open-ring structures, resulting in notable optical properties due to ring opening. To validate the experimental data, density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were conducted at the B3LYP/6-31G(d) level, offering insights into the electronic structure and absorption spectra. Additionally, Gibbs free energy (ΔG) calculations were performed to elucidate the proposed mechanism for open-ring compounds named 5 and 7. This work emphasizes employing the citric acid as a bio-organic catalyst in a green, multi-component domino reaction, underscoring its environmentally sustainable approach. These studies reveal the potential of these compounds for advanced optical and temperature sensing applications, aligning theoretical and experimental approaches to establish a robust foundation for future research.

COVID-19 has proved to be a global health crisis during the pandemic, and the emerging JN.1 variant is a potential threat. Therefore, finding alternative antivirals is of utmost priority. In the current report, we present the synthesis of new and potential anti-viral pyrazoline compounds. Here we report a chemical scheme where β-aryl β-anilino ketones react with phenyl hydrazine in potassium hydroxide to give the corresponding 3,5-diarylpyrazoline. The protocol is applicable to a variety of β-amino ketones and tolerates several functional groups. This method is efficient and proceeds regioselectivity since the β-Anilino group acts as a protecting group for alkenes of chalcones. We identified the NSP3-microdomain (Mac-1) of SARS-CoV-2 as a putative target for newly synthesized triaryl-2-pyrazoline compounds. The molecular dynamics simulation-based free energy estimation suggests compounds 7a, 7d, 7 g, 7i, 7k, and 7 L as promising Mac-1 inhibitors. The detailed structural inspection of MD simulation trajectories sheds light on the structural and functional dynamics involved in the SARS-CoV-2 Mac-1. The data presented here is expected to guide the design and development of better anti-SARS-CoV-2 therapies.

Pyrazole core represents a privilege scaffold in medicinal chemistry; a number of pyrazole compounds are endowed with various pharmacological activities in different therapeutic areas including antimalarial treatment. Supported by this evidence, a series of 5-anilino-3-(hetero)arylpyrazoles were evaluated for their antiplasmodial activity in in vitro assays. The compounds were synthesized according to regioselective and versatile protocols that combine active methylene reagents, aryl isothiocyanates and (substituted)hydrazines. The considered derivatives 2 allowed the definition of consistent structure–activity relationships and compounds 2b,e,k,l were identified as the most interesting derivatives of the series showing micromolar IC50 values against chloroquine-sensitive and chloroquine-resistant Plasmodium strains. Additionally, the most active anilino-pyrazoles did not show any cytotoxicity against tumor and normal cells and were predicted to have favorable drug-like and pharmacokinetic properties.

New 2-thioxopyrimidin-4-ones capable of participating in regioselective reactions with functionally diverse hydrazonoyl chlorides towards angular regioisomers, rather than linear ones, were designed and synthesized to form stereoisomeric cis- and trans-hexahydro [1,2,4]triazolo[4,3-a]quinazolin-9-ones to be tested as antitumor candidates. The angular regiochemistry of the products was verified through crystallographic experiments and NMR studies. In addition, the regioselectivity of the reaction was found to be independent of the stereochemistry of the used 2-thioxopyrimidin-4-one. Only compound 4c demonstrated satisfactory growth inhibition against all the cancer cells used among all the produced drugs.

Linaclotide is a 14-amino acid residue peptide approved by the FDA for the treatment of irritable bowel syndrome with constipation (IBS-C), which activates guanylate cyclase C to accelerate intestinal transit. Here we show a new method for the synthesis of linaclotide through the completely selective formation of three disulfide bonds in satisfactory overall yields via mild oxidation reactions of the solid phase and liquid phase, using 4-methoxytrityl (Mmt), diphenylmethyl (Dpm) and 2-nitrobenzyl (O-NBn) protecting groups of cysteine as substrate, respectively.

A carbocatalytic, regioselective synthesis of C 3 -N alkylated coumarins has been reported under solvent-free conditions. This synthetic protocol provides a series of C 3 -N alkylated coumarins in good yields starting directly from coumarins and azides in the presence of GO nanosheets without any additives or ligands needed. In contrast to the frequently applied synthetic strategy that involves nucleophilic substitution of benzylamine/benzyl alcohol with halogenated coumarins in the presence of Pd or Cu catalyst for the generation of N-alkylated coumarins, here, coumarins directly reacts with azides via azide-alkene 1,3-dipolar cycloaddition/ring cleavage/1,2-H migration/denitrogenation, followed by 1,3-H migration to afford C 3 -N alkylated coumarins.

2,5-Di(trimethylsilanyl)dithieno[2,3- b :3′,2′- d ]thiophene ((TMS) 2 - bb - DTT ), 2,5-di(trimethylsilanyl)diseleno[2,3- b :3′,2′- d ]thiophene ((TMS) 2 - bb - DST ), and 2,5-di(trimethylsilanyl)diseleno[2,3- b :3′,2′- d ] selenophene ((TMS) 2 - bb - DSS ) were used as starting materials to synthesize three S-shaped double helicenes (i.e., DH - 1 , DH - 2 , and DH - 3 ) through monobromination, formylation, the Wittig reaction, and double oxidative photocyclization. The photocyclization was a highly regioselective process. The molecular structures of DH - 1 and DH - 2 were confirmed by X-ray single-crystal analysis. Multiple intermolecular interactions, such as C–S, C–Se, S–S, S–Se, and Se–Se, were observed in the crystal packing structures of these compounds. Spectroscopic results and our previous work showed that the combination of molecular structure change and heteroatom replacement from S to Se could precisely modulate molecular energy levels.