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Inorganic Chemistry Aug 2023Ferrocene-based phosphines equipped with additional functional groups are versatile ligands for coordination chemistry and catalysis. This contribution describes a new...
Synthesis, Structure, Reactivity, and Intramolecular Donor-Acceptor Interactions in a Phosphinoferrocene Stibine and Its Corresponding Phosphine Chalcogenides and Stiboranes.
Ferrocene-based phosphines equipped with additional functional groups are versatile ligands for coordination chemistry and catalysis. This contribution describes a new compound of this type, combining phosphine and stibine groups at the ferrocene backbone, viz. 1-(diphenylphosphino)-1'-(diphenylstibino)ferrocene (). Phosphinostibine and the corresponding P-chalcogenide derivatives PhP(E)fcSbPh (, fc = ferrocene-1,1'-diyl, E = O, S, Se) were synthesized and further converted to the corresponding stiboranes PhP(E)fcSb(OCCl)Ph ( and ) by oxidation with -chloranil. All compounds were characterized by spectroscopic methods, X-ray diffraction analysis, cyclic voltammetry, and theoretical methods. Both NMR spectroscopy and DFT calculations confirmed the presence of P → Sb and P═O → Sb donor-acceptor interactions in and , triggered by the oxidation of the stibine moiety into Lewis acidic stiborane. The corresponding interactions in and were of the same type but significantly weaker. A coordination study with AuCl as the model metal fragment revealed that the phosphine group acts as the "primary" coordination site, in line with its higher basicity. The obtained Au(I) complexes were applied as catalysts in the Au-catalyzed cyclization of -propargylbenzamide and in the oxidative [2 + 2 + 1] cyclization of ethynylbenzene with acetonitrile and pyridine -oxides. The catalytic results showed that the stibine complexes had worse catalytic performance than their phosphine counterparts, most likely due to the formation of weaker coordination bonds and hence poorer stabilization of the active metal species. Nevertheless, the stibine moiety could be used to fine-tune the properties of the ligated metal center by changing the oxidation state or substituents at the "remote" Sb atom.
PubMed: 37566394
DOI: 10.1021/acs.inorgchem.3c02075 -
RSC Advances Jul 2020Phosphonopeptides are mimetics of peptides in which phosphonic acid or related (phosphinic, phosphonous ) group replaces either carboxylic acid group present at... (Review)
Review
Phosphonopeptides are mimetics of peptides in which phosphonic acid or related (phosphinic, phosphonous ) group replaces either carboxylic acid group present at C-terminus, is located in the peptidyl side chain, or phosphonamidate or phosphinic acid mimics peptide bond. Acting as inhibitors of key enzymes related to variable pathological states they display interesting and useful physiologic activities with potential applications in medicine and agriculture. Since the synthesis and biological properties of peptides containing C-terminal diaryl phosphonates and those with phosphonic fragment replacing peptide bond were comprehensively reviewed, this review concentrate on peptides holding free, unsubstituted phosphonic acid moiety. There are two groups of such mimetics: (i) peptides in which aminophosphonic acid is located at C-terminus of the peptide chain with most of them (including antibiotics isolated from bacteria and fungi) exhibiting antimicrobial activity; (ii) non-hydrolysable analogues of phosphonoamino acids, which are useful tools to study physiologic effects of phosphorylations.
PubMed: 35518575
DOI: 10.1039/d0ra04655h -
Chemistry (Weinheim An Der Bergstrasse,... Nov 2020Metalation of secondary diaminophosphine boranes by alkali metal amides provides a robust and selective access route to a range of metal diaminophosphide boranes M[(R N)...
Metalation of secondary diaminophosphine boranes by alkali metal amides provides a robust and selective access route to a range of metal diaminophosphide boranes M[(R N) P(BH )] (M=Li, Na, K; R=alkyl, aryl) with acyclic or heterocyclic molecular backbones, whereas reduction of a chlorodiaminophosphine borane gave less satisfactory results. The metalated species were characterized in situ by NMR spectroscopy and in two cases isolated as crystalline solids. Single-crystal XRD studies revealed the presence of salt-like structures with strongly interacting ions. Synthetic applications of K[(R N) P(BH )] were studied in reactions with a 1,2-dichlorodisilane and CS , which afforded either mono- or difunctional phosphine boranes with a rare combination of electronegative amino and electropositive functional disilanyl groups on phosphorus, or a phosphinodithioformate. Spectroscopic studies gave a first hint that removal of the borane fragment may be feasible.
PubMed: 32567741
DOI: 10.1002/chem.202002296 -
IUCrData Apr 2023The title hydrate, MePO·2HO, crystallizes in the ortho-rhom-bic space group with eight formula units per unit cell. The extended structure displays O-H⋯O hydrogen...
The title hydrate, MePO·2HO, crystallizes in the ortho-rhom-bic space group with eight formula units per unit cell. The extended structure displays O-H⋯O hydrogen bonding, with MePO mol-ecules as acceptors and water mol-ecules acting as donors and acceptors of hydrogen bonds, forming hydrogen-bonded layers, which propagate in the plane.
PubMed: 37151205
DOI: 10.1107/S2414314623003140 -
RSC Advances Feb 2021The Sonogashira reaction is a cross-coupling reaction of a vinyl or aryl halide with a terminal alkyne to form a C-C bond. In its original form, the Sonogashira reaction... (Review)
Review
The Sonogashira reaction is a cross-coupling reaction of a vinyl or aryl halide with a terminal alkyne to form a C-C bond. In its original form, the Sonogashira reaction is performed with a palladium species as a catalyst while co-catalyzed by a copper species and a phosphine or amine. The reaction is conducted under mild conditions, , room temperature, aqueous solutions, and the presence of mild bases. Undeniably, the Sonogashira reaction is among the most competent and efficient reactions widely used in organic synthesis. This named reaction has proved useful in many organic synthesis areas, including the synthesis of pharmaceuticals, heterocycles, natural products, organic compounds, complex molecules having biological activities, nanomaterials, and many more materials that we use in our daily lives. The presence of transition metals as a catalyst was indeed essential in the Sonogashira reaction. However, recently, the reaction has been successfully conducted without copper as a co-catalyst and phosphines or amines as bases. In this critical review, we have focused on developments in the Sonogashira reaction successfully performed in the absence of copper complexes, phosphines or amines, which could be of particular advantage in implementing green chemistry principles and making the reactions more achievable from an economic viewpoint.
PubMed: 35423221
DOI: 10.1039/d0ra10575a -
Fa Yi Xue Za Zhi Apr 2022To study the distribution of total phosphine in phosphine poisoning victims and summarize the characteristics of phosphine poisoning cases.
OBJECTIVES
To study the distribution of total phosphine in phosphine poisoning victims and summarize the characteristics of phosphine poisoning cases.
METHODS
The phosphine and its metabolites in the biological samples of 29 victims in 16 phosphine poisoning cases were qualified and quantified by headspace gas chromatography-mass spectrometry.
RESULTS
Five victims among 29 were poisoned by ingestion of aluminium phosphide and 24 by inhalation of phosphine gas. Phosphine metabolites were detected in the biological samples of 23 victims, and the concentrations of total phosphine in blood ranged 0.5-34.0 μg/mL. The total concentration of phosphine in liver tissue was up to 71.0 μg/g. Phosphine was not detected in the blood of the other six survived victims, which may be related to the small amount of phosphine exposure and the delay in blood sampling.
CONCLUSIONS
The total concentration of phosphine in blood and tissues caused by aluminum phosphine ingestion is higher than that caused by phosphine gas inhalation. The death cases of phosphine inhalation are characterized by long exposure time, repeated exposures and age susceptibility.
Topics: Aluminum Compounds; Gas Chromatography-Mass Spectrometry; Humans; Liver; Phosphines; Poisoning
PubMed: 35899515
DOI: 10.12116/j.issn.1004-5619.2020.300901 -
Molecules (Basel, Switzerland) May 2022α-Aminophosphonates, -phosphinates, and -phosphine oxides are a group of organophosphorus compounds that were investigated as extraction agents for rare earth (RE)... (Review)
Review
α-Aminophosphonates, -phosphinates, and -phosphine oxides are a group of organophosphorus compounds that were investigated as extraction agents for rare earth (RE) metals and actinoids for the first time in the 1960s. However, more systematic investigations of their extraction properties towards REs and actinoids were not started until the 2010s. Indeed, recent studies have shown that these α-amino-functionalized compounds can outperform the commercial organophosphorus extraction agents in RE separations. They have also proven to be very efficient extraction and precipitation agents for recovering Th and U from RE concentrates. These actinoids coexist with REs in some of the commercially important RE-containing minerals. The efficient separation and purification of REs is becoming more and more important every year as these elements have a pivotal role in many existing technologies. If one also considers the facile synthesis of α-amino-functionalized organophosphorus extractants and precipitation agents, it is expected that they will be increasingly utilized in the extraction chemistry of REs and actinoids in the future. This review collates α-aminophosphonates, -phosphinates, and -phosphine oxides that have been utilized in the separation chemistry of REs and actinoids, including their most relevant synthetic routes and molecular properties. Their extraction and precipitation properties towards REs and actinoids are also discussed.
Topics: Actinoid Series Elements; Metals, Rare Earth; Organophosphonates; Oxides; Phosphines; Thorium; Uranium
PubMed: 35684403
DOI: 10.3390/molecules27113465 -
Beilstein Journal of Organic Chemistry 2020Diverse P,N-phosphine ligands reported to date have performed exceptionally well as auxiliary ligands in organometallic catalysis. Phosphines bearing 2-pyridyl moieties... (Review)
Review
Diverse P,N-phosphine ligands reported to date have performed exceptionally well as auxiliary ligands in organometallic catalysis. Phosphines bearing 2-pyridyl moieties prominently feature in literature as compared to phosphines with five-membered N-heterocycles. This discussion seeks to paint a broad picture and consolidate different synthetic protocols and techniques for N-heterocyclic phosphine motifs. The introduction provides an account of P,N-phosphine ligands, and their structural and coordination benefits from combining heteroatoms with different basicity in one ligand. The body discusses the synthetic protocols which focus on P-C, P-N-bond formation, substrate and nucleophile types and different N-heterocycle construction strategies. Selected references are given in relation to the applications of the ligands.
PubMed: 32256853
DOI: 10.3762/bjoc.16.35 -
Pharmaceuticals (Basel, Switzerland) May 2023Metal complexes feature a wide range of available geometries, diversified lability, controllable hydrolytic stability, and easily available rich redox activity. These... (Review)
Review
Metal complexes feature a wide range of available geometries, diversified lability, controllable hydrolytic stability, and easily available rich redox activity. These characteristics, combined with the specific properties of coordinated organic molecules, result in many different mechanisms of biological action, making each of the myriads of the classes of metal coordination compounds unique. This focused review presents combined and systematized results of the studies of a group of copper(I) (pseudo)halide complexes with aromatic diimines and tris(aminomethyl)phosphines of a general formula [CuX(NN)PR], where X = I or NCS, NN = 2,2'-bipyridyl, 1,10-phenanthroline, 2,9-dimethyl-1,10-phenanthroline or 2,2'-biquinoline, and PR = air-stable tris(aminomethyl)phosphines. The structural and electronic properties of the phosphine ligands and luminescent complexes are discussed. The complexes with 2,9-dimethyl-1,10-phenanthroline, apart from being air- and water-stable, exhibit a very high in vitro antimicrobial activity against the and . Moreover, some of these complexes also show a strong in vitro antitumor activity against human ovarian carcinoma cell lines: MDAH 2774 and SCOV 3, CT26 (mouse colon carcinoma), and A549 (human lung adenocarcinoma) cell lines. The tested complexes are moderately able to induce DNA lesions through free radical processes, however the trends do not reflect observed differences in biological activity.
PubMed: 37242549
DOI: 10.3390/ph16050766 -
Molecules (Basel, Switzerland) Sep 2022This study investigates the mechanism of metal-free pyridine phosphination with P(OEt), PPh, and PArCF using density functional theory calculations. The results show...
This study investigates the mechanism of metal-free pyridine phosphination with P(OEt), PPh, and PArCF using density functional theory calculations. The results show that the reaction mechanism and rate-determining step vary depending on the phosphine and additive used. For example, phosphination of pyridine with P(OEt) occurs in five stages, and ethyl abstraction is the rate-determining step. Meanwhile, 2-Ph-pyridine phosphination with PPh is a four-step reaction with proton abstraction as the rate-limiting step. Energy decomposition analysis of the transition states reveals that steric hindrance in the phosphine molecule plays a key role in the site-selective formation of the phosphonium salt. The mechanism of 2-Ph-pyridine phosphination with PArCF is similar to that with PPh, and analyses of the effects of substituents show that electron-withdrawing groups decreased the nucleophilicity of the phosphine, whereas aryl electron-donating groups increased it. Finally, TfO plays an important role in the C-H fluoroalkylation of pyridine, as it brings weak interactions.
Topics: Catalysis; Electrons; Metals; Models, Theoretical; Pyridines
PubMed: 36080460
DOI: 10.3390/molecules27175694