Thiophene Moieties Research Articles

Enhancing perovskite solar cells performance through tailored design: pyridine-functionalized phenothiazine derivatives with modified end-capped acceptor moieties

Abstract Future energy resources are being developed using clean and renewable energies since these sources offer environmentally friendly and sustainable choices to traditional sources like fossil fuels. Among various renewable energy sources, solar energy is becoming increasingly efficient with advancements in organic photovoltaic systems. Organic semiconductor materials, which require high electron affinity and possess desirable optical and electronic properties, are crucial for these systems. Researchers are constantly trying to increase the role of photovoltaic materials in optoelectronic applications. With current energy demands, there is a shift from traditional solar cells to perovskite photovoltaic materials due to their significant contributions to renewable energy. Therefore, we have designed a new stream of donor- π -acceptor (D- π -A) type pyridine functionalized phenothiazine derivates-based donor materials, resulting in nine fabricated HTMs (PT1-PT9), by substituting the terminals with thiophene and acceptors moieties respectively to enhance the photovoltaic properties of perovskite solar cells (PSCs). All newly proposed materials were computationally examined to estimate their optoelectronics, geometrical, and photovoltaic properties using quantum chemical approach, and then compared to the reference. For organic hole-transporting materials, a heterocyclic phenothiazine core (PTZ) has been proven effective as it has feasible structure modifications, excellent electron-donating properties, and straightforward synthesis. The study of electronic parameters (density of state, frontier molecular orbitals, and electrostatic potential ESP), optical properties (light harvesting efficiency, absorption maxima, dipole moment, and first excitation energies) and charge transfer characteristics (electron–hole overlap, transition density matrix) of designed materials revealed that there is an increase in absorption range under the influence of terminal acceptor groups, with lowering the bandgap values compared to the reference. A density of state (DOS) graph and HOMO–LUMO schema are evidence of the electron-withdrawing effect of acceptor moieties. Transition density matrix (TDM) analysis proves reliable charger transfer in designed molecules. Reorganization energy values for designed molecules are lower than the reference making charge transfer carriers more efficient. Additionally, solvation-free energy values (−17.28 to −33.19 Kcalmol−1) and higher dipole moments suggest better surface-wetting and solubility properties. In general, the fabricated materials have exceptional charge mobilities with higher absorption and reduced band gap values that make them suitable and stable candidates for photovoltaic devices.

Novel benzothiophene‒tethered 1,3,4‒oxadiazoles as potent antimicrobial targets: Design, synthesis, biological evaluation, DFT exploration and in silico docking study

Based on previous developments of oxadiazole research programs in trying to find novel compounds with multiple biological targets, such as antibacterial and antitubercular medications. In the context, a new series of 1,3,4-oxadiazole derivatives based on benzo[b]thiophene moiety 6a‒d, 7a‒d, and 8a‒d was synthesized from 5-(3-methylbenzo[b]thiophen-2-yl)-1,3,4-oxadiazole-2-thiol. The structures of 1,3,4‒oxadiazole derivatives were elucidated via NMR (1H and 13C), IR, and HRMS spectrum data as well as physical data. Subsequently, the derivatives were evaluated for their inhibitory activity against different bacterial microorganisms, and the MICs were determined in vitro tubercular activity against the sensitive M. tuberculosis H37Rv strain. Remarkably, hybrids 6c and 7a exhibited excellent antibacterial activity against S. aureus with ZI values of 31 ± 0.99, and 30 ± 0.32 mm, and it has been noticed that 8b demonstrated the most prominent antibacterial efficiency with MICs = 3.1, 3.6, 5.6, and 5.1 μg/mL against S. pneumoniae, S. pyrogenes, E. coli, and K. pneumoniae. Among them, compound 8b, featuring a benzo[b]thiophene moiety linked to oxadiazole, exhibited a significant tubercular inhibitory effect with an MIC value of 2.2.5 μM. Additionally, the docked compound 7a showed the strongest key active key amino acids Arg44(A), Arg45(A), Ala126(A), Gly18(A), Ser49(A), Asp48(A) in the antitubercular active site of 1DG5 protein. The study of computer aided ADMET was also carried out, using SwissADME and ADMETlab2.0 to investigate the pharmacokinetic properties of the tested triazole compounds. To support the experimental data, molecular docking and density functional theory (DFT) studies help in understanding the interactions better.

One Pot Synthesis of Thiopyrimidine Derivatives from Lignin Reproductions by Microwave-Assisted Ultrasonic Microscopy with DFT Description for Clarifying the Mass Spectrum

In this work, an efficient and sustainable procedure for the one-pot synthesis of thiopyrimidine derivatives starting 1,3-diketone cut off β-O-4 lignin precursors to create anticancer agents. Microwave-ultrasonic assisted lignin extract in accessing various heterocyclic precursors such as pyrimidine, pyridine, and thiophene moieties. The results designated the ultrasonic-assisted microwave significantly accelerated synthesis with reduced time. We have diversely prolonged to tight-binding approaches to the electron ionization mass spectrometry with quantum stimulation (DFT/EIMS) to examine electron ionization mass spectra correlated to the experiment. Moreover, DFT/EIMS provides into the mechanism of the reaction of mass spectra trials. It cabins on the fragmentation method to raise the challenging bond breaking and structural rearrangements. The quantum chemical process for effective precursors of a mass spectrum is exactness required and discussed. Foremost fragmentation designs are studied and related to experimental data of the pyrimidin-thione derivatives and their glycosides.

Rational Design of Dual-Domain Binding Inhibitors for N-Acetylgalactosamine Transferase 2 with Improved Selectivity over the T1 and T3 Isoforms.

The GalNAc-transferase (GalNAc-T) family, consisting of 20 isoenzymes, regulates the O-glycosylation process of mucin glycopeptides by transferring GalNAc units to serine/threonine residues. Dysregulation of specific GalNAc-Ts is associated with various diseases, making these enzymes attractive targets for drug development. The development of inhibitors is key to understanding the implications of GalNAc-Ts in human diseases. However, developing selective inhibitors for individual GalNAc-Ts represents a major challenge due to shared structural similarities among the isoenzymes and some degree of redundancy among the natural substrates. Herein, we report the development of a GalNAc-T2 inhibitor with higher potency compared to those of the T1 and T3 isoforms. The most promising candidate features bivalent GalNAc and thiophene moieties on a peptide chain, enabling binding to both the lectin and catalytic domains of the enzyme. The binding mode was confirmed by competitive saturation transfer difference NMR experiments and validated through molecular dynamics simulations. The inhibitor demonstrated an IC50 of 21.4 μM for GalNAc-T2, with 8- and 32-fold higher selectivity over the T3 and T1 isoforms, respectively, representing a significant step forward in the synthesis of specific GalNAc-T inhibitors tailored to the unique structural features of the targeted isoform.

New cyano-acrylamide derivatives incorporating the thiophene moiety: Synthesis, anti-cancer, gene expression, DNA fragmentation, DNA damage, and in silico studies

New cyano-acrylamide derivatives bearing the thiophene structure were prepared and rigorously characterized. Thus, the reaction of diethyl 5-(2-cyanoacetamido)-3-methylthiophene-2,4-dicarboxylate with aldehydes in the presence of piperidine afforded the title compounds in very good to excellent yields (range 81-96%, mean 91%). All the newly synthesized compounds were evaluated as anti-cancer agents against five human cancer cell lines namely, MCF7 (human Caucasian breast adenocarcinoma), PC3 (human prostate cancer cell line), HepG2 (Human hepatocellular carcinoma), PACA2 (epithelial cell line derived from tumor tissue of pancreas), and BJ1 (normal skin fibroblast). While most of the compounds showed good activity against MCF-7, they showed limited activity against PC3, HepG2, and PACA2. Compound 9 showed potent anti-cancer activity against the PACA2 cell line with IC50 131.18 µM compared with the reference drug (doxorubicin, IC50 52.06 µM), while compound 10 exhibited potent anti-cancer activity against HePG2 cell lines with IC50 24.51 µM compared to the positive control (doxorubicin, IC50 39.73 µM). The gene expression, DNA fragmentation, and DNA damage of the most promising compounds were discussed. Additionally, compounds 9 and 10 showed favorable binding energies and strong interactions with CDK2, EGFR, ERα, VEGFFR, and Topoisomerase II receptors in the molecular docking simulation. These results suggest that these compounds have the potential to be effective candidates for anti-cancer therapy. Additionally, the in-silico ADMET profiles indicated that these compounds adhere to the Lipinski rules, indicating favorable physicochemical properties. These findings further support their potential for continued drug development efforts.

“Thiophene”: A Sulphur Containing Heterocycle as a Privileged Scaffold

: In the rapidly expanding chemical realm of heterocyclic compounds with interesting therapeutic properties, the thiophene nucleus has established itself as a prospective entity. The biological activity of comparable substances produced via different pathways is of varying magnitudes. Medicinal chemists use their understanding of multiple synthetic pathways and the various physicochemical properties of such compounds to create a combinatorial library and conduct thorough searches for lead molecules. Due to their vast spectrum of biological actions, heterocyclic compounds play a crucial role in Medicinal chemistry and are extensively researched in the field of drug design and development. Thiophene, a sulfur- containing heterocyclic scaffold, has emerged as a rather well-explored scaffold for the synthesis of a library of molecules with biological functions, including antibacterial, antipsychotic, anticancer, analgesic, anti-inflammatory, anti-arrhythmic, and so on. Depending on the kind and position of substitution, thiophene analogues have been shown to bind to a wide spectrum of cancer-specific protein targets. As a result, thiophene analogues have been found to exert their biological effects by inhibiting various cancerrelated signalling pathways. The study of thiophene in Medicinal chemistry resulted in molecules that combine the thiophene moiety with traditional drug components in a single molecule. This review covers the biological and medical activity of compounds containing a thiophene nucleus, as well as information on thiophene behaviour, synthesis, and agents, with a focus on synthetic techniques, biological profiles, and structure-activity relationship (SAR) research.

Mechanistic insights into a heterobifunctional degrader-induced PTPN2/N1 complex

PTPN2 (protein tyrosine phosphatase non-receptor type 2, or TC-PTP) and PTPN1 are attractive immuno-oncology targets, with the deletion of Ptpn1 and Ptpn2 improving response to immunotherapy in disease models. Targeted protein degradation has emerged as a promising approach to drug challenging targets including phosphatases. We developed potent PTPN2/N1 dual heterobifunctional degraders (Cmpd-1 and Cmpd-2) which facilitate efficient complex assembly with E3 ubiquitin ligase CRL4CRBN, and mediate potent PTPN2/N1 degradation in cells and mice. To provide mechanistic insights into the cooperative complex formation introduced by degraders, we employed a combination of structural approaches. Our crystal structure reveals how PTPN2 is recognized by the tri-substituted thiophene moiety of the degrader. We further determined a high-resolution structure of DDB1-CRBN/Cmpd-1/PTPN2 using single-particle cryo-electron microscopy (cryo-EM). This structure reveals that the degrader induces proximity between CRBN and PTPN2, albeit the large conformational heterogeneity of this ternary complex. The molecular dynamic (MD)-simulations constructed based on the cryo-EM structure exhibited a large rigid body movement of PTPN2 and illustrated the dynamic interactions between PTPN2 and CRBN. Together, our study demonstrates the development of PTPN2/N1 heterobifunctional degraders with potential applications in cancer immunotherapy. Furthermore, the developed structural workflow could help to understand the dynamic nature of degrader-induced cooperative ternary complexes.

Post-Functionalization of Thiophene-Fluorene Alternating Copolymers via Anodic Phosphonylation

Phosphonylated polymers are promising materials because of their application in sensor chemistry and their unique electronic properties. Among these polymers, conjugated polymers containing dialkylphosphonate at their side chains have been used in chemical sensors1 and exhibit unique electronic properties.2 However, there have been a few reports on phosphonylation into the conjugated polymer main chains except for poly(3-hexylthiophene) (P3HT)3 and polyaniline derivatives,4 demonstrating that the effect of phosphonate on their main chains has been unclear. To introduce the phosphonate into their main chains, electrochemical post-functionalization is an attractive approach because of the simple protocol and mild reaction conditions.5 Recently, anodic phosphonylation of P3HT at the main chains with trialkyl phosphite was reported.3 However, the applicable precursor polymer is limited to P3HT. Furthermore, the substitution degree was quite low (0.25), indicating that it is necessary to be improved for establishment.Here, to expand applicable precursor polymers and improve the substitution degree, anodic phosphonylation of thiophene–fluorene alternating copolymers (P(Fl-Th)) was conducted (Figure 1), and then we obtained the phosphonylated conjugated polymer (P(Fl-Th-phos(Et)) (substitution degree: 0.26). The obtained polymer showed that phosphonate was introduced selectively into electron-rich thiophene rings. However, the substitution degree was still low. When a 2,6-lutidine was added to the reaction solution, the substitution degree was increased up to 0.83. Furthermore, the substitution degree could be controlled by tuning the amount of charge passed, and the optoelectronic properties of P(Fl-Th-Phos(Et)) were gradually changed through control of the substitution degree. In addition, it was found that various trialkyl phosphite were available in anodic phosphonylation.To functionalize the fluorene units, we carried out anodic phosphonylation of P(Fl-EDOT) which was di-substituted at thiophene moieties, and then the degree of phosphonylation reached 0.75 under the constant-current condition. On the other hand, when we performed constant-potential anodic phosphonylation of P(Fl-EDOT), the substitution degree was improved up to 0.98, indicating that the use of constant-potential electrolysis enabled quantitative anodic phosphonylation.These results demonstrate that anodic phosphonylation can be applied to versatile π-conjugated polymers and that the position of phosphonate introduction can be controlled through the design of appropriate precursor polymers. In addition, due to two alkyl chains, the phosphonate group could enable further modification such as side-chain engineering of conjugated polymers.References G. Zhou, G. Qian, L. Ma, Y. Cheng, Z. Xie, L. Wang, X. Jing, F. Wang, Macromolecules, 2005, 38, 5416–5424.J. Hopkins, K. Fidanovski, L. Travaglini, D. Ta, J. Hook, P. Wagner, K. Wagner, A. Lauto, C. Cazorla, D. Officer, D. Mawad, Chem. Mater., 2022, 34, 140–151.K. Taniguchi, T. Kurioka, N. Shida, I. Tomita, S. Inagi, Polym. J., 2022, 54, 1171–1178.T. Amaya, I. Kurata, Y. Inada, T. Hatai, T. Hirao, RSC Adv., 2017, 7, 39306–39313.T. Kurioka, S. Inagi, Chem. Rec., 2021, 21, 2107–2119. Figure 1

New Analogues of the Nicotinamide Phosphoribosyltransferase Inhibitor FK866 as Potential Anti-Pancreatic Cancer Agents.

During the past two decades, many nicotinamide phosphoribosyltransferase (NAMPT) inhibitors were prepared and tested because this enzyme is overexpressed in pancreatic cancer. Although FK866 is a well-known, strong NAMPT inhibitor, it suffers severe drawbacks. Our work aimed to synthesize efficient NAMPT inhibitors featuring better pharmacokinetic properties than the pyridine-containing FK866. To this aim, the new anticancer agents were based on benzene, pyridazine, or benzothiazole moieties as a cap group instead of the pyridine unit found in FK866 and other NAMPT inhibitors. The new compounds, prepared exploiting standard heterocycle chemistry and coupling reactions (e.g., formation of amides, ureas, and cyanoguanidines, copper-mediated azide-alkyne cycloaddition), have been fully characterized using NMR and HRMS analyses. Their activity has been evaluated using cytotoxicity and intracellular NAD depletion assays in the human pancreatic cancer cell line MiaPaCa-2. Among the 14 products obtained, compound 28, bearing a pyridazine unit as the cap group and a thiophene moiety as the tail group, showed 6.7 nanomolar inhibition activity in the intracellular NAD depletion assay and 43 nanomolar inhibition in the MiaPaCa-2 cells cytotoxicity assay, comparable to that observed for FK866. The positive results observed for some newly synthesized molecules, particularly those carrying a thiophene unit as a tail group, indicate that they could act as in vivo anti-pancreatic cancer agents.

The influence of metal-free thiophene spacer chain on optoelectronic analysis by TD-DFT method for efficient dye-sensitized solar cells with enhanced non-linear optical activity

The pyrene group in conjugation with the thiophene moiety was used to design new organic molecules for the dye-sensitized solar cells (DSSCs) along with non-linear optical (NLO) properties. Five new thiophene chain conjugation molecules (PTRA-SPn, n = 1–5) were formed based on the (E)-2-(5-oxo-4-((5-(pyren-1-yl)thiophen-2-yl)methylene)-2-thioxothiazolidin-3-yl)acetic acid (PTRA). To comprehend the function of conjugation in varying the optoelectronic characteristics of these compounds, the π-spacer chain has been screened. The techniques of density functional theory (DFT) and time-dependent DFT (TD-DFT) have been used to study the electronic structures, Ultraviolet–Visible (UV–Vis) absorptions, and NLO activities of donor-spacer-acceptor (D-π-A) structures. According to the computed results, PTRA-SP5 exhibits a smaller energy gap (Eg) of 2.11 eV. The maximum UV–Vis spectrum has been found in PTRA-SP5 with a wavelength (λmax) of 532 nm. The reorganizational energy (RE) and dye regeneration (ΔGreg) of PTRA-SP5 are the smallest (λ- = 0.2340 eV, λ+ = 0.2122 eV, ΔGreg = 0.21 eV) compared to other sensitizers. The lowest exciton binding energies (Eb) of PTRA-SP2 (0.06 eV) and PTRA-SP3 (0.06 eV) are the lowest ones. The open circuit photovoltage (eVoc) for PTRA-SP5 (1.10 eV) is the highest. The NLO activity of the dipole moment (μnormal) and first-order hyperpolarizability (β) values of PTRA-SP5 achieve higher values (9.00 Debye and 34.82 × 10−30 esu, respectively). In summary, this work refined the impact of chain π-linkers on the photophysical characteristics of D-π-A spacer derivatives and offered some helpful suggestions to create new organic materials for optoelectronic uses.

Quamtum Mechanical Study on Structural and Electronic Properties of Tert-Butyl Based Bridged Dithiophene Oxide Derivatives

Computational modeling is vital to designing and creating organic semiconductors used in solar cells, organic field-effect transistors, and other areas. This work studied the structural and electronic features of a group of substituted tert-butyl bridged dithiophene oxide derivatives using Density Functional Theory (DFT) calculations. Geometry improvements were carried out using the B3LYP hybrid functional and the 6-31G(d,p) basis set in Gaussian 09. Molecular shapes, bond lengths, bond angles, and dihedral angles were studied to find out how substitution patterns change the packing and conformation of molecules. Energy levels, distribution, and makeup of frontier molecular orbitals were found. This calculation also included finding other electronic qualities, such as electronic charges, dipole moments, and polarizabilities. Findings show that tert-butyl substitution makes the molecular backbone stiffer and limits its ability to twist compared to similar molecules that have not been replaced. The chemical geometry stays mostly the same when electron-withdrawing or electron-donating substituents are added to the tert- butyl groups. Nevertheless, the strength and location of substituents have a significant impact on frontier orbital energies. The HOMO-LUMO gap grew significantly when the nitro or cyano groups firmly pulled electrons away from derivatives. For successful charge transport, electron density plots show that the HOMO and LUMO are mainly located on the thiophene and substituent moieties, respectively. Molecular dipole moments are also strongly affected by the electronic features of substituents. This research shows how to change the optoelectronic properties of tert-butyl-based dithiophene oxide derivatives and how their structure-property relationships can be improved. The results help makes new organic semiconductors that work better in various electronic and optoelectronic uses.

Micelle-modulated ribonuclease-like activities of oxo-bridged binuclear copper(ii) complexes with novel imidazole derivatives

Three bis-tridentate imidazole derivatives as ligands and their alkoxo-bridged binuclear copper(II) complexes (1, 2 and 3) were synthesized and characterized. Single crystals show that furan or thiophene moiety of 2 or 3 is free without a coordination with the central copper. Five-coordinated structure of 1 is constructed via two Cu-N and three Cu-O coordination bonds involving the participation of phenolic oxygen, alkoxo-bridged oxygen and the one carboxylate oxygen. Furthermore, catalytic reactivity of the as-synthesized binuclear complexes was evaluated for the transesterification of classic RNA model HPNP (2-hydroxypropyl-4-nitrophenyl phosphate). Overall, three complexes displayed the almost similar activity in both non-micellar and micellar solutions. HPNP transesterification achieved more obvious acceleration in micellar solutions of three kinds of cationic surfactants. All of three complexes obtained relatively good reactivity in CTAB micellar solution, respectively achieving approximately 804-fold (for 1), 762-fold (for 2) and 785-fold (for 3) rate enhancement compared to background rate of HPNP spontaneous cleavage. The as-synthesized binuclear complexes displayed approximately two times dominative activity in CTAB micellar solution over that in the non-micellar system. However, to some extent the introduction of amphoteric n-lauroylsarcosine sodium (LSS) and non-ionic polyoxyethylene lauryl ether (Brij35) inhibited the catalytic transesterification of HPNP. This study is beneficial to the design and application of novel mimic esterolases.

Synthesis, cytotoxicity, anti-inflammatory, anti-metastatic and anti-oxidant activities of novel chalcones incorporating 2-phenoxy-N-arylacetamide and thiophene moieties: induction of apoptosis in MCF7 and HEP2 cells.

Eight Novel chalcones were synthesized and their structures were confirmed by different spectral tools. All the prepared compounds were subjected to SRB cytotoxic screening against several cancer cell lines. Compound 5c exerted the most promising effect against MCF7 and HEP2 cells with IC50 values of 9.5 and 12 µg/mL, respectively. Real-time PCR demonstrated the inhibitory effect of compound 5c on the expression level of Antigen kiel 67 (KI-67), Survivin, Interleukin-1beta (IL-1B), Interleukin-6 (IL-6), Cyclooxygenase-2 (COX-2) and Protein kinase B (AKT1) genes. Flow-cytometric analysis of the cell cycle indicated that compound 5c stopped the cell cycle at the G0/G1 and G2/M phases in MCF7 and HEP2 treated cells, respectively. ELISA assay showed that Caspase 8, Caspase 9, P53, BAX, and Glutathione (GSH) were extremely activated and Matrix metalloproteinase 2 (MMP2), Matrix metalloproteinase 9 (MMP9), BCL2, Malondialdehyde (MDA), and IL-6 were deactivated in 5c treated MCF7 and HEP2 cells. Wound healing revealed that chalcone 5c reduced the ability to close the scrape wound and decreased the number of migrating MCF7 and HEP2 cells compared to the untreated cells after 48 h. Theoretical molecular modeling against P53 cancer mutant Y220C and Bcl2 showed binding energies of -22.8 and -24.2 Kcal/mole, respectively, which confirmed our ELISA results.

Structural evolution during inverse vulcanization

Inverse vulcanization exploits S8 to synthesize polysulfides. However, evolution of products and its mechanism during inverse vulcanization remains elusive. Herein, inverse vulcanization curves are obtained to describe the inverse vulcanization process in terms of three stages: induction, curing and over-cure. The typical curves exhibit a moduli increment before declining or plateauing, reflecting the process of polysulfide network formation and loosing depending on monomers. For aromatic alkenes, in the over-cure, the crosslinked polysulfide evolves significantly into a sparse network with accelerated relaxation, due to the degradation of alkenyl moieties into thiocarbonyls. The inverse vulcanization product of olefins degrades slowly with fluctuated relaxation time and modulus because of the generation of thiophene moieties, while the inverse vulcanization curve of dicyclopentadiene has a plateau following curing stage. Confirmed by calculations, the mechanisms reveal the alkenyl groups react spontaneously into thiocarbonyls or thiophenes via similar sulfur-substituted alkenyl intermediates but with different energy barriers.

A Thiophene Functionalized Hf(IV)-Organic Framework for the Detection of Anti-Neoplastic Drug Flutamide and Biomolecule Hemin and Catalysis of Friedel-Crafts Alkylation.

Development, rapid detection and quantification of anticancer drugs in biological samples are crucial for effective drug monitoring. The present work describes the design of a Hf(IV)-based metal-organic framework (MOF) (1) by the reaction between Hf(IV) ion and 2-(thiophene-2-carboxamido)terephthalic acid linker with the surface area of 571 m2 g-1. Desolvated MOF (1') displayed highly discriminative fluorescence sensing properties for the antineoplastic drug flutamide and biomolecule hemin in an aqueous medium in the presence of co-existing biomolecules and ions. The MOF's response time for sensing flutamide and hemin was less than 5 s with low detection limits of 1.5 and 0.08 nM, respectively. Additionally, 1' also demonstrated recyclability up to five cycles and maintained its sensing ability across different pH media, various water samples, and biological fluids. Experimental and theoretical analyses suggested photoinduced electron transfer and inner-filter effect in the presence of flutamide and Förster resonance energy transfer in the presence of hemin are most likely reasons behind the fluorescence quenching of MOF. Furthermore, the MOF demonstrated catalytic activity in Friedel-Crafts alkylation reactions, providing a 96 % yield with slight decay in its activity over four uses. The enhanced activity of 1' compared to Hf-BDC and Hf-BDC-NH2 (BDC: 1,4-benzenedicarboxylic acid) is due to the functionalized thiophene moieties through hydrogen bond donating sites, confirmed by a series of control experiments.

Convenient synthesis and characterization of new 1,3,4-thiadiazoles and thiazoles incorporating thiophene moiety

Convenient synthesis and characterization of new 1,3,4-thiadiazoles and thiazoles incorporating thiophene moiety

Iron‐Catalyzed C−C and C−N Bond‐Forming Tandem Amidation Offering Access to 3‐Amino‐3‐Aminomethyl‐2‐Oxindole Frameworks

AbstractAn iron‐catalyzed protocol for the synthesis of 3‐amino‐3‐aminomethyl‐2‐oxindole heterocyclic structures is disclosed employing isatins and non‐nucleophilic N‐methoxybenzamides. This reaction class is associated with broad scope and tolerates numerous functionalities, such as fluoro, chloro, bromo, iodo, trifluoromethyl, nitrile, ester, ether, and alkenyl, including heteroaryl – thiophene, benzothiophene, carbazolyl, indolyl, eugenol, and polycyclic cholesterol moieties. Detailed mechanistic investigations reveal that the reaction proceeds via iron‐catalyzed N−O bond cleavage in N‐methoxybenzamides, generating formaldehyde and benzamide, and through the intermediacy of isatin‐ketimines and N‐(hydroxymethyl)benzamides. Overall, this amidation reaction involves one C−C and two C−N bond‐forming tandem processes, providing a range of β‐amino‐aminomethyl‐oxindoles (45 examples) in up to 88% yields.

An All‐Rounder for NIR‐II Phototheranostics: Well‐Tailored 1064 nm‐Excitable Molecule for Photothermal Combating of Orthotopic Breast Cancer

AbstractThe second near‐infrared (NIR‐II, 1000–1700 nm) light‐activated organic photothermal agent that synchronously enables satisfying NIR‐II fluorescence imaging is highly warranted yet rather challenging on the basis of the overwhelming nonradiative decay. Herein, such an agent, namely TPABT‐TD, was tactfully designed and constructed via employing benzo[c]thiophene moiety as bulky electron donor/π‐bridge and tailoring the peripheral molecular rotors. Benefitting from its high electron donor–acceptor strength and finely modulated intramolecular motion, TPABT‐TD simultaneously exhibits ultralong absorption in NIR‐II region, intense fluorescence emission in the NIR‐IIa (1300–1500 nm) region as nanoaggregates, and high photothermal conversion upon 1064 nm laser irradiation. Those intrinsic advantages endow TPABT‐TD nanoparticles with prominent fluorescence/photoacoustic/photothermal trimodal imaging‐guided NIR‐II photothermal therapy against orthotopic 4T1 breast tumor with negligible adverse effect.

An All-Rounder for NIR-II Phototheranostics: Well-Tailored 1064 nm-Excitable Molecule for Photothermal Combating of Orthotopic Breast Cancer.

The second near-infrared (NIR-II, 1000-1700 nm) light-activated organic photothermal agent that synchronously enables satisfying NIR-II fluorescence imaging is highly warranted yet rather challenging on the basis of the overwhelming nonradiative decay. Herein, such an agent, namely TPABT-TD, was tactfully designed and constructed via employing benzo[c]thiophene moiety as bulky electron donor/π-bridge and tailoring the peripheral molecular rotors. Benefitting from its high electron donor-acceptor strength and finely modulated intramolecular motion, TPABT-TD simultaneously exhibits ultralong absorption in NIR-II region, intense fluorescence emission in the NIR-IIa (1300-1500 nm) region as nanoaggregates, and high photothermal conversion upon 1064 nm laser irradiation. Those intrinsic advantages endow TPABT-TD nanoparticles with prominent fluorescence/photoacoustic/photothermal trimodal imaging-guided NIR-II photothermal therapy against orthotopic 4T1 breast tumor with negligible adverse effect.

Employing acetoacetamide as a key synthon for synthesizing novel thiophene derivatives and assessing their potential as antioxidants and antimicrobial agents

AbstractThe objective of this study is to synthesize novel heterocyclic scaffolds containing a thiophene moiety using easily accessible acetoacetamide as a key synthon. The reaction of acetoacetamide with diazonium salts resulted in the formation of the corresponding thiophene derivatives 4a–c. Additionally, the reaction of acetoacetamide derivative 3 with malononitrile, ethyl cyanoacetate, or 2‐cyanoacetamide, along with elemental sulfur, under refluxing in dioxane containing triethylamine afforded thiophene‐containing derivatives 5a–c. Furthermore, compound 3 reacted with phenyl isothiocyanate in dry dimethylformamide and K2CO3 to yield compound 7. In situ alkylation of the non‐isolable salt 6 was achieved by the addition of methyl iodide, resulting in the formation of methylthio‐thiophene‐2‐carboxamide 8. Compound 7 was employed with numerous alpha‐halogenated reagents in ethanol, affording thiazole derivative 9 and thiophene derivatives 10a and 10b, respectively. Moreover, compound 8 was reacted with hydrazine to produce the 1H‐pyrazole‐4‐carboxamide derivative 11. Additionally, refluxing acetoacetamide derivative 3 with malononitrile and/or ethyl cyanoacetate in dioxane, in the presence of catalytic amount of triethylamine afforded 4‐imino‐3,7‐dimethyl‐4H‐pyrido[1,2‐a]thieno[3,2‐e]pyrimidin‐9(5H)‐one derivatives 12a and 12b. Furthermore, the reactivity of acetoacetamide derivative 3 with 2‐cyanoacetohydrazide was investigated through refluxing the reactants in dioxane, which subsequently yielded the corresponding cyanoacetamide derivative 13. The chemical identity of the newly synthesized compounds was determined by employing infrared spectroscopy (IR), 1H NMR, and 13C NMR techniques. Newly synthesized heterocycles incorporating thiophenes were evaluated for their antioxidant and antimicrobial potentials. Notably, thiophene scaffolds 5a, 10b, 11, and 13 displayed notable antioxidant and antimicrobial activities.