Organic Chemistry Research Articles

An Exceptional Valorization of CuO Nanoparticles in Ionic Liquids as an Efficient Medium for the Electrophilic Substitution of Indole Towards the Formation of Bis(indolyl)methanes

Aim: Ionic liquids are promising green solvents with simple but unique structure-related physical properties such as negligible vapour pressure, exceptional thermal conductivity, remarkable thermal stability and their suitability and inertness towards a broad range of catalytic applications. CuO NPs have been addressed as a cost-effective and a reagent of a choice that necessitates only mild reaction conditions to offer a high yield of the desired products with exceptional selectivity in a short duration of time. Therefore, in the present work, attempts have been made to explore the catalytic potentials of CuO NPs in an ionic liquid medium to synthesize biologically important bis(indolyl)methanes. Background: Catalytic explorations of metal oxide nanoparticles in ionic liquids offers a cooperative effect that has a significant impact on the kinetics as well as on the outcome of the reaction. Therefore, such catalytic systems in the present times have seized the scientific community's interest from the perspectives of sustainable development in synthetic organic chemistry. The combination of metal oxide nanoparticles with highly tunable ionic liquids is not only used to synthesize simple organic molecules but also explored in the synthesis of complex organic molecules of high commercial and biological relevance. Objectives: The current work offers a rapid and robust protocol for synthesizing bis(indolyl)methanes via electrophilic substitution reaction between indole and various aldehydes in the presence of a CuO nanoparticles-ionic liquid system. The discussion focuses on the high tolerance of different functionalities by the catalytic system leading to the synthesis of bis(indolyl)methanes. Methods: CuO NPs have been synthesized via the co-precipitation method using ionic liquid. The applicability of metal oxide nanoparticles-IL matrix was further investigated in synthesizing bis(indolyl)methanes. Results: The FT-IR absorption below 600 cm-1 and the XRD pattern showing all the peaks in the diffraction diagram revealed the formation of CuO NPs. FESEM images show the flake-shaped morphology of CuO NPs and are found to be separated from the agglomerated clusters Conclusion: Ionic liquid-CuO NPs matrix reveals good to exceptional catalytic properties, and their advancements as a catalytic system at room temperature open new avenues for synthetic organic chemists.

Organic Chemistry and its Important Role in the Creation of Type: Novel Functional Materials

Organic Chemistry and its Important Role in the Creation of Type: Novel Functional Materials

Musk and the Making of Macromolecules: Perfumes and Polymers in the History of Organic Chemistry

Musk and the Making of Macromolecules: Perfumes and Polymers in the History of Organic Chemistry

A Decennial Update on the Applications of Trifluroacetic Acid

Abstract: Since its discovery at the beginning of the 20th century, trifluoroacetic acid, commonly known as TFA, has seen extensive application in organic synthesis both as a solvent and as a catalyst/ reagent. TFA can be used to facilitate a wide variety of chemical transformations, including rearrangements, functional group deprotections, condensations, hydroarylations and trifluoroalkylations, among others. The decennial mini-review examines key TFA synthetic applications from the middle of 2013 to the present, providing the organic chemistry research community with an opportunity to delve deeply into the numerous and varied applications of this strong acid, water-miscible, and low boiling point reagent.

Recent Progress on Synthesis of Functionalized 1,5-Disubstituted Triazoles.

Immediately after the invention of 'Click Chemistry' in 2002, the regioselective 1,2,3- triazole scaffolds resulted from respective organic azides and terminal alkynes under Cu(I) catalysis have been well recognized as the functional heterocyclic core at the centre of modern organic chemistry, medicinal chemistry, and material sciences. This CuAAC reaction has several notable features including excellent regioselectivity, high-to-excellent yields, easy to execute, short reaction time, modular in nature, mild condition, readily available starting materials, etc. Moreover, the resulting regioselective triazoles can serve as amide bond isosteres, a privileged functional group in drug discovery and development. More than hundreds of reviews had been devoted to the 'Click Chemistry' in special reference to 1,4-disubstituted triazoles, while only little efforts were made for an opposite regioisomer i.e., 1,5-disubstituted triazole. Herein, we have presented various classical approaches for an expeditious synthesis of a wide range of biologically relevant 1,5- disubstituted 1,2,3-triazole analogues. The syntheses of such a class of diversly functionalized triazoles have emerged as a crucial investigation in the domain of chemistry and biology. This tutorial review covers the literature assessment on the development of various synthetic protocols for the functionalized 1,5-disubstituted triazoles reported during the last 12 years.

Study on Sustainable Resource Utilization as Ligand Precursors in Coordination Chemistry

Ligand Precursors in Coordination Chemistry.” Sustainable resource utilization in ligand precursor synthesis is crucial for advancing green chemistry principles and addressing environmental concerns in coordination chemistry. This study investigates the feasibility and efficacy of utilizing renewable resources as precursor materials for ligand synthesis, aiming to reduce environmental impact while maintaining the efficacy and versatility required in coordination chemistry applications. Through a combination of synthetic organic chemistry and coordination chemistry techniques, novel ligand precursors derived from sustainable sources were synthesized and characterized. Various renewable feedstocks, including biomass-derived compounds and waste materials, were explored as potential starting materials for ligand precursor synthesis. Optimization of synthetic routes and reaction conditions led to the development of efficient protocols for the synthesis of sustainable ligand precursors. Characterization techniques such as nuclear magnetic resonance spectroscopy, mass spectrometry, and infrared spectroscopy were employed to confirm the structures and purities of synthesized ligand precursors. Evaluation of the performance of sustainable ligand precursors in coordination chemistry reactions demonstrated their ability to form stable complexes with metal ions and exhibit catalytic activity in relevant reactions. Comparative studies with traditional ligands revealed the environmental advantages of sustainable ligand precursors, including reduced energy consumption, greenhouse gas emissions, and solvent usage. Overall, this study highlights the importance of sustainable resource utilization in ligand precursor synthesis for promoting environmentally friendly practices in coordination chemistry and advancing the principles of green chemistry.

Terpenoids of plants from Chloranthaceae family: chemistry, bioactivity, and synthesis.

Covering: 1976 to December 2023Chloranthaceae is comprised of four extant genera (Chloranthus, Sarcandra, Hedyosmum, and Ascarina), totaling about 80 species, many of which have been widely used as herbal medicines for diverse medical purposes. Chloranthaceae plants represent a rich source of structurally interesting and diverse secondary metabolites, with sesquiterpenoids and diterpenoids being the predominant structural types. Lindenane sesquiterpenoids and their oligomers, chemotaxonomical markers of the family Chloranthaceae, have shown a wide spectrum of bioactivities, attracting significant attention from organic chemists and pharmacologists. Recent achievements also demonstrated the research value of two unique structural types in this plant family, sesquiterpenoid-monoterpenoid heterodimers and meroterpenoids. This review systematically summarizes 682 structurally characterized terpenoids from 22 Chloranthaceae plants and their key biological activities as well as the chemical synthesis of selected terpenoids.

Molecular Weight-Dependent Physiochemical Behaviors of Calcium Carbonate Chains.

The regulation of physiochemical behaviors by changing molecular weights is an important cornerstone of polymer physics. However, similar correlations between molecular weights and properties have not been discovered in inorganic ionic compounds. In this work, we prepared a calcium carbonate specimen with a semiflexible chain topology analogous to those of polymers. The molecular weights of the calcium carbonate chains, which ranged from 3400 to 54 100 Da, were directly correlated to their physiochemical behaviors, including gel point, zero shear viscosity, and plateau modulus. The calcium carbonate chains showed similar polymeric characteristics, including shear thinning, thixotropy, entropic elasticity, and viscoelasticity. These features agreed with recent theories and formulas in polymer physics textbooks. On the basis of this understanding, the mechanical properties of calcium carbonate-based gels could be altered by changing their molecular weights. This study could represent a fusion of inorganic chemistry and polymer physics with similar molecular weight-dependent behaviors and material properties, establishing an alternative pathway for designing future inorganic materials.

Highly Selective Ratiometric Sensors for Pb2+ Based on Luminescent Zn(II)-Coordination Polymers with Thiophenedicarboxylate. Crystal Structures and Spectroscopic Studies.

The development of luminescent coordination polymers for the selective sensing of Pb2+ in water constitutes an active area of research that impacts analytical, environmental, and inorganic chemistry. Herein, two novel water-stable 2D Zn-coordination polymers {[Zn2(H2O)2(tdc)2(bpy)]·(H2O)}n 1 and [Zn(tdc)(tmb)]n 2 (tdc = thiophenedicarboxylate; bpy = 4,4'-bipyridine and tmb = 4,4'-trimethylenebipyridine) were synthesized, structurally determined by single crystal X-ray diffraction, and studied in-depth as luminescent sensors for a series of cations (Ca2+, Mg2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+ Cd2+, Hg2+ and Pb2+) in 20% aqueous ethanol. These Zn-polymers possess photostability in 20% aqueous ethanol with a strong emission at 410 upon excitation at 330nm and quantum yields of around Φ = 0.09. Under these conditions, Pb+2 can be efficiently sensed with polymer 2 through a fluorescent ratiometric response with selectivity over common interfering metal ions such as Cu2+, Cd2+ and Hg2+ in the micromolar concentration range (detection limit = 1.78 ± 10μM). Such selectivity/affinity of Pb2+ over Hg2+ for luminescent chemosensors is still rare. On the basis of spectroscopic tools (1H NMR, far ATR-IR, PXRD), the X-ray crystal structure of 2, and Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopic analysis, the ratiometric fluorescent response is proposed via an efficient metal-ion exchange driven through interactions between thiophenedicarboxylate rings and Pb2+ ions. The use of flexible luminescent Zn-coordination polymers as sensors for selective and direct detection of Pb2+ in aqueous media has been unexplored until now.

Catalysis for Carbon-Circularity: Emerging Concepts and Role of Inorganic Chemistry.

Carbon circularity is crucial for achieving a circular economy but has wider implications and impacts with respect to the circularity of materials. It has an in-depth transformative effect on the economy. CO2 recycling is a critical component for this objective, with catalysis and inorganic chemistry playing a determining role in achieving this challenge. This concept paper presents some examples, as food for thought, of unconventional aspects in developing thermal and electro/photocatalysts for recycling CO2. The aspects discussed regard designing novel materials for CO2 thermo- or electro-conversion and developing novel nanostructured electrodes.

Quantitative liquid storage by billiards‐like droplet collision on surfaces with patterned wettability

AbstractThere has been significant interest in researching droplet transport behavior on composite wetting surfaces. However, current research is primarily focused on modifying individual droplets and lacks an in‐depth investigation into high‐precision droplet storage. This study introduces a “billiard ball” droplet transport and storage platform (TSP) with differentiated areas. Within this platform, the volume of droplets stored in the area reaches a consistent threshold through droplet “scrambling,” inspired by the water‐gathering behavior of spiders. The TSP involves connecting two regions of different sizes using a three‐dimensional stepped wedge angle structure. However, this connection is not seamless, leaving a 2‐mm gap between the regions. This gap is intentionally designed to enable continuous droplet transfer while preventing any static migration. Through systematic experimental and simulation analysis, we investigated the influence of superhydrophilic pattern structures and parameters on quantitative droplet storage. We established a functional relationship between the pattern area and the stored volume, and analyzed the intrinsic mechanism of droplet collision separation. This enabled us to achieve on‐demand quantitative droplet storage and autonomize the storage process. The “billiard ball” droplet transport–storage platform proposed in this study holds promising applications in the fields of biomedical and organic chemistry.

Two-Dimensional Cu(II)-MOF with Lewis Acid-Base Bifunctional Sites for Chemical Fixation of CO2 and Bioactive 1,4-DHP Synthesis via Hantzsch Condensation.

Five- and six-membered heterocycles containing nitrogen or oxygen have been considered as privileged scaffolds in organic chemistry and the chemical industry because of their usage in high-value commodities. Herein, we report a two-dimensional (2D) Cu(II)-based MOF catalyst, IITKGP-40, via the strategic employment of ample Lewis acid-base bifunctional sites (open metal nodes and free pyrazine moieties) along the pore wall. IITKGP-40 could convert toxic CO2 to cyclic carbonates in an atom-economical manner under solvent-free conditions and aromatic aldehyde to bioactive 1,4-DHPs via Hantzsch condensation. Exceptional catalytic performance (99%) and turnover number under mild reaction conditions for CO2 fixation using sterically hindered styrene oxide, and good-to-excellent yields for a wide range of aromatic aldehydes toward 1,4-dihydropyridines (1,4-DHPs) make IITKGP-40 promising as a multipurpose heterogeneous catalyst. Moreover, to demonstrate the practical utility of the catalyst, two biologically important drug molecules, diludine and nitrendipine analogue, have also been synthesized. IITKGP-40 is recyclable for at least three consecutive runs without significant loss of activity, making it promising for real-time applications.

NMR spectroscopic investigations of transition metal complexes in organometallic and bioinorganic chemistry

AbstractThe field of coordination chemistry has evolved to intersect with organic chemistry and biochemistry, giving rise to the disciplines of organometallic and bioinorganic chemistry. Nuclear magnetic resonance (NMR) spectroscopy can be applied for characterizing transition metal complexes, spanning both diamagnetic and paramagnetic complexes prevalent in organometallic compounds and metalloproteins. This review offers a comprehensive overview of a wide variety of characterization techniques, ranging from basic 1H and 13C NMR spectroscopy to advanced methods such as heteronuclear experiments, polarization transfer techniques, relaxometry, and multidimensional NMR spectroscopy. The diverse array of NMR spectroscopic methods outlined here promises to enhance our comprehension of transition metal complexes, facilitating the development of innovative catalysts and therapeutics.

Nontarget Discovery of Per- and Polyfluoroalkyl Sulfonyl Halides in Soils by Integration of Derivatization and Specific Fragment-Based Liquid Chromatography-High Resolution Mass Spectrometry Screening.

Though long recognized as synthetic precursors to other poly- and perfluoroalkyl substances (PFASs), most poly- and perfluoroalkyl sulfonyl halides (PASXs) cannot be directly measured and have generally received minimal attention. Inspired by the redox reaction between sulfonyl halide groups and p-toluenethiol in organic chemistry, we developed a novel nontarget analysis strategy for PASXs by intergrating derivatization and specific fragment-based liquid chromatography-high resolution mass spectrometry screening for m/z 82.961 [SO2F-] and m/z 95.934 [S2O2-]. By using this strategy, we discovered 11 PASXs, namely, perfluoroalkyl sulfonyl fluorides (5), polyfluoroalkyl sulfonyl fluorides (2), unsaturated perfluoroalkyl sulfonyl fluoride (1), and perfluoroalkyl sulfonyl chlorides (3) in soil samples collected from an abandoned fluorochemical manufacturing park. These average ∑PASXs concentrations were 1120 μg kg-1 (range: 9.7-9860 μg kg-1), which were very likely to be the key intermediates and undesired byproducts of electrochemical fluorination processes. Spatial variation in the mass ratio of ∑PASXs to ∑PFSAs (range: 0.7-795%) also indicates their different transportation pathways. More importantly, the decline of PASXs and increase of perfluoroalkyl sulfonates (when compared to a prior study at this site) suggest the continued hydrolysis of PASXs and the relatively fast environmental transformation rates in the abandoned fluorochemical park soils. Overall, these findings demonstrated the utility of a novel nontarget analysis strategy, which may change most PASXs from inferred precursors to measured intermediates and further could be adapted for structures, distribution, and transformation studies of PFASXs in other matrices.

Personalized System of Instruction for the Foundational Knowledge of Organic Chemistry

Personalized System of Instruction for the Foundational Knowledge of Organic Chemistry

Zero-field J-spectroscopy of quadrupolar nuclei

Zero- to ultralow-field nuclear magnetic resonance (ZULF NMR) allows molecular structure elucidation via measurement of electron-mediated spin-spin J-couplings. This study examines zero-field J-spectra from molecules with quadrupolar nuclei, exemplified by solutions of various isotopologues of ammonium cations. The spectra reveal differences between various isotopologues upon extracting precise J-coupling values from pulse-acquire measurements. A primary isotope effect, △J=γ14N/γ15NJ15NH−J14NH≈−58\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ riangle J=\\left({\\gamma }_{{}^{14}{{{{{\\rm{N}}}}}}}/{\\gamma }_{{}^{15}{{{{{\\rm{N}}}}}}}\\right){J}_{{}^{15}{{{{{\\rm{N}}}}}}{{{{{\\rm{H}}}}}}}-{J}_{{}^{14}{{{{{\\rm{N}}}}}}{{{{{\\rm{H}}}}}}}\\approx -58$$\\end{document} mHz, is deduced by analysis of the proton-nitrogen J-coupling ratios. This study points toward further experiments with symmetric cations containing quadrupolar nuclei, promising applications in biomedicine, energy storage, and benchmarking quantum chemistry calculations.

Innovative cascade reaction for 2H-indazole derivative synthesis.

In the realm of synthetic organic chemistry, by using a one-pot sequential combination of MCR, it is possible to manufacture chemical commodities (fine chemicals, agrochemicals, and pharmaceutical substances) that enhance our quality of life while generating less waste materials and increasing economic advantages. With this motivation, using a "one-pot" method with multiple components, we present a relatively simple way to make stereoselective substitute 2H-indazole analogues for this study. Firstly, functionalised 3-bromo-4-((methylthio)methyl) derivatives were produced using DMSO as both a carbon source and a solvent, in conjunction with TMSOTf as the Lewis acid promoter. These derivatives were then utilised in the synthesis of 2-H-indazole derivatives with an up to 80% yield using t-Bu3PHBF4 as the ligand and Cs2CO3 as the base, in the presence of a Pd catalyst at 100°C in an airtight tube. The phenyl ring is endowed with an electron-releasing group situated at position C-6, which efficiently synthesises several 2-H-indazol derivatives with cost-efficient and noteworthy yields by using this method. A comparative analysis of a number of halogen derivatives was also undertaken, using a variety of solvents that were classified according to their halogen group. To confirm the structures of the synthesised target compounds, spectrometric analysis (1H NMR, 13C NMR, and LCMS) was performed.

Enantioselective nickel-catalyzed anodic oxidative dienylation and allylation reactions

Precision control of stereochemistry in radical reactions remains a formidable challenge due to the prevalence of incidental racemic background reactions resulting from undirected substrate oxidation in the absence of chiral induction. In this study, we devised an thoughtful approach—electricity-driven asymmetric Lewis acid catalysis—to circumvent this impediment. This methodology facilitates both asymmetric dienylation and allylation reactions, resulting in the formation of all-carbon quaternary stereocenters and demonstrating significant potential in the modular synthesis of functional and chiral benzoxazole-oxazoline (Boox) ligands. Notably, the involvement of chiral Lewis acids in both the electrochemical activation and stereoselectivity-defining radical stages offers innovative departures for designing single electron transfer-based reactions, significantly underscoring the relevance of this approach as a multifaceted and universally applicable strategy for various fields of study, including electrosynthesis, organic chemistry, and drug discovery.

Mechanistic insights into C(sp2)-H activation in 1-Phenyl-4-vinyl-1H-1,2,3-triazole derivatives: a theoretical study with palladium acetate catalyst.

The activation of C-H bonds is a fundamental process in synthetic organic chemistry, which enables their replacement by highly reactive functional groups. Coordination compounds serve as effective catalysts for this purpose, as they facilitate chemical transformations by interacting with C-H bonds. A comprehensive understanding of the mechanism of activation of this type of bond lays the foundation for the development of efficient protocols for cross-coupling reactions. We explored the activation of C(sp2)-H bonds in 1-Phenyl-4-vinyl-1H-1,2,3-triazole derivatives with CH3, OCH3, and NO2 substituents in the para position of the phenyl ring, using palladium acetate as catalyst. The studied reaction is the first step for subsequent conjugation of the triazoles with naphthoquinones in a Heck-type reaction to create a C-C bond. The basic nitrogen atoms of the 1,2,3-triazole coordinate preferentially with the cationic palladium center to form an activated species. A concerted proton transfer from the terminal vinyl carbon to one of the acetate ligands with low activation energy is the main step for the C(sp2)-H activation. This study offers significant mechanistic insights for enhancing the effectiveness of C(sp2)-H activation protocols in organic synthesis. All calculations were performed using the Gaussian 09 software package and density functional theory (DFT). The structures of all reaction path components were fully optimized using the CAM-B3LYP functional with the Def2-SVP basis set. The optimized geometries were analyzed by computing the second-order Hessian matrix to confirm that the corresponding minimum or transition state was located. To account for solvent effects, the Polarizable Continuum Model of the Integral Equation Formalism (IEFPCM) with water as the solvent was used.

The Vinyl Group: Small but Mighty ‐ Transition Metal Catalyzed and Non‐Catalyzed Vinylation Reactions

Transition metal catalysis allows for the efficient and selective introduction of vinyl moieties onto organic molecules and offers a versatile approach to synthesizing complex organic molecules. Nonetheless, few transition‐metal free vinylation reactions have also been reported, exhibiting exceptional functional group tolerance and circumventing selectivity issues. This review provides an overview of carbon, nitrogen and oxygen vinylation, presenting innovative strategies and key advancements in the field. Hence, it will serve as a valuable resource for organic chemists who are interested in the synthesis of vinyl‐containing compounds. By understanding the diverse strategies involved in vinylation, readers will gain insights into harnessing this powerful synthetic methodology for the efficient construction of carbon‐carbon and carbon‐heteroatom bonds.