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N-heterocyclic carbene (NHC) organocatalysis has been developed as a powerful tool in modern synthetic chemistry. NHC catalytic activation of ynals and alkynoic acid derivatives provided versatile reactions that involve acetylenic Breslow and/or acylazolium as key intermediates, and diverse transformations have been established for access to molecules with unique skeletons in efficient fashions. Herein we summarize the recent achievements in NHC-catalyzed reactions involving acetylenic Breslow and/or acylazolium intermediates. Different reactions belonging to three catalytic modes, including (1) conjugate additions to acetylenic Breslow derived α,β-unsaturated acylazolium intermediates, (2) β-umpolung of ynals via acetylenic Breslow intermediates, and (3) conjugate additions to acetylenic acylazolium intermediates, are emphasized with examples and plausible mechanisms cited to guide a better understanding.

Organic sulfur compounds encompass a vast and diverse variety of species that possess unique biological activity due to the presence of sulfur atoms or sulfur-containing functional groups. These compounds are widely present in natural products, pharmaceuticals, agricultural chemicals, and functional materials. In recent years, numerous sulfur-containing compounds such as thiols, thioethers, disulfides, thiourea, dimethyl sulfoxide, sulfonates and their derivatives, as well as sulfur-containing inorganic compounds, have been utilized as coupling agents to synthesize (hetero)aryl sulfides via C-H Functionalization. These novel transformations provide effective methods for constructing C-S bond of (hetero)arenes, while also expanding the scope of (hetero)aryl sulfides with the potential biological activity. Therefore, the synthesis of aryl sulfides through C-H bond functionalization has attracted widespread attention. This review mainly focuses on the construction of (hetero)aryl sulfides via C-H bond functionalization since 2015. We hope this review offers a useful conceptual overview and inspires further advancements in the efficient construction of C-S bonds.

Alkylation reactions and their products are considered crucial in various contexts. Synthetically, the alkylation of a nucleophile is usually promoted using hazardous alkyl halides. Here, we aim to highlight the potential of pnictogen (ammonium or phosphonium) and chalcogen salts (sulfonium, selenonium, and telluronium) to function as alkylating agents. These compounds can be considered as non-volatile electrophilic alkyl reservoirs. We will center our discussion on the strategies developed in recent years to expand the synthetic utility of these salts in terms of transferable alkyl groups, substrate scope, and product selectivity.

This review provides a comprehensive overview of research on 1,2,4-triazoles conducted over the last fifteen years. 1,2,4-Triazoles are highly significant in the pharmaceutical industry, with numerous compounds from this class used clinically as antifungal, antiviral, antibacterial, anti-inflammatory, and antitubercular agents. Beyond their pharmaceutical relevance, this review also explores their role in material science and agriculture. In material science, 1,2,4-triazoles are gaining prominence, particularly in the development of energetic materials (EMs), due to their exceptional properties such as thermal stability, coordination ability, and performance comparable to well-known explosives. Their applications extend to polymers, corrosion inhibitors, and metal-organic frameworks (MOFs), and they play a significant role in the development of functional materials for sensors, catalysis, and energy storage. Additionally, the review addresses general aspects and synthetic methodologies for the functionalization and construction of the 1,2,4-triazole ring. Synthetic methods discussed include metalation synthesis, cyclization of hydrazine derivatives, multicomponent reactions, cyclization of amides and amidines, and microwave-assisted synthesis. Given the significance of the triazole scaffold, its synthesis has garnered considerable attention due to its wide-ranging applications across various industrial sectors.

On June 1, 1965, R. B. Woodward and Roald Hoffmann published their third communication in the Journal of the American Chemical Society in which they applied orbital symmetry control to explain the mechanism of a wide variety of valence isomerizations that they termed "sigmatropic reactions." This publication reveals the research trajectory taken by Hoffmann from which this portion of the no-mechanism problem was solved. Hoffmann used five different quantum chemical tools, all based on either extended Hückel theoretical calculations or frontier molecular orbital theory, in his research. Hoffmann's laboratory notebooks and his three draft manuscripts along with Woodward's four subsequent drafts have survived the past 59 years and provide an excellent window into the thinking and manuscript-writing processes used by these Nobel laureates in February-April 1965.

The existing and emerging demand for materials for life and health has contributed to the cultivation and development of respective markets. Nevertheless, the current generation of biomedical materials has yet to fully satisfy the clinical requirements of the market, which is still in its relative infancy. Research and development in this area must be prioritized in light of the pivotal role of new life and health materials in the biological field. Among many life and health materials, GQDs, an emerging nanomaterial, exhibit considerable promise in the biomedical field, primarily due to their exceptional properties. Furthermore, the direct preparation and functionalization of GQDs have facilitated the development of specific functional composites based on GQDs. The biological applications of GQDs are undergoing rapid growth, which makes it necessary to publish a review article presenting the latest advances in this field. This review provides an overview of the significant advances in synthesizing GQDs, the techniques employed for structural characterizations, and the properties that have been elucidated. Furthermore, it presents recent findings on applying GQDs in antimicrobial, anticancer, biosensing, drug delivery, and bioimaging applications. Finally, it explores the potential of GQDs in biomedicine and biotechnology, highlighting the current challenges that remain to be addressed.

This review provides a comprehensive examination of the applications of the seminal coupling principle introduced by Siegfried Dähne and Dieter Leupold in 1966. Their heuristic and groundbreaking work proposed that combining multiple polymethine subunits within a single chromophore enables orbital coupling, consequently narrowing the HOMO-LUMO gap, and yielding redshifted optical properties. These outcomes are particularly valuable for developing organic dyes tailored for visible-to-near-infrared applications. Despite their potential, coupled polymethines remain relatively underexplored, with most reported instances being serendipitous discoveries over the last six decades. In light of this, our review compiles and discusses the reported coupled polymethine structures, covering synthetic, spectroscopic, theoretical and applicative aspects, offering insights into the structure-property relationships of this unique class of dyes and perspectives for their future applications.

The ongoing global shift towards sustainability in electrical engineering necessitates novel materials that offer both ecological and technical benefits. Biomass-derived carbon materials (BCMs) are emerging as cornerstones in this transition due to their sustainability, cost-effectiveness, and versatile properties. This review explores the expansive role of BCMs across various electrical engineering applications, emphasizing their transformative impact and potential in fostering a sustainable technological ecosystem. The fundamentals of BCMs are investigated, including their unique structures, diverse synthesis procedures, and significant electrical and electrochemical properties. A detailed examination of recent innovations in BCM applications for energy storage, such as batteries and supercapacitors, and their pivotal role in developing advanced electronic components like sensors, detectors, and electromagnetic interference shielding composites has been covered. BCMs offer superior electrical conductivities, tunable surface chemistries, and mechanical properties compared to traditional carbon sources. These can be further enhanced through innovative doping and functionalization techniques. Moreover, this review identifies challenges related to scalability and uniformity in properties and proposes future research directions to overcome these hurdles. By integrating insights from recent studies with a forward-looking perspective, this paper sets the stage for the next generation of electrical engineering solutions powered by biomass-derived materials, aligning technological advancement with environmental stewardship.

Carbon dioxide is a major greenhouse gas and a safe, abundant, easily accessible, and renewable C1 resource that can be chemically converted into high value-added chemicals, fuels and materials. The preparation of urea, organic carbonates, salicylic acid, etc. from CO₂ through non-reduction conversion has been used in industrial production, while CO₂ reduction transformation has become a research hotspot in recent years due to its involvement in energy storage and product diversification. Designing suitable catalysts to achieve efficient and selective conversion of CO₂ is crucial due to its thermodynamic stability and kinetic inertness. From this perspective, the redistribution of charges within CO₂ molecules through the interaction of Lewis acid/base or metal complexes with CO₂, or the forced transfer of electrons to CO₂ through photo- or electrocatalysis, is a commonly used effective way to activate CO₂. Based on understanding of the activation/reaction mechanism on a molecular level, we have developed metal complexes, metal salts, inorganic/organic salts, ionic liquids, as well as nitrogen rich and porous materials as efficient catalysts for CO₂ reductive conversions. The goal of this personal account is to summarize the catalytic processes of CO₂ reductive conversion that have been developed in the past 7 years: 1) For the reductive functionalization of CO₂, the major challenge lies in accurately adjusting reaction parameters (such as pressure) to achieve high catalytic efficiency and the product selectivity; 2) For photocatalytic or electrocatalytic reduction of CO₂, how to suppress competitive hydrogen evolution reactions and improve catalyst stability are key points that requires continuous attention.

Global efforts toward establishing a circular carbon economy have guided research interests towards exploring renewable technologies that can replace environmentally harmful fossil fuel-based production routes. In this context, sugar-based bio-derived substrates have been identified as renewable molecules for future implementation in chemical industries. Tartaric acid, a special C₄ bio-compound with two hydroxyl and carboxylic groups in the structure, displays great potential for the food, polymer, and pharmaceutical industries due to its unique biological reactivity and performance-enhancing properties. To this point, there has yet to be a comprehensive literature review and perspective on the applications and synthesis of tartaric acid. As such, we have conducted a detailed and thorough outlook and discussion in terms of biological activity, organic synthesis, catalysis, structural characterization and synthetic routes. Lastly, we provide a critical discussion on the applications and synthesis of tartaric acid to give our insights into developing sustainable chemical technologies for the future.