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Molecules (Basel, Switzerland) Apr 2020The reaction between organic azides and alkyne derivatives via the Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) is an efficient strategy to combine phthalocyanines... (Review)
Review
The reaction between organic azides and alkyne derivatives via the Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) is an efficient strategy to combine phthalocyanines and analogues with different materials. As examples of such materials, it can be considered the following ones: graphene oxide, carbon nanotubes, silica nanoparticles, gold nanoparticles, and quantum dots. This approach is also being relevant to conjugate phthalocyanines with carbohydrates and to obtain new sophisticated molecules; in such way, new systems with significant potential applications become available. This review highlights recent developments on the synthesis of phthalocyanine, subphthalocyanine, and porphyrazine derivatives where CuAAC reactions are the key synthetic step.
Topics: Azides; Catalysis; Chemistry Techniques, Synthetic; Click Chemistry; Electrodes; Indoles; Isoindoles; Molecular Structure; Polymers
PubMed: 32290240
DOI: 10.3390/molecules25071745 -
Molecules (Basel, Switzerland) Dec 2018We have recently discovered that the photodynamic action of many different photosensitizers (PSs) can be dramatically potentiated by addition of a solution containing a... (Review)
Review
We have recently discovered that the photodynamic action of many different photosensitizers (PSs) can be dramatically potentiated by addition of a solution containing a range of different inorganic salts. Most of these studies have centered around antimicrobial photodynamic inactivation that kills Gram-negative and Gram-positive bacteria in suspension. Addition of non-toxic water-soluble salts during illumination can kill up to six additional logs of bacterial cells (one million-fold improvement). The PSs investigated range from those that undergo mainly Type I photochemical mechanisms (electron transfer to produce superoxide, hydrogen peroxide, and hydroxyl radicals), such as phenothiazinium dyes, fullerenes, and titanium dioxide, to those that are mainly Type II (energy transfer to produce singlet oxygen), such as porphyrins, and Rose Bengal. At one extreme of the salts is sodium azide, that quenches singlet oxygen but can produce azide radicals (presumed to be highly reactive) via electron transfer from photoexcited phenothiazinium dyes. Potassium iodide is oxidized to molecular iodine by both Type I and Type II PSs, but may also form reactive iodine species. Potassium bromide is oxidized to hypobromite, but only by titanium dioxide photocatalysis (Type I). Potassium thiocyanate appears to require a mixture of Type I and Type II photochemistry to first produce sulfite, that can then form the sulfur trioxide radical anion. Potassium selenocyanate can react with either Type I or Type II (or indeed with other oxidizing agents) to produce the semi-stable selenocyanogen (SCN)₂. Finally, sodium nitrite may react with either Type I or Type II PSs to produce peroxynitrate (again, semi-stable) that can kill bacteria and nitrate tyrosine. Many of these salts (except azide) are non-toxic, and may be clinically applicable.
Topics: Anti-Infective Agents; Azides; Bromides; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Iodides; Microbial Sensitivity Tests; Nitrites; Photochemotherapy; Photosensitizing Agents; Salts; Thiocyanates; Titanium
PubMed: 30514001
DOI: 10.3390/molecules23123190 -
Molecules (Basel, Switzerland) Aug 2013The alkyne-azide cycloaddition, popularly known as the "click" reaction, has been extensively exploited in molecule/macromolecule build-up, and has offered tremendous... (Review)
Review
The alkyne-azide cycloaddition, popularly known as the "click" reaction, has been extensively exploited in molecule/macromolecule build-up, and has offered tremendous potential in the design of nanomaterials for applications in a diverse range of disciplines, including biology. Some advantageous characteristics of this coupling include high efficiency, and adaptability to the environment in which the desired covalent linking of the alkyne and azide terminated moieties needs to be carried out. The efficient delivery of active pharmaceutical agents to specific organelles, employing nanocarriers developed through the use of "click" chemistry, constitutes a continuing topical area of research. In this review, we highlight important contributions click chemistry has made in the design of macromolecule-based nanomaterials for therapeutic intervention in mitochondria and lipid droplets.
Topics: Alkynes; Azides; Click Chemistry; Mitochondria; Molecular Structure; Nanoparticles
PubMed: 23966076
DOI: 10.3390/molecules18089531 -
International Journal of Molecular... Dec 2021This review accounts for the most recent and significant research results from the literature on the design and synthesis of 1,2,3-triazole compounds and their... (Review)
Review
This review accounts for the most recent and significant research results from the literature on the design and synthesis of 1,2,3-triazole compounds and their usefulness as molecular well-defined corrosion inhibitors for steels, copper, iron, aluminum, and their alloys in several aggressive media. Of particular interest are the 1,4-disubstituted 1,2,3-triazole derivatives prepared in a regioselective manner under copper-catalyzed azide-alkyne cycloaddition (CuAAC) click reactions. They are easily and straightforwardly prepared compounds, non-toxic, environmentally friendly, and stable products to the hydrolysis under acidic conditions. Moreover, they have shown a good efficiency as corrosion inhibitors for metals and their alloys in different acidic media. The inhibition efficiencies (IEs) are evaluated from electrochemical impedance spectroscopy (EIS) parameters with different concentrations and environmental conditions. Mechanistic aspects of the 1,2,3-triazoles mediated corrosion inhibition in metals and metal alloy materials are also overviewed.
Topics: Azides; Catalysis; Click Chemistry; Corrosion; Cycloaddition Reaction; Metals; Molecular Structure; Surface Properties; Triazoles
PubMed: 35008481
DOI: 10.3390/ijms23010016 -
Organic Letters Jun 2021Azoheteroarenes make up an emerging class of photoswitchable compounds with unique photophysical properties and advantages over traditional azobenzenes. Therefore,...
Azoheteroarenes make up an emerging class of photoswitchable compounds with unique photophysical properties and advantages over traditional azobenzenes. Therefore, methods for synthesizing azoheteroarenes are highly desirable. Here, we utilize azide-alkyne click chemistry to access arylazo-1,2,3-triazoles, a previously unexplored class of azoheteroarenes that exhibit high thermal stabilities and near-quantitative bidirectional photoconversion. Controlling the catalyst or 1,3-dipole grants access to both regioisomeric arylazotriazoles and arylazoisoxazoles, highlighting the versatility of our approach.
Topics: Alkynes; Azides; Azo Compounds; Catalysis; Click Chemistry; Molecular Structure; Triazoles
PubMed: 34019429
DOI: 10.1021/acs.orglett.1c01230 -
Scientific Reports Jul 2021Sodium azide is an old poison with toxicity comparable to potassium cyanide. It would seem to be completely forgotten however, between 2000 and 2020, the number of...
Sodium azide is an old poison with toxicity comparable to potassium cyanide. It would seem to be completely forgotten however, between 2000 and 2020, the number of intentional ingestions and murders committed with sodium azide significantly increased. Furthermore, due to its extreme instability, sodium azide is difficult to detect, which poses an additional risk when used to commit a crime. In this study, the epidemiology of sodium azide exposures between 1920 and 2020 was investigated. For the determination the azide concentration in biological samples, a simple, precise and selective headspace gas chromatography method (HS-GC-FID/FID) was developed and fully validated. The limit of quantification was 0.65 µg/mL; and the limit of detection was 0.35 µg/mL; precision and accuracy did not exceed 20%. The stability study was conducted for various biological fluids (urine, bile, blood, gastric content) for 91 days in the refrigerator (4 °C) and the method for stabilization of azide was presented. The addition of a mixture of borax and sodium fluoride (w/w 3:1) to the test tubes can stabilize this poison. The described unique technique of collecting the biological samples poses a great potential for azide detection in clinical and toxicology laboratories even long time after human exposure to this substance.
Topics: Azides; Chromatography, Gas; Sodium Azide
PubMed: 34330976
DOI: 10.1038/s41598-021-95104-5 -
Cell Chemical Biology Jun 2022The site-specific incorporation of nonstandard amino acids (nsAAs) during translation has expanded the chemistry and function of proteins. The nsAA...
The site-specific incorporation of nonstandard amino acids (nsAAs) during translation has expanded the chemistry and function of proteins. The nsAA para-azido-phenylalanine (pAzF) encodes a biorthogonal chemical moiety that facilitates "click" reactions to attach diverse chemical groups for protein functionalization. However, the azide moiety is unstable in physiological conditions and is reduced to para-amino-phenylalanine (pAF). Azide reduction decreases the yield of pAzF residues in proteins to 50%-60% per azide and limits protein functionalization by click reactions. Here, we describe the use of a pH-tunable diazotransfer reaction that converts pAF to pAzF at >95% efficiency in proteins. The method selectively restores pAzF at multiple sites per protein without introducing off-target modifications. This work addresses a key limitation in the production of pAzF-containing proteins by restoring azides for multi-site functionalization with diverse chemical moieties, setting the stage for the production of genetically encoded biomaterials with broad applications in biotherapeutics, materials science, and biotechnology.
Topics: Amino Acids; Azides; Biocompatible Materials; Click Chemistry; Phenylalanine; Proteins
PubMed: 34965380
DOI: 10.1016/j.chembiol.2021.12.002 -
International Journal of Molecular... Feb 2022The copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction is considered to be the most representative ligation process within the context of the "click... (Review)
Review
The copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction is considered to be the most representative ligation process within the context of the "click chemistry" concept. This CuAAC reaction, which yields compounds containing a 1,2,3-triazole core, has become relevant in the construction of biologically complex systems, bioconjugation strategies, and supramolecular and material sciences. Although many CuAAC reactions are performed under homogenous conditions, heterogenous copper-based catalytic systems are gaining exponential interest, relying on the easy removal, recovery, and reusability of catalytically copper species. The present review covers the most recently developed copper-containing heterogenous solid catalytic systems that use solid inorganic/organic hybrid supports, and which have been used in promoting CuAAC reactions. Due to the demand for 1,2,3-triazoles as non-classical bioisosteres and as framework-based drugs, the CuAAC reaction promoted by solid heterogenous catalysts has greatly improved the recovery and removal of copper species, usually by simple filtration. In so doing, the solving of the toxicity issue regarding copper particles in compounds of biological interest has been achieved. This protocol is also expected to produce a practical chemical process for accessing such compounds on an industrial scale.
Topics: Alkynes; Azides; Catalysis; Click Chemistry; Copper; Cycloaddition Reaction; Triazoles
PubMed: 35216495
DOI: 10.3390/ijms23042383 -
Molecules (Basel, Switzerland) Dec 2022The present review narrates several reports which deal with the synthesis of fused 1,2,3-triazole containing scaffolds following a sequential multicomponent reaction... (Review)
Review
The present review narrates several reports which deal with the synthesis of fused 1,2,3-triazole containing scaffolds following a sequential multicomponent reaction (MCR)-intramolecular azide-alkyne cycloaddition (IAAC) approach. The reviewed reactions were cleverly designed so as to incorporate azide and alkyne functionalities in the MCR product which was then subjected to IAAC. The review is divided into two sections based on the number of components in the multicomponent reaction. We have aimed at a critical discussion and also have highlighted either advantages or disadvantages of each methodology.
Topics: Cycloaddition Reaction; Azides; Alkynes; Triazoles; Catalysis; Molecular Structure
PubMed: 36615500
DOI: 10.3390/molecules28010308 -
Chemical Society Reviews Apr 2010The advent of click chemistry has led to an influx of new ideas in the nucleic acids field. The copper catalysed alkyne-azide cycloaddition (CuAAC) reaction is the... (Review)
Review
The advent of click chemistry has led to an influx of new ideas in the nucleic acids field. The copper catalysed alkyne-azide cycloaddition (CuAAC) reaction is the method of choice for DNA click chemistry due to its remarkable efficiency. It has been used to label oligonucleotides with fluorescent dyes, sugars, peptides and other reporter groups, to cyclise DNA, to synthesise DNA catenanes, to join oligonucleotides to PNA, and to produce analogues of DNA with modified nucleobases and backbones. In this critical review we describe some of the pioneering work that has been carried out in this area (78 references).
Topics: Alkynes; Azides; Catalysis; Copper; Cyclization; DNA; Oligonucleotides; Peptide Nucleic Acids
PubMed: 20309492
DOI: 10.1039/b901971p