5-Acetyl-3-cyano-6-methyl-4-styryl/(4-methxphenyl)pyridine-2(1H)-thiones (IIa), (IIb) were synthesized via reacting ylidenecyanothioacetamides (Ia), (Ib) with acetylacetone. Treatment of compound (IIa) with certain N-aryl-2-chloroacetamides, under mild basic conditions (sodium acetate trihydrate), gave the expected 2-((5-acetyl-3-cyano-6-methyl-4-styrylpyridin-2-yl)thio)- N-arylacetamides (IIIa–IIIf). Conversion of (IIIa–IIIf) into the corresponding thienopyridines (IVa–IVf) was carrired out in boiling ethanol containing anhydrous sodium carbonate. Reaction of (IVb),(IVf) with 2,5-dimethoxytetrahydrofuran afforded pyrrolylthienopyridines (Vb), (Vf). Cyclocondensation of (IVb), (IVf) with triethyl orthoformate produced pyridiothienopyrimidinones (VIb), (VIf). Diazotization of compounds (IVb–IVd) afforded triazinones (VIIb–VIId). Compound (IIa) was treated with 2-chloromethyl-1H-benzimidazole to afford 2-(((1H-benz[d]imidazol-2-yl)methyl)thio)-5-acetyl-4-(4-methoxy- yphenyl)-6-methylnicotinonitrile (VIII). Cyclization of (VIII) into 1-(3-amino-2-(1H-benz[d]imidazol- 2-yl)thienopyridine (IX) was carried out. Compound (IX) underwent different reactions with some reagents to furnish condensed benzimidazoles (X–XIII). [1,2,3]Triazine (XIV) was synthesized via diazotization of (IX). Some of our target derivatives had been examined in vitro for their antibacterial activities against MRSA and E. coli, and promising results obtained. Most of new styrylpyridines were evaluated for their insecticidal activity towards A. gossypii (Glover, 1887) and considerable results recorded.

2-((3-cyano-4,6-distyrylpyridin-2-yl)thio)acetophenone (2) was synthesized by the reaction of 3-cyano-4,6-
distyrylpyridin-2(1H)-thione (1) with an alkylating agent, phenacyl bromide in the presence of fused sodium
acetate and ethanol. Compound 2 underwent Thorpe-Ziegler cyclization upon heating in ethanolic sodium
ethoxide solution to yield the target, 3-amino-2-benzoyl-4,6-distyrylthieno[2,3-b]pyridine (3). Elemental and
spectral characterizations of the newly synthesized compounds 2 and 3 have been achieved. Both compounds 2 and 3 exhibited significant insecticidal activities after treated for 24 and 48 h compared with the reference compound, acetamiprid, when screened for their insecticidal activity against the nymphs and adults of cowpea aphid, Aphis craccivora Koch. Therefore, the results obtained are very promising,and accentuate on the importance of such heterocyclic pyridine compounds as efficient pesticides.

Ethyl 5-cyano-1,6-dihydro-2-methyl-4-(2′-thienyl)-6-thioxonicotinate (A) was synthesized and reacted with ethyl chloroacetate in the presence of sodium acetate or sodium carbonate to give ethyl 5-cyano-6-((2-ethoxy-2-oxoethyl)thio)-2-methyl-4-(2′-thienyl)nicotinate (1a) or its isomeric thieno[2,3-b]pyridine 2a. 3-Aminothieno[2,3-b]pyridine-2-carboxamide 2b was also synthesized by the reaction of A with 2-chloroacetamide. The reaction of 1a with hydrazine hydrate in boiling ethanol gave acethydrazide 3. Heating ester 1a with hydrazine hydrate under neat conditions afforded 3-amino-1H-pyrazolo[3,4-b]pyridine 10. Compounds 2b, 3, and 10 were used as precursors for synthesizing other new thieno[2,3-b]pyridines and pyrazolo[3,4-b]pyridines containing mainly the ethyl nicotinate scaffold. Structures of all new compounds were confirmed by elemental and spectral analyses. Most of the obtained compounds were evaluated for their insecticidal activity toward the nymphs and adults of Aphis gossypii (Glover,1887). Some compounds such as 4, 9b, and 9c showed promising results. The effect of some sublethal concentrations, less than LC₅₀, of compounds 4, 9b, and 9c on the examined Aphis was subjected to a further study. The results demonstrated that exposure of A. gossypii nymphs to sublethal concentrations of compounds 4, 9b, and 9c had noticeable effects on their biological parameters, i.e., nymphal instar duration, generation time, and adult longevity. The highest concentration C1 of all three compounds increased the nymphal instar duration and generation time and decreased adult longevity and vice versa.

This work reports the preparation of a new dihydroisoquinoline derivative whose structure was characterized by IR, NMR (¹H, ¹³C), MS and verified through single-crystal X-ray analysis. The mean planes of the acetyl and 4-chlorophenyl groups in the title molecule are nearly perpendicular to that of the pyridine ring. In the crystal, π-stacking and C—H···O hydrogen bond interactions involving the pyridine ring and the nitrile group of an adjacent molecule form the full 3-D structure. Hirshfeld surface (HS) analysis shows the topology of the molecules in the crystal packing. Fingerprint (FP) diagrams show the percentage contribution of several intermolecular interactions where H‧‧‧H interactions have a significant contribution (46%). The DFT study reveals a low HOMO-LUMO gap and significant charge transfer is indicated by the natural bonding orbitals (NBO) and frontier molecular orbital (FMO) analyses. Non-covalent interactions and bond characteristics were investigated using the quantum theory of atom in the molecule (QTAIM) and ELF analysis. FMO analysis was used to calculate the HOMO-LUMO energy gap and orbital energies. Using the DFT method, parameters such as global reactivity were calculated. Using the implicit solvent model, properties such as optical and nonlinear optical (NLO) were characterized in the solvent (water) phase and gas phase. The affinity of the title molecule for Monoamine Oxidase B was examined using molecular docking and molecular dynamics studies and these results showed good binding of the target molecule.

Researchers worldwide are developing innovative luminescent systems with exceptional features like high sensitivity. Luminescent frameworks based on aggregation-induced emission (AIE) have emerged as promising candidates for various applications. Over the past decade, porous materials like metal-organic cages (MOCs) incorporating AIE luminogens (AIEgens) have demonstrated exceptional performance. Chirality plays a significant role in specific non-racemic luminescent systems, particularly circularly polarized luminescence (CPL). Chiral organic materials coordinated with metals, including MOCs, have gained importance as they combine organic ligands and coordination-bonded metal centers, enabling the design of novel structures with CPL. These materials have shown exciting potential applications in fields like CPL-OLED, chiral recognition, and sensing. This review article provides an overview of the recent progress in emissive porous materials, specifically MOCs, and their possible applications. Additionally, the review focuses on the recent progress in AIE_gen-based cages, CPL-active cages, and non-AIE_gen-based cages, their practical applications in sensing and enantioselectivity, and future prospects. Key challenges in AIE-based POCs and MOCs include limited stability, affecting their use in wide-surface thin films, and the need to understand molecular structure and topology impacts. Future efforts should enhance luminescence efficiency and explore applications in chiral sensing, supramolecular assemblies, bioimaging, and optoelectronics, driving innovation in smart materials.

In this study, we synthesized new 5,6,7,8-tetrahydroisoquinolines and 6,7,8,9-tetrahydrothieno[2,3-c]isoquinolines based on 4-(N,N-dimethylamino)phenyl moiety as expected anticancer and/or antioxidant agents. The structure of all synthesized compounds were confirmed by spectral date (FT-IR, ¹H NMR, ¹³C NMR) and elemental analysis. We evaluated the anticancer activity of these compounds toward two cell lines: A459 cell line (lung cancer cells) and MCF7 cell line (breast cancer cells). All tested compounds showed moderate to strong anti-cancer activity towards the two cell lines. Compound 7e exhibited the most potent cytotoxic activity against A549 cell line (IC₅₀: 0.155 µM) while compound 8d showed the most potent one against MCF7 cell line (IC₅₀: 0.170 µM) in comparison with doxorubicin. In addition, we examined the effect of compounds 7e and 8d regarding the growth of A549 and MCF7 cell lines, employing flow cytometry and Annexin V-FITC apoptotic assay. Our results showed that compound 7e caused cell cycle arrest at the G2/M phase with a 79-fold increase in apoptosis of A459 cell line. Moreover, compound 8d caused cell cycle arrest at the S phase with a 69-fold increase in apoptosis of MCF7 cell line. Furthermore, we studied the activity of these compounds as enzyme inhibitors against several enzymes. Our findings by docking and experimental studies that compound 7e is a potent CDK2 inhibitor with IC₅₀ of 0.149 µM, compared to the Roscovitine control drug with IC₅₀ of 0.380 µM. We also found that compound 8d is a significant DHFR inhibitor with an IC₅₀ of 0.199 µM, compared to Methotrexate control drug with IC₅₀ of 0.131 µM. Evaluation of the antioxidant properties of ten compounds was also studied in comparison with Vitamin C. Compounds 1, 3, 6, 7c and 8e have higher antioxidant activity than Vitamin C which mean that these compounds can used as potent antioxidant drugs.

Ethyl 5-cyano-1,6-dihydro-2-methyl-4-styryl-6-thioxonicotinate, its piperidinium pyridine-6-thiolate and 3-
acetyl-5-cyano-1,6-dihydro-2-methyl-4-styryl-6-thioxopyridine were used as starting materials for synthesizing
novel series of S-substituted methylthiopyridine-5-carbonitriles and thieno[2,3-b]pyridines with expected
biological activity. Also, some novel thieno[2,3-c][2,7]naphthyridinones were synthesized. Moreover, 1,7-
diamino-8,9-dihydro-5-methyl-8-phenyl-3H-pyrazolo[3,4-c][2,7]naphthyridine-6(7H)-one was synthesized by
heating ethyl 5-cyano-1,6-dihydro-2-methyl-4-styryl-6-thioxonicotinate with hydrazine hydrate 99% under
neat conditions. The obtained promising aminopyrazolo[3,4-c][2,7]naphthyridine-6(7H)-one was used as a
precursor to get other novel derivatives with expected biological and medicinal importance. Structures of all
new compounds were elucidated by elemental and spectral analysis.

Biopolymers are organic substances extracted from natural renewable sources, including plants, animals, and microorganisms. Chitin, the parent source of chitosan (CS), is the second most abundant natural biopolymer available in seafood-processing wastes and fungal cell walls. Pure and conjugated CS nanocomposites are extensively explored in environmental remediation, agriculture, food packaging, and biomedicine due to their affordability, superior heavy metals and dye chelation, biodegradability, flocculating, and film-forming and antimicrobial properties. CS reactive hydroxyl and amino groups enable surface functionalization for enhanced solubility over a wider range of pH, thermal stability, and mechanical strength. This chapter gives an overview on sources, extraction techniques, modifications, properties, and applications of CS.

In this study, two new thieno[2,3-b]pyridine derivatives (2 and 3) have been synthesized and characterized by single X-ray diffraction. While compound 2 crystallizes in monoclinic space group P2₁/c, compound 3 crystallizes in triclinic space group P. These compounds were further subjected to molecular docking simulation with p38 alpha MAP kinase to understand the binding interaction mechanism, in addition to that ADMET analysis was also performed to explore the title compounds to characterize the future drug candidate. To rationalize their structure-activity relationship, a DFT study based on the B3LYP/6-311++G** theoretical level was also done in this study.