Topics in Current Chemistry最新文献

DNA is commonly known as the “molecule of life” because it holds the genetic instructions for all living organisms on Earth. The utilization of modified nucleosides holds the potential to transform the management of a wide range of human illnesses. Modified nucleosides and their role directly led to the 2023 Nobel prize. Acyclic nucleosides, due to their distinctive physiochemical and biological characteristics, rank among the most adaptable modified nucleosides in the field of medicinal chemistry. Acyclic nucleosides are more resistant to chemical and biological deterioration, and their adaptable acyclic structure makes it possible for them to interact with various enzymes. A phosphonate group, which is linked via an aliphatic functionality to a purine or a pyrimidine base, distinguishes acyclic nucleoside phosphonates (ANPs) from other nucleotide analogs. Acyclic nucleosides and their derivatives have demonstrated various biological activities such as anti-viral, anti-bacterial, anti-cancer, anti-microbial, etc. Ganciclovir, Famciclovir, and Penciclovir are the acyclic nucleoside-based drugs approved by FDA for the treatment of various diseases. Thus, acyclic nucleosides are extremely useful for generating a variety of unique bioactive chemicals. Their biological activities as well as selectivity is significantly influenced by the stereochemistry of the acyclic nucleosides because chiral acyclic nucleosides have drawn a lot of interest due to their intriguing biological functions and potential as medicines. For example, tenofovir's (R) enantiomer is roughly 50 times more potent against HIV than its (S) counterpart. We can confidently state, “The most promising developments are yet to come in the realm of acyclic nucleosides!” Herein, we have covered the most current developments in the field of chemical synthesis and therapeutic applications of acyclic nucleosides based upon our continued interest and activity in this field since mid-1990’s.

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The benzoxazole is one of the most widely exploited heterocycles in drug discovery. Natural occurring and synthetic benzoxazoles show a broad range of biological activities. Many benzoxazoles are available for treating several diseases, and, to date, a few are in clinical trials. Moreover, an ever-increasing number of benzoxazole derivatives are under investigation in the early drug discovery phase and as potential hit or lead compounds. This perspective is an attempt to thoroughly review the rational design, the structure–activity relationship, and the biological activity of the most notable benzoxazoles developed during the past 5 years (period 2019–to date) in cancers, neurological disorders, and inflammation. We also briefly overviewed each target and its role in the disease. The huge amount of work examined suggests the great potential of the scaffold and the high interest of the scientific community in novel biologically active compounds containing the benzoxazole core.

The astounding reactivity of tert-butoxides in transition metal-free coupling reactions is driving the scientific community towards a new era of environmental friendly, as well as cost-effective, transformation strategies. Transition metal-catalyzed coupling reactions generate hazardous wastes and require harsh reaction conditions, mostly at elevated temperature, which increases not only costs but also environmental concerns regarding the methodology. Tert-butoxide-catalyzed/mediated coupling reactions have several advantages and potential applications. They can form carbon–carbon, carbon–heteroatom, and heteroatom–heteroatom bonds under mild reaction conditions. Mechanistic insights into these reactions include both ionic and radical pathways, with the fate of the intermediates depending on the reaction conditions and/or additives used in the reactions. Among all of the known tert-butoxides, potassium tert-butoxide has pronounced applications in transition metal-free coupling reactions as compared to other tert-butoxides, such as sodium and lithium tert-butoxides, because of the higher electropositivity of potassium compared to sodium and lithium. Moreover, potassium tert-butoxide can act as a source of base, nucleophile and single electron donors in various important transformations. In this review, we provide an extensive overview and complete compilation of transition metal-free cross-coupling reactions catalyzed/promoted by tert-butoxides during the past 10 years.

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Tert-butoxide-mediated/activated cross-coupling reactions under the transition metal-free condition for benign organic transformation using a greener approach.

In recent years, the near-infrared (NIR) light-emitting materials have attracted increasing attention due to the broad application prospects in the fields of military industry, aerospace, lighting, display and wearable devices. As the transition metal complexes, platinum(II) complexes have been shown to emit luminescence efficiently in NIR organic light-emitting diodes because of the unique d⁸ electron structure. This structure ensures that the platinum(II) complex molecules exhibit a high planarity, variety of excited states, and strong intermolecular interactions. This review summarizes the research progress of deep red to NIR organic light-emitting materials based on platinum(II) complexes in recent years and provides a certain reference for the further design and synthesis of NIR platinum(II) complex luminescent materials with superior performance.

In this article, we examine the recent uses of magnetic metal–organic frameworks (MMOFs). MMOFs can be used in various fields such as water purification, laboratory, food, environment, etc. Their materials can be composed of different metals and ligands, each of which has its own properties. Also, the presence of a magnetic property in these absorbents adds good features such as easy separation, faster absorption, and better interaction with other particles, which improves their application and performance. In recent years, various types of these compounds have been made, and, in this article, while classifying them, we will discuss the structure and application of some MMOFs.

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This review provides an in-depth examination of recent progress in the development of chemosensors, with a particular emphasis on colorimetric and fluorescent probes. It systematically explores various sensing mechanisms, including metal-to-ligand charge transfer (MLCT), ligand-to-metal charge transfer (LMCT), photoinduced electron transfer (PET), intramolecular charge transfer (ICT), and fluorescence resonance energy transfer (FRET), and elucidates the mechanism of action for cation and anion chemosensors. Special attention is given to phenothiazine-based fluorescence probes, highlighting their exceptional sensitivity and rapid detection abilities for a broad spectrum of analytes, including cations, anions, and small molecules. Phenothiazine chemosensors have emerged as versatile tools widely employed in a multitude of applications, spanning environmental and biomedical fields. Furthermore, it addresses existing challenges and offers insights into future research directions, aiming to facilitate the continued advancement of phenothiazine-based fluorescent probes.

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The enzyme-mimicking nature of versatile nanomaterials proposes a new class of materials categorized as nano-enzymes, ornanozymes. They are artificial enzymes fabricated by functionalizing nanomaterials to generate active sites that can mimic enzyme-like functions. Materials extend from metals and oxides to inorganic nanoparticles possessing intrinsic enzyme-like properties. High cost, low stability, difficulty in separation, reusability, and storage issues of natural enzymes can be well addressed by nanozymes. Since 2007, more than 100 nanozymes have been reported that mimic enzymes like peroxidase, oxidase, catalase, protease, nuclease, hydrolase, superoxide dismutase, etc. In addition, several nanozymes can also exhibit multi-enzyme properties. Vast applications have been reported by exploiting the chemical, optical, and physiochemical properties offered by nanozymes. This review focuses on the reported nanozymes fabricated from a variety of materials along with their enzyme-mimicking activity involving tuning of materials such as metal nanoparticles (NPs), metal-oxide NPs, metal–organic framework (MOF), covalent organic framework (COF), and carbon-based NPs. Furthermore, diverse applications of nanozymes in biomedical research are discussed in detail.

Supramolecular polymers are polymeric materials of monomeric fragments, held jointly by reversible and directional non-covalent interactions such as multiple hydrogen-bonding, charge transfer effects, host–guest interactions, metal coordination, and aromatic stacking. This review article on the Hamilton-based supramolecular polymers aims to shed light on the molecular recognition achievements by the Hamilton-based polymeric systems, evaluate Hamilton receptor’s future prospects, and capitalize its potential applications in supramolecular chemistry. To the best of our knowledge, this is the first elaborative and sole manuscript in which polymeric Hamilton receptors are being exposed in detail. The first portion of this manuscript is related to the importance and urgency of polymers along with the historic background of Hamilton receptors. The middle section discloses the potential applications of Hamilton-type receptors in various fields, e.g., dendrimers, mechanically polymeric rotaxanes, and self-assemblies. The final section of the manuscript discloses the future aspects and the importance of novel polymer-based Hamilton-type receptors in the modern era. We believe that this first review in this emerging yet immature field will be useful to inspire scientists around the world to find the unseen future prospects, thereby boosting the field related to this valued artificial receptor in the province of supramolecular chemistry and also in other domains of scientific fields and technology, as well.

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In this review, we present a systematic and comprehensive summary of the recent developments in the synthetic strategies of 2-(2-hydroxyarylsubstituted)-benzothiazole (HBT) framework along with incorporation of various substituents on phenolic and benzothiazole rings which affect the emission process. The literature, spanning the years 2015–2024, on excited-state intramolecular proton transfer (ESIPT)-based studies of HBT derivatives comprising the effects of solvent polarity, substituents, and extended conjugation on fluorophores has been searched. ESIPT, intramolecular charge transfer, and aggregation-induced emissions enable these fluorescent probes to specifically interact with analytes, thereby altering their luminescence characteristics to achieve analyte detection. These fluorescent probes exhibit large Stokes shifts, high quantum yields, and excellent color transitions. Finally, the applications of HBTs as ESIPT-based fluorescent probes for the detection of cations, anions, and biomolecules have been summarized. We anticipate that this review will provide a comprehensive overview of the current state of research in this field and encourage researchers to develop novel ESIPT-based fluorophores with new applications.

In the past few years, there has been notable advancement in nanotechnology, leading to the development of new materials with potential uses in the medical field, especially in cancer diagnosis, imaging, and therapy. Black phosphorus quantum dots (BPQDs) are one of the emerging nanomaterials that have generated interest due to their unique properties and potential in biomedical applications. This review aims to give a detailed overview of how BPQDs are synthesized, characterized, and utilized. The synthesis methods of BPQDs are discussed, with a focus on obtaining size-controlled and high-quality BPQDs. Two main approaches, top-down exfoliation and bottom-up techniques, are described. Despite advancements in synthesis, there are challenges hindering the practical application of BPQDs, such as poor dispersion and short durability. To address these issues, techniques to enhance biocompatibility and reduce potential toxicity, such as surface modifications, are discussed. BPQDs have potential in bioimaging as they offer higher resolution and sensitivity compared with traditional imaging agents. Their small size and expansive surface area make them suitable for drug delivery systems, enabling the effective incorporation of therapeutic substances. By functionalizing BPQDs with targeting ligands, they can selectively bind to cancer cells or tissue, making them ideal for targeted therapies. Moreover, BPQDs can serve as biosensors to detect biomarkers in bodily fluids, further expanding their biomedical applications. However, before they can be successfully translated into clinical settings, further research is needed to optimize the synthesis methods of BPQDs and evaluate their long-term safety profiles. Nonetheless, with ongoing research and development, the medical uses of BPQDs are expected to expand.

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