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Chemistry (Weinheim An Der Bergstrasse,... Oct 2017Reduction of phosphine oxides to the corresponding phosphines represents the most straightforward method to prepare these valuable reagents. However, existing methods to...
Reduction of phosphine oxides to the corresponding phosphines represents the most straightforward method to prepare these valuable reagents. However, existing methods to reduce phosphine oxides suffer from inadequate chemoselectivity due to the strength of the P=O bond and/or poor atom economy. Herein, we report the discovery of the most powerful chemoselective reductant for this transformation to date, 1,3-diphenyl-disiloxane (DPDS). Additive-free DPDS selectively reduces both secondary and tertiary phosphine oxides with retention of configuration even in the presence of aldehyde, nitro, ester, α,β-unsaturated carbonyls, azocarboxylates, and cyano functional groups. Arrhenius analysis indicates that the activation barrier for reduction by DPDS is significantly lower than any previously calculated silane reduction system. Inclusion of a catalytic Brønsted acid further reduced the activation barrier and led to the first silane-mediated reduction of acyclic phosphine oxides at room temperature.
PubMed: 28840623
DOI: 10.1002/chem.201703875 -
Molecules (Basel, Switzerland) Oct 2015Aromatic polyazides are widely used as starting materials in organic synthesis and photochemical studies, as well as photoresists in microelectronics and as... (Review)
Review
Aromatic polyazides are widely used as starting materials in organic synthesis and photochemical studies, as well as photoresists in microelectronics and as cross-linking agents in polymer chemistry. Some aromatic polyazides possess high antitumor activity, while many others are of considerable interest as high-energy materials and precursors of high-spin nitrenes and C₃N₄ carbon nitride nanomaterials. The use of aromatic polyazides in click-reactions may be a new promising direction in the design of various supramolecular systems possessing interesting chemical, physical and biological properties. This review is devoted to the synthesis, properties and applications of six-membered aromatic compounds containing three and more azido groups in the ring.
Topics: Azides; Click Chemistry; Heterocyclic Compounds; Nitriles; Phosphines; Photolysis
PubMed: 26506330
DOI: 10.3390/molecules201019142 -
Molecules (Basel, Switzerland) Jan 2021Dendrimers are hyperbranched macromolecules, which are synthesized step-by-step by the repetition of a series of reactions. While many different types of dendrimers are... (Review)
Review
Dendrimers are hyperbranched macromolecules, which are synthesized step-by-step by the repetition of a series of reactions. While many different types of dendrimers are known, this review focusses on the use of trivalent phosphorus derivatives (essentially phosphines and phosphoramidites) for the synthesis of dendrimers. The first part presents dendrimers constituted of phosphines at each branching point. The other parts display the use of trivalent phosphorus derivatives during the synthesis of dendrimers. Different types of reactions have been applied to phosphines. The very first examples of phosphorus-containing dendrimers were obtained by the alkylation of phosphines. Then, several families of dendrimers were elaborated by reaction of phosphoramidites. Such a type of reaction is the base of the solid phase synthesis of oligonucleotides; it has been applied in particular for the synthesis of dendrimers constituted of oligonucleotides. Finally, the Staudinger reaction between phosphines and azides afforded different families of dendrimers, and was at the origin of accelerated methods of synthesis of dendrimers. Besides, the reactivity of the P=N-P=S linkages created by this reaction led to very original dendritic structures.
Topics: Alkylation; Chemistry Techniques, Synthetic; Dendrimers; Molecular Structure; Organophosphorus Compounds; Phosphines; Phosphorus
PubMed: 33430439
DOI: 10.3390/molecules26020269 -
The Indian Journal of Medical Research Oct 2016Phosphides used as an insecticide and rodenticide, produce phosphine (PH3) which causes accidental and intentional poisoning cases and deaths. There is no specific...
BACKGROUND & OBJECTIVES
Phosphides used as an insecticide and rodenticide, produce phosphine (PH3) which causes accidental and intentional poisoning cases and deaths. There is no specific treatment or antidote available for PH3poisoning. It is suggested that PH3-induced toxicity is associated with adenosine triphosphate (ATP) depletion; therefore, in this study the effect of some nutrients was evaluated on PH3cytotoxicity in a cell culture model.
METHODS
PH3was generated from reaction of zinc phosphide (10 mM) with water in the closed culture medium of HepG2 cells, and cytotoxicity was measured after one and three hours of incubation. ATP, glutathione (GSH) and lipid peroxidation were also assessed at one or three hours post-incubation. ATP suppliers including dihydroxyacetone, glyceraldehyde and fructose were added to the culture medium 10 min before PH3generation to prevent or reduce phosphine-induced cytotoxicity.
RESULTS
Phosphine caused about 30 and 66 per cent cell death at one and three hours of incubation, respectively. ATP content of the cells was depleted to 14.7 per cent of control at one hour of incubation. ATP suppliers were able to prevent cytotoxicity and ATP depletion induced by PH3. Dihydroxyacetone, α-ketoglutarate, fructose and mannitol restored the ATP content of the cells from 14.7 per cent to about 40 , 34 , 32 and 30 per cent, respectively. Lipid peroxidation and GSH depletion were not significantly induced by zinc phosphide in this study.
INTERPRETATION & CONCLUSIONS
The results supported the hypothesis that phosphine-induced cytotoxicity was due to decrease of ATP levels. ATP suppliers could prevent its toxicity by generating ATP through glycolysis. α-keto compounds such as dihydroxyacetone and α-ketoglutarate may bind to phosphine and restore mitochondrial respiration.
Topics: Adenosine Triphosphate; Cell Death; Cell Survival; Dihydroxyacetone; Fructose; Glutathione; Hep G2 Cells; Humans; Ketoglutaric Acids; Lipid Peroxidation; Liver; Mannitol; Mitochondria; Phosphines
PubMed: 28256464
DOI: 10.4103/0971-5916.200896 -
The Journal of Organic Chemistry May 2023The fragrance compound indomuscone is used here as a scaffold to prepare two different sterically hindered phosphines, one aromatic and another alkylic, in good yields,...
The fragrance compound indomuscone is used here as a scaffold to prepare two different sterically hindered phosphines, one aromatic and another alkylic, in good yields, after four synthetic steps. The new phosphines show enhanced electronic and steric properties when compared to benchmark commercial phosphine ligands, which is reflected in the catalytic results obtained for representative palladium-catalyzed reactions such as the telomerization reaction, the Buchwald-Hartwig and Suzuki cross-coupling reactions of chloroaromatic rings, and the semi-hydrogenation reaction of an alkyne. In particular, the indomuscone-based aromatic phosphine ligand leads to the highest selectivity for the tail-to-head telomerization product between isoprene and methanol, while the indomuscone-based alkylic phosphine ligand shows extraordinary similarities with the Buchwald-type SPhos phosphine ligand.
PubMed: 37026761
DOI: 10.1021/acs.joc.3c00314 -
Inorganic Chemistry May 2021Low-toxic InP quantum dots (QDs) as an ideal candidate for Cd-based QDs have tremendous potential for next-generation commercial display and biological detection...
Low-toxic InP quantum dots (QDs) as an ideal candidate for Cd-based QDs have tremendous potential for next-generation commercial display and biological detection applications. However, the progress in biological detection is still far behind that of the Cd-based QDs. This is mainly because the InP-based QDs are of inferior stability and photoluminescence quantum yield (PL QY) in aqueous solution. Here, PL QY of 65% and excellent stability of InP/GaP/ZnS QD@SiO nanoparticles have been successfully synthesized a silica coating method. The containing thiol-capped hydrophobic InP/GaP/ZnS QDs were pre-silanized with waterless, ammonia-free hydrolysis tetraethyl orthosilicate, and subsequently, an outer silica shell was generated in the reverse microemulsion. The corresponding QD-based fluorescence-linked immunosorbent assay exhibits a high sensitivity of 0.9 ng mL for C-reactive protein and the broad detection range of 1-1000 ng mL, which was close to that of the state-of-the-art Cd-based QD@SiO nanoparticles and had the highest sensitivity of Cd-free QDs so far. This work provides a very successful silica coating method for the containing thiol-capped hydrophobic QDs and the QDs highly sensitive to water and oxygen, and the obtained InP/GaP/ZnS QD@SiO nanoparticles were considered as the robust, biocompatible, and promising Cd-free fluorescent labels for the further ultra-sensitive detection.
Topics: Biocompatible Materials; Enzyme-Linked Immunosorbent Assay; Fluorescent Antibody Technique; Indium; Particle Size; Phosphines; Quantum Dots; Silicon Dioxide
PubMed: 33847486
DOI: 10.1021/acs.inorgchem.1c00304 -
ACS Chemical Biology Apr 2016Helicobacter pylori and Campylobacter jejuni are human pathogens and causative agents of gastric ulcers/cancer and gastroenteritis, respectively. Recent studies have...
Helicobacter pylori and Campylobacter jejuni are human pathogens and causative agents of gastric ulcers/cancer and gastroenteritis, respectively. Recent studies have uncovered a series of proteases that are responsible for maintaining the helical shape of these organisms. The H. pylori metalloprotease Csd4 and its C. jejuni homologue Pgp1 cleave the amide bond between meso-diaminopimelate and iso-d-glutamic acid in truncated peptidoglycan side chains. Deletion of either csd4 or pgp1 results in bacteria with a straight rod phenotype, a reduced ability to move in viscous media, and reduced pathogenicity. In this work, a phosphinic acid-based pseudodipeptide inhibitor was designed to act as a tetrahedral intermediate analog against the Csd4 enzyme. The phosphinic acid was shown to inhibit the cleavage of the alternate substrate, Ac-l-Ala-iso-d-Glu-meso-Dap, with a Ki value of 1.5 μM. Structural analysis of the Csd4-inhibitor complex shows that the phosphinic acid displaces the zinc-bound water and chelates the metal in a bidentate fashion. The phosphinate oxygens also interact with the key acid/base residue, Glu222, and the oxyanion-stabilizing residue, Arg86. The results are consistent with the "promoted-water pathway" mechanism for carboxypeptidase A catalysis. Studies on cultured bacteria showed that the inhibitor causes significant cell straightening when incubated with H. pylori at millimolar concentrations. A diminished, yet observable, effect on the morphology of C. jejuni was also apparent. Cell straightening was more pronounced with an acapsular C. jejuni mutant strain compared to the wild type, suggesting that the capsule impaired inhibitor accessibility. These studies demonstrate that a highly polar compound is capable of crossing the outer membrane and altering cell shape, presumably by inhibiting cell shape determinant proteases. Peptidoglycan proteases acting as cell shape determinants represent novel targets for the development of antimicrobials against these human pathogens.
Topics: Campylobacter jejuni; Helicobacter pylori
PubMed: 26735022
DOI: 10.1021/acschembio.5b01039 -
European Journal of Medicinal Chemistry Nov 2021Given the increasing reports of well-defined bimetallic molecular complexes as potential anticancer agents in the last decades, along with the prevalence of platinum in... (Review)
Review
Given the increasing reports of well-defined bimetallic molecular complexes as potential anticancer agents in the last decades, along with the prevalence of platinum in anticancer therapy, we report here a detailed survey of bimetallic platinum and palladium complexes investigated as potential anticancer agents. Specifically, we will concentrate on the synthesis, characterisation and biological (anticancer) studies of a sub-class of these agents, namely homo and heterobimetallic complexes bearing a bridging phosphane ligand of the type: [LM(μ-RP(CH)PR)ML] (where M is platinum or palladium, M is any other transition metal, R = alkyl or aryl substituents, L or L are co-ligands, n = 1-6). We will review the in vitro and in vivo activities and any mechanistic anticancer studies of these complexes with a view of trying to delineate patterns in biological activity and structure-activity relationships (SAR). We do not include the review of bimetallic complexes in this class that have not undergone any anticancer testing, nor those that have been involved in other biological investigations unrelated to cancer studies.
Topics: Animals; Antineoplastic Agents; Cell Survival; Coordination Complexes; Humans; Ligands; Palladium; Phosphines; Platinum; Structure-Activity Relationship
PubMed: 34214843
DOI: 10.1016/j.ejmech.2021.113651 -
Molecules (Basel, Switzerland) Dec 2023Tris(hetaryl)substituted phosphines and their chalcogenides are promising polydentate ligands for the design of metal complexes. An experimental and theoretical...
Tris(hetaryl)substituted phosphines and their chalcogenides are promising polydentate ligands for the design of metal complexes. An experimental and theoretical conformational analysis of tris[2-(4-pyridyl)ethyl]phosphine, tris[2-(2-pyridyl)ethyl]phosphine, and their chalcogenides was carried out by the methods of dipole moments, IR spectroscopy and DFT B3PW91/6-311++G(df,p) calculations. In solution, these compounds exist as an equilibrium of mainly non-eclipsed (synclinal or antiperiplanar) forms with a predominance of a symmetrical conformer having a -orientation of the C-C bonds of pyridylethyl substituents relative to the P=X bond (X = lone pair, O, S, Se) and a -orientation of the pyridyl rings relative to the zigzag ethylene bridges. Regardless of the presence and nature of the chalcogen atom (oxygen, sulfur, or selenium) in the studied molecules with many axes of internal rotation, steric factors-the different position of the nitrogen atoms in the pyridyl rings and the configuration of ethylene bridges-determine the realization and spatial structure of preferred conformers.
PubMed: 38202693
DOI: 10.3390/molecules29010110 -
Scientific Reports May 2023The use of metal phosphides, particularly aluminum phosphide, poses a significant threat to human safety and results in high mortality rates. This study aimed to...
The use of metal phosphides, particularly aluminum phosphide, poses a significant threat to human safety and results in high mortality rates. This study aimed to determine mortality patterns and predictive factors for acute zinc and aluminum phosphide poisoning cases that were admitted to Menoufia University Poison and Dependence Control Center from 2017 to 2021. Statistical analysis revealed that poisoning was more common among females (59.7%), aged between 10 and 20 years, and from rural regions. Most cases were students, and most poisonings were the result of suicidal intentions (78.6%). A new hybrid model named Bayesian Optimization-Relevance Vector Machine (BO-RVM) was proposed to forecast fatal poisoning. The model achieved an overall accuracy of 97%, with high positive predictive value (PPV) and negative predictive value (NPV) values of 100% and 96%, respectively. The sensitivity was 89.3%, while the specificity was 100%. The F1 score was 94.3%, indicating a good balance between precision and recall. These results suggest that the model performs well in identifying both positive and negative cases. Additionally, the BO-RVM model has a fast and accurate processing time of 379.9595 s, making it a promising tool for various applications. The study underscores the need for public health policies to restrict the availability and use of phosphides in Egypt and adopt effective treatment methods for phosphide-poisoned patients. Clinical suspicion, positive silver nitrate test for phosphine, and analysis of cholinesterase levels are useful in diagnosing metal phosphide poisoning, which can cause various symptoms.
Topics: Female; Humans; Child; Adolescent; Young Adult; Adult; Aluminum; Bayes Theorem; Phosphines; Aluminum Compounds; Poisons; Heavy Metal Poisoning; Poisoning; Pesticides
PubMed: 37217491
DOI: 10.1038/s41598-023-34489-x