You're using an outdated browser. Please upgrade to a modern browser for the best experience.
Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort by:
Most Viewed Latest Alphabetical (A-Z) Alphabetical (Z-A)
Filter:
All Topic Review Biography Peer Reviewed Entry Video Entry
Topic Review
Structures of Biphenarenes
In 2015, Li and co-workers synthesized a new macrocyclic host named biphenarenes, which including basic biphen[n]arenes, functional biphen[n]arenes, and cage compounds. Typically, biphenarenes are made up of 4,4′-biphenol or 4,4′-biphenol ether units linked by methylene bridges at the 3- and 3′-positions. The synthesis of biphenarenes is based on the linking of reaction modules to form macrocycles by Friedel–Crafts alkylation. In addition, modular synthetic strategy is a versatile method for the synthesis of biphenarenes, which can increase the cavity sizes by changing the structural units. For example, the cavity sizes of biphenarenes can be easily increased using long and rigid structural units or increasing the number of structural units. Meanwhile, gram-scale synthesis of biphenarenes is easily achieved in a laboratory. The purification of biphenarenes can be achieved by column chromatography and recrystallization. Furthermore, biphenarenes are easy to prepare since they can be obtained by a one-step condensation reaction using commercial reagents. Biphenarenes show good performance in adsorptive separation, sensing and drug delivery, and have broad application prospects in chemistry, biology, materials science and other fields.
  • 701
  • 13 Jun 2023
Topic Review
ApDOS (Aminocatalytic Privileged Diversity-Oriented Synthesis)
ApDOS (Aminocatalytic privileged Diversity-Oriented Synthesis) is a synthetic strategy that integrates the principles of aminocatalysis and diversity-oriented synthesis (DOS) to access structurally diverse libraries of privileged molecular scaffolds. Privileged structures—defined as frameworks capable of high-affinity binding to multiple biological targets—are key motifs in medicinal chemistry and chemical biology. ApDOS utilizes various aminocatalytic activation modes, including enamine, iminium ion, dienamine, trienamine, tetraenamine, and vinylogous iminium ion catalysis, to transform simple and readily available building blocks such as aldehydes and ketones into stereochemically rich and functionally elaborate architectures. The conceptual framework of ApDOS builds on the modularity and reactivity of aminocatalytic intermediates to populate biologically relevant regions of chemical space. By enabling mono- and multicomponent reactions—including cascade and domino sequences—ApDOS expands the synthetic utility of aminocatalysis beyond conventional target-oriented strategies. This methodology has proven particularly effective for the construction of spirocyclic, fused, bridged, and polycyclic scaffolds, often in a highly enantioselective and atom-economical manner. ApDOS represents a general platform for exploring molecular diversity via catalytic reactivity modes and offers significant potential for drug discovery and chemical probe development.
  • 697
  • 09 Apr 2025
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.
  • 691
  • 14 Mar 2024
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.
  • 686
  • 27 Jun 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.
  • 671
  • 01 Mar 2024
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.
  • 668
  • 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.
  • 658
  • 09 Feb 2023
Topic Review
Organic Fouling Influencing Factors in Membrane Separation Processes
Organic matter such as raw wastewater organic matter (WOM), effluent organic matter (EOM), and natural organic matter (NOM) can contribute to membrane fouling in membrane separation processes. These organic compounds can include proteins, lipids, amino acids, polysaccharides, colloidal particles, humic and folic acids, and other complex organic molecules. These compounds can accumulate on the membrane surface or inside pores, leading to fouling. The accumulation of organic matter on the membrane surface can also lead to the formation of a biofilm, which can further exacerbate fouling and reduce the efficiency of the membrane separation process.
  • 633
  • 20 Sep 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.
  • 628
  • 25 May 2023
Topic Review
Self-Assembled Monolayer-Based Hole-Transporting Materials
Ever since self-assembled monolayers (SAMs) were adopted as hole-transporting layers (HTL) for perovskite solar cells (PSCs), numerous SAMs for HTL have been synthesized and reported. SAMs offer several unique advantages including relatively simple synthesis, straightforward molecular engineering, effective surface modification using small amounts of molecules, and suitability for large-area device fabrication. 
  • 614
  • 19 Jan 2024
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. 
  • 611
  • 29 Jan 2023
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. 
  • 611
  • 19 Oct 2023
Topic Review
Chemistry of Hypecoum Alkaloids
Genus Hypecoum Tourn. ex L. belongs to the poppy family Papaveraceae and comprises about 19 species occurring in Europe, Northern Africa and Asia. Hypecoum species have been widely used in traditional medicine as antipyretic, analgesic and anti-inflammatory remedies. The effects are associated with the biologically and pharmacologically active isoquinoline alkaloids in them such as protopines, protoberberines, benzophenanthridines, aporphines, simple isoquinolines, secoberbines, spirobenzylisoquinolines and others. 
  • 587
  • 09 Oct 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.
  • 574
  • 22 Sep 2023
Topic Review
Cobalt in the Formation of Fischer–Tropsch Synthesis Products
Hydrocarbons obtained through Fischer–Tropsch synthesis (FTS) from a mixture of CO and H2, also known as synthesis gas, are one of the promising sources of hydrocarbon feedstocks for further use in chemical and petrochemical industries. The composition of hydrocarbon mixtures depends on both the catalyst properties and the process parameters. 
  • 571
  • 24 Jul 2023
Topic Review
Chlorophyll and TiO2
Chlorophyll sensitization can improve the performance of semiconductors like TiO2 in photocatalytic reactions and light-harvesting technologies, such as solar cells. Faced with the search for renewable energy sources and sustainable technologies, the application of this natural pigment has been gaining prominence.
  • 564
  • 11 Dec 2023
Topic Review
Novel Materials for Semi-Transparent Organic Solar Cells
The rapid development of photovoltaic technology has driven the search for novel materials that can improve the cost-effectiveness and efficiency of solar cells. Organic semiconductors offer unique optical tunability and transparency, allowing customization for the absorption of specific optical spectra like near-infrared radiation. Through the molecular engineering of electron donors and acceptors, these materials can be optimized for targeted optical selectivity. This adaptability enables the development of efficient energy-harvesting devices tailored for specific spectral regions. Consequently, organic semiconductors present a promising avenue for specialized applications such as semi-transparent organic solar cells. 
  • 543
  • 23 Jan 2024
Topic Review
Stereoselective Catalytic Synthesis of Bioactive Compounds in NADESs
Deep eutectic solvents (DESs) are a mixture of two or more components, and at a particular composition, they become liquids at room temperature. When the compounds that constitute the DESs are primary metabolites namely, amino acids, organic acids, sugars, or choline derivatives, the DESs are called natural deep eutectic solvents (NADESs).
  • 502
  • 28 Feb 2024
Topic Review
Synthesis of Arylcyanomethylenequinone Oximes
Quinone methides are a class of biologically active compounds that can be used in medicine as antibacterial, antifungal, antiviral, antioxidant, and anti-inflammatory agents. In addition, quinone methides have the potential to be used as pesticides, dyes, and additives for rubber and plastics.
  • 500
  • 17 Oct 2023
Topic Review
Membrane-Active Topoisomeric Peptides
Bioactive peptides have been gaining recognition in various biomedical areas, such as intracellular drug delivery (cell-penetrating peptides, CPPs) or anti-infective action (antimicrobial peptides, AMPs), closely associated to their distinct mode of interaction with biological membranes. However, ordinary peptides formed by L-amino acids are easily decomposed by proteases in biological fluids. One way to sidestep this limitation is to use topoisomers, namely versions of the peptide made up of D-amino acids in either canonic (enantio) or inverted (retroenantio) sequence.
  • 489
  • 30 Oct 2023
  • Page
  • of
  • 16
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of COVID-19
Encyclopedia of Engineering
Encyclopedia of Social Sciences
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Academic Video Service
Feedback