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Topic Review
Acyclic Unsaturated 2π-Electron Components
Azomethine ylides are nitrogen-based three-atom components commonly used in [3+2]-cycloaddition reactions with various unsaturated 2π-electron components. These reactions are highly regio- and stereoselective and have attracted the attention of organic chemists with respect to the construction of diverse heterocycles potentially bearing four new contiguous stereogenic centers. 
  • 410
  • 29 Jan 2023
Topic Review
Heterogeneous Catalysts in the Reductive Amination of Alcohols
The synthesis of primary amines via the reductive amination of alcohols involves a hydrogen-borrowing or hydrogen-transfer mechanism, which consists of three main steps: alcohol hydroxyl dehydrogenation, carbonyl imidization, and imine hydrogenation. Heterogeneous catalysts are widely used for this reaction because of their high performance and amenability to separation and reuse.
  • 410
  • 18 Oct 2023
Topic Review
Mechanism of Organic Photovoltaics
The power conversion efficiencies (PCEs) of organic photovoltaics (OPVs) have reached more than 19%, along with the prosperous development of materials and device engineering. 
  • 409
  • 15 Jun 2023
Topic Review
Donor–Acceptor Covalent Organic Frameworks for Photocatalytic Hydrogen Production
The depletion of traditional fossil energy and the resulting environmental pollution forces people to explore new energy sources. Direct use of solar energy is now a viable solution for solving these problems. Covalent organic frameworks (COFs) are a porous crystalline material; their well-defined two-dimensional or three-dimensional frameworks can ensure the orderly arrangement of photoelectric active units, giving them potential photoelectric conversion applications. The tunable structural features endow COFs many advantages in photocatalytic hydrogen production under visible light.
  • 403
  • 16 Feb 2023
Topic Review
Application of [2.2]Paracyclophane Skeleton in Modifying Dyes
The [2.2]paracyclophane (PCP) ring has attracted extensive attention due to its features of providing not only chirality and electron-donating ability but also steric hindrance, which reduces intermolecular π–π stacking interactions and thereby improves the fluorescence properties of dyes.
  • 394
  • 14 Apr 2023
Topic Review
Glycopolymers Targeting Viruses
Diseases induced by bacterial and viral infections are common occurrences in our daily life, and the main prevention and treatment strategies are vaccination and taking antibacterial/antiviral drugs. Vaccines can only be used for specific viral infections, and the abuse of antibacterial/antiviral drugs will create multi−drug−resistant bacteria and viruses. Therefore, it is necessary to develop more targeted prevention and treatment methods against bacteria and viruses. Proteins on the surface of bacteria and viruses can specifically bind to sugar, so glycopolymers can be used as potential antibacterial and antiviral drugs.
  • 393
  • 09 Feb 2023
Topic Review
Two-Photon Absorbing Dendrimers
Dendrimers, arborescent macromolecules exhibiting a large number of functional groups at their surface, appeared as naturally attractive targets to consider as TPA chromophores. Indeed, dendrimers are a special kind of perfectly defined hyperbranched polymers constructed stepwise from a multifunctional core at the periphery of which can be grafted a large density and variety of chromophores.
  • 390
  • 14 Mar 2024
Topic Review
Amidoalkyl Naphthols: Bioactive Substances and Building Blocks
1-amidoalkyl-2-naphthol derivatives are of increasing interest due to their biological activities and further use in the preparation of other important bioactive molecules, such as aminoalkyl naphthols and oxazines.
  • 379
  • 16 Jun 2023
Topic Review
Catalytic Carbonylative Double Cyclization Reactions
Some examples of carbonylative double cyclization processes, which allow the one-step synthesis of complex molecular architectures from simple building blocks using the simplest and readily available C-1 unit (CO), are illustrated and discussed.
  • 378
  • 07 Jul 2023
Topic Review
Photodynamic Therapy against Cancer
Photodynamic therapy (PDT) is based on the initial absorption of light by the photosensitizer (PS) and the subsequent direct and oxygen-mediated reactions with the cell membrane and cytoplasmic cell components.
  • 364
  • 22 Sep 2023
Topic Review
Mechanism of Removal of Heavy Metals by NF
Nanofiltration is a type of membrane filtration that employs a semi-permeable membrane. Unlike other types of membrane filtration systems, nanofiltration membranes have pore sizes of less than 10 nm.
  • 363
  • 21 Sep 2023
Topic Review
Dual H-Bonding and Enamine Activation
Asymmetric enamine base activation of carbonyl compounds is a well-known and widely used strategy for providing functionalization of organic compounds in an efficient way. The use of solely organic substances, which in most cases are commercially available primary or secondary amines that are easy to obtain, avoids the use of hazardous substances or metal traces, making this type of catalysis a highly convenient methodology from a sustainable point of view.
  • 362
  • 27 Jul 2023
Topic Review
Organic Semiconducting Nanoparticles for Biosensor
Highly bio-compatible organic semiconductors are widely used as biosensors, but their long-term stability can be compromised due to photo-degradation and structural instability. To address this issue, scientists have developed organic semiconductor nanoparticles (OSNs) by incorporating organic semiconductors into a stable framework or self-assembled structure. OSNs have shown excellent performance and can be used as high-resolution biosensors in modern medical and biological research. They have been used for a wide range of applications, such as detecting small biological molecules, nucleic acids, and enzyme levels, as well as vascular imaging, tumor localization, and more. In particular, OSNs can simulate fine particulate matters (PM2.5, indicating particulate matter with an aerodynamic diameter less than or equal to 2.5 μm) and can be used to study the biodistribution, clearance pathways, and health effects of such particles.
  • 356
  • 25 May 2023
Topic Review
Naphthoquinones and Parkinson’s Disease
Parkinson’s disease (PD) is a pathology of neurological origin, degenerative of the region present in the central nervous system known as substantia nigra. Naphthoquinones are the most common type of quinones and compose an important series of natural distribution metabolites of plants, animals, fungi and bacteria.
  • 352
  • 17 Nov 2023
Topic Review
Organocatalytic Cycloaddition and Cyclization Reactions
Atropisomeric molecules are present in many natural products, biologically active compounds, chiral ligands and catalysts. Many elegant methodologies have been developed to access axially chiral molecules. Among them, organocatalytic cycloaddition and cyclization have attracted much attention because they have been widely used in the asymmetric synthesis of biaryl/heterobiaryls atropisomers via construction of carbo- and hetero-cycles. This strategy has undoubtedly become and will continue to be a hot topic in the field of asymmetric synthesis and catalysis.
  • 348
  • 27 Jun 2023
Topic Review
Photonic Upconversion Materials for Organic Lanthanide Complexes
Organic lanthanide complexes have garnered significant attention in various fields due to their intriguing energy transfer mechanism, enabling the upconversion (UC) of two or more low-energy photons into high-energy photons. In comparison to lanthanide-doped inorganic nanoparticles, organic UC complexes hold great promise for biological delivery applications due to their advantageous properties of controllable size and composition.
  • 346
  • 31 Aug 2023
Topic Review
Preparation of Carbon Nitride-Based S-scheme Photocatalyst
Energy shortages are a major challenge to the sustainable development of human society, and photocatalytic solar energy conversion is a potential way to alleviate energy problems. As a two-dimensional organic polymer semiconductor, carbon nitride is considered to be the most promising photocatalyst due to its stable properties, low cost, and suitable band structure. The development of carbon nitride-based S-scheme photocatalysts has been flourished, which has raised the wave of interests and reached a crescendo in the field of energy catalysis. Therefore, a timely overview on the recent progress of carbon nitride-based S-scheme heterojunctions is highly desirable, not only to unveil the basic working mechanism, but also to inspire future research directions in carbon nitride-based heterojunctions.
  • 338
  • 29 Jun 2023
Topic Review
Synthesis of S-α-(Acyloxy)alkyl Xanthates
α-(Acyloxy)alkyl radicals of general structure 1 are key intermediates in the polymerization of vinyl esters 2, especially vinyl acetate (2, R = Me); however, their use in the synthesis of small molecules has remained underdeveloped.
  • 324
  • 01 Dec 2023
Topic Review
Natural and Synthetic Antifouling Flavonoids
Marine biofouling is a major concern for the maritime industry, environment, and human health. Considering that biocides currently used in marine coatings to prevent this phenomenon are toxic to the marine environment, the search for antifoulants with environmentally safe properties is needed. Some natural and synthetic flavonoids have been evaluated over the last few years for their potential to prevent the settlement and/or the growth of marine organisms on submerged structures, thereby preventing marine biofouling.
  • 318
  • 01 Mar 2024
Topic Review
Adaptive Self-Organizing Map Using Optimal Control
The self-organizing map (SOM), which is a type of artificial neural network (ANN), was formulated as an optimal control problem. Its objective function is to minimize the mean quantization error, and the state equation is the weight updating equation of SOM. Based on the objective function and the state equations, the Hamiltonian equation based on Pontryagin’s minimum principle (PMP) was formed. 
  • 295
  • 19 Oct 2023
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