Phosphorus Esters Research Articles

Synthesis and complexation of amphiphilic calix[4]arene phosphonates with organic molecules in solutions and Langmuir-Blodgett films

A family of amphiphilic alkoxycalix[4]arenes bearing phosphonyl groups directly attached to para positions of the aromatic rings is synthesized by the Arbuzov reaction of para-bromoalkoxycalix[4]arenes with alkyl esters of phosphorus (III) acid in the presence of NiBr 2. Amphiphilicity of the calixarene phosphonates is controlled by varying the quantities of the hydrophilic phosphoryl groups at the upper rim and the hydrophobic alkyl groups at the lower rim. Complexation of the calixarenes with benzene derivatives and iso-butanol in solutions is studied by RP HPLC and IR spectroscopy methods. Langmuir-Blodgett films of the calixarene phosphonates are prepared. Physical characteristics and complexation of the films with volatile organic molecules are characterized.

Phosphorus-containing small rings: XII. Reaction of 3-phenyl-2,2-dichlorocyclobutanone with esters and amidoesters of phosphorus(III) acids

The esters of phosphorus(III) acids are known to react readily with α-halocarbonyl compounds to form vinyl esters of the phosphorus(IV) acid [2, 3]. According to published data, halocyclobutanones have not been used in this reaction. In this connection, aiming to develop a synthetic approach to the phosphorus-containing cyclobutanones, we studied the reaction of 3phenyl-2,2-dichlorocyclobutanone I with the esters and amidoesters of phosphorus(III) acids. The reaction progress was monitored by tracing the amount of chloroalkanes released and also by means of TLC. It was shown that depending on the nature of the phosphorus component the reaction temperature should be varied within 80–130°С. Arylphosphonites are the most active, and amidoesters, the least active. The reaction products were purified by vacuum distillation or by column chromatography. Their structure was studied by IR, Н and Р NMR spectroscopy. By the spectral data, this reaction proceeds as the Perkov reaction [3] without the opening of the four-membered ring. DOI: 10.1134/S1070363210120224

ChemInform Abstract: Synthesis of Organophosphorus Compounds in Terms of Elemental Phosphorus, Sulfur and Their Derivatives

We have developed new facile methods for synthesizing various organophosphorus compouds on the basis of elemental phosphorus and sulfur, phosphorus sulfides and esters of thiophosphorous acids.

Dissolved inorganic and organic phosphorus uptake in Trichodesmium and the microbial community: The importance of phosphorus ester in the Sargasso Sea

The dynamics and relative importance of inorganic phosphate (Pi) and dissolved organic phosphorus (DOP) uptake were examined in Trichodesmium and the microbial community. Trichodesmium DOP and Pi uptake rates were also compared to literature values from several other taxonomically important groups in the Sargasso Sea. Uptake rates and uptake kinetics of 33Pi and DOP (using alpha‐labeled adenosine‐5′‐triphosphate 33P‐ATP as a model P ester compound) were assayed during two cruises. The in situ uptake rates suggest that the contribution of P ester to total P uptake can be greater than 25% for Trichodesmium, the microbial community, and key phytoplankton groups (Prochlorococcus, Synechococcus, picoeukaryotes, and nanoeukaryotes), depending on the location. Based on the kinetics of Pi uptake and P ester uptake, Trichodesmium is a poor competitor for Pi but a much better competitor for P esters as compared to the microbial community. Trichodesmium growth rates calculated from the Pi and P ester uptake parameters suggest that only a small fraction of the P ester pool needs to be bioavailable to allow reasonable growth rates. These data underscore the importance of P esters in supporting production by Trichodesmium in the Sargasso Sea, and provide the first in situ measurements of P ester uptake and uptake kinetics in this important N2‐fixing genus.

Physical Image vs. Structure Relation, Part 131: Calculational Evidences for the 2h J PH Spin–Spin Coupling in Internally H-Bonded Isomers of Some 1-Oxoalkanephosphonate Hydrazones

The P(IV)↔H spin–spin transfer across the N─H· · · O−−P+ intramolecular H-bond previously observed NMR spectroscopically for Z stereoisomers of hydrazones of O,O′ -diisopropyl 1-oxoalkanephosphonates, 2h J PH = 2.95 ± 0.35 Hz, was rationalized using Fermi-contact (FC) contributions to such J PH couplings. Moreover, the FC terms were found to be dominant terms of these 2h J PH couplings. The applied FPT-DFT(B3LYP) FC calculational approach was successfully tested on J PH couplings in model phosphorus esters. As a result, linear relation J PH obsd (CDCl3) vs. J FC PH calcd was established for different long-range J PH couplings occurring via an oxygen atom of the phosphoryl group.

Studies on the Efficient Generation of PhosphorusCarbon Bonds via a Rearrangement of PIII Esters Catalysed by Trimethylhalosilanes

Halotrimethylsilanes Me(3)SiX (X = Br, I) catalyse rearrangements of tricoordinate phosphorus esters R'R''P-OR into the corresponding phosphoryl systems R'R''P(O)R. This provides a simple and efficient route to a variety of structures containing phosphorus-carbon bonds, under mild conditions and with good yields. The reaction mechanism was investigated in detail by (31)P NMR spectroscopy and independent synthesis of the reaction intermediates. It has been demonstrated that the primary products of this catalytic reaction are halogeno P(III) structures R'R''PX and silyl ethers ROSiMe(3) and that they subsequently react to give the corresponding phosphorus silyl esters-Me(3)SiOPR'R''-and alkyl halides RX. At higher temperatures these intermediates then react to form R'R''P(O)R compounds. This paper also features the surprising observation that when esters Ph(2)POR and halotrimethylsilanes Me(3)SiX (X = Br, I) are used in 2:1 ratio, phosphonium salts Ph(2)R(2)P(+)X(-) and trimethylsilyl diphenylphosphinate--Ph(2)P(O)OSiMe(3)--are formed as the major products. Experimental evidence indicates that the mechanisms of both reactions are fundamentally different from that of the Michaelis-Arbuzov reaction. Me(3)SiCl is not reactive and this paper explains why.

Synthesis of tervalent phosphorus esters in biphasic system using potassium phosphate as unique solid base

AbstractThe synthesis of tervalent phosphorus esters continues to be a significant area of interest, much of it again directed toward the synthesis of phosphite ligands for metal‐catalyzed reactions. Typically, they were obtained through esterification of the corresponding phosphorus chlorides with the appropriate alcohols in the presence of an amine. In this paper, we present a new method for the synthesis of tervalent phosphorus esters, not yet mentioned in the literature, when potassium phosphate, as a unique base, is used in liquid–solid system. Symmetrical and unsymmetrical phosphites were obtained with good yields (65%–80%) using this method. The compounds were characterized by 31P NMR spectroscopy. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:360–364, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20438

Dehydrochlorination of 4-hydroxy-3,5-di-tert-butylbenzylidene chloride with aprotic nonionogenic reagents

47 We showed previously that 4-hydroxy-3,5-ditertbutylbenzylidene chloride ( I ) reacted with nonionogenic aprotic reagents, such as triethyl orthoformate ( II ) [1] and esters of phosphorus(III) acids ( III ) [2], via nucleophilic displacement and underwent dechloroalkoxylation and dechlorophosphorylation to form acetal and diphosphonate, respectively. We studied previously unknown reactions of gemdichloride I with ethylene oxide ( IV ), vinyl ethyl ether ( V ), N , N , N ', N 'tetramethylmethanediamine ( VI ), and dimethyl(4hydroxy-3,5-ditertbutylbenzyl)amine ( VII ). The aim of this study is to establish the structure of reaction products and to determine the general reaction scheme and reaction conditions. We have found that, as distinct from reagents II and III , compounds IV – VII show dehydrochlorinating ability toward gemdichloride I . The main reaction product is 4-chloromethylene-2,6-ditertbutylcyclohexadien-2,5-one VIII . The coproducts of the reaction are ethylene chlorohydrin ( IX ), 1-chloro-1-ethoxyethane ( X ), dimethylamine hydrochloride ( XI ), dimethyl(chloromethyl)amine ( XII ), and amine hydrochloride XIII , respectively.

Supramolecular catalytic systems based on anionic amphiphiles and polyethyleneimine for hydrolytic cleavage of phosphorus ester bonds

Self-organization in individual and binary systems based on polyethyleneimine (PEI) and amphiphilic sulfonatocalix[4]resorcinarene was studied by conductometry, tensiometry, dynamic light scattering, and 1H NMR spectroscopy. The critical concentrations of micelle formation and aggregate sizes were determined. The enhancement of the catalytic effect on the hydrolysis of O-ethyl O-p-nitrophenyl chloromethylphosphonate was shown in the following series of the systems: PEI-water < PEI—calixarene-water < PEI—calixarene—LaIII—water.

Ionic-liquid-promoted Michaelis–Arbuzov rearrangement

Room-temperature imidazolium ionic liquids, [Rmim][X], proved to be environmentally benign recyclable solvents promoting the Michaelis–Arbuzov rearrangement, which can be performed even at room temperature in a short period of time. The best ionic liquid of choice depended on the starting phosphorus(III) ester, namely, for triethyl phosphite [bmim][NTf2] demonstrated better results while for ethyl diphenylphosphinite it was [hmim][Br].

(New findings on phosphate uptake in plants – a literature survey)

Phosphate uptake calculated with a mechanistic model fitted relatively well with the measured uptake in several cultivated plants when the soil P content was high. At low soil P content the plants took up more P than calculated. Some reasons for that are among others physiological reactions of the roots, which do change the P availability in the rhizosphere: I. Increased exudation of phosphatases, in particular phytase release phosphorus from phosphorus esters which can be used by the plants. Transgene Trifolium subterraneum plants with a phytase gen from Aspergillus niger displayed a clearly improved phosphorus nutritional status when supplied with phytate. II. Dicotyledonous plants (f.e. lupins, red clover, alfalfa, sugar beet and spinach) exude increased amounts of low molecular organic anions (citrate, malate, oxalate, a.o.) per unit root length at low P-supply. These molecules release phosphorus ions from hydrated Fe/Al oxids bound phosphate among other by ligand exchange, which then is plant available. Transgene eucalyptus plants containing a citrate synthetase (CS) gene from carrot express higher levels of CS, exude more citrate and improve the P nutritional status of an Andosol. In carrots, pieces of DNA coding for P transporters (DcPT1, DcPT2) were characterized and their expression was quantified by mRNA in cross offsprings. In rice, four putative quantitative trait loci (QTLs) for P uptake on four different chromosomes were characterized and assigned to according markers. They were crossed from an Indian variety into a Japanese one and detected there. In this way P uptake could substantially be improved in isogenic lines. The marker assisted crossing of quantitative traits like P uptake and the gene transfer with the aim of P-mobilization in the rhizosphere were regarded as useful tools for increasing P-uptake by the according authors. These findings are especially relevant for soils with high content of total P but low in P availability. Neuere Erkenntnisse zur Phosphataufnahme von Pflanzen – Literaturbefunde1 Stichwörter Phosphataufnahme, Phosphatmobilisierung, Phosphattransporter, Phosphatase, Phytase, Exsudation organischer Säuren, Gentransfer, Ligandenaustausch, Modellierung der Phosphataufnahme. Zusammenfassung 1Nach einem Vortrag an der Sächsischen Landesanstalt fü r Landwirtschaft zur Verabschiedung von Lothar Suntheim aus dem Berufsleben am 15. April 2005. Die mit einem mechanistischen Modell berechnete P-Aufnahme verschiedener Kulturpflanzen stimmte dann mit der gemessenen relativ gut überein, wenn die P-Gehalte in den Böden hoch war. Bei niedrigen Boden-P-Gehalten nahmen die Pflanzen mehr P auf als berechnet. Wichtige Ursachen dafür sind u.a. physiologische Reaktionen der Wurzeln, die die P-Verfügbarkeit in der Rhizosphäre verändern: I. Die erhöhte Exsudation von Phosphatasen, insbesondere Phytase setzt Phosphat aus Phosphorsäureestern frei, das von den Pflanzen genutzt wird. Transgene Trifolium subterraneum-Pflanzen mit einem Phytasegen aus Aspergillus niger zeigten bei Phytaternährung eine deutliche Verbesserung ihres P-Ernährungszustandes. II. Dikotyle Pflanzen (z.B. Lupinen, Rotklee, Weißklee, Luzerne, Zuckerrüben, Spinat) exsudierten bei niedrigem P-Angebot verstärkt niedermolekulare organische Anionen (Citrat, Malat, Oxalat, u.a.) je Einheit Wurzellänge. Diese Moleküle setzen im Boden Phosphationen u.a. durch Ligandenaustausch aus an Fe/Al-Oxidhydraten sorbiertem Phosphat frei, das von Pflanzen aufgenommen werden kann. Transgene Eukalyptuspflanzen mit einem Citratsynthetase (CS)-Gen aus Möhre exprimierten verstärkt die CS, exsudierten mehr Citrat und verbesserten ihren P-Ernährungszustand auf einem Andosol in Folge der P-Mobilisierung im Boden. Bei Möhren wurden Abschnitte auf der DNA für die Codierung von Phosphattransportern (DcPT1, DcPT2) charakterisiert und ihre Expression in Kreuzungsnachkommen über die mRNA quantifiziert. In Reis wurden 4 putative quantitative Merkmalsorte (QTLs) für die Phosphataufnahme auf 4 Chromosomen charakterisiert und entsprechenden Markern zugeordnet. Sie wurden aus einer indischen Sorte in eine japanische eingekreuzt und wiedergefunden. Damit konnte in isogenen Reislinien die P-Aufnahmeeffizienz deutlich erhöht werden. Insgesamt ergibt sich, dass die markergestützte Einkreuzung von quantitativen Merkmalen wie der P-Aufnahme und der Gentransfer von bestimmten Merkmalen, die am Ende der P-Mobilisierung im Boden dienen, von den betreffenden Autoren als nützliche Mittel zur Verbesserung der P-Aufnahme angesehen werden. Damit ergeben sich neue positive Perspektiven für die Nutzung von Böden mit relativ hohen Gesamt-P-Gehalten, aber geringer P-Verfügbarkeit.

Synthesis of thiazole aminophosphine oxides, aminophosphonic and aminophosphinic acids and Cu(II) binding abilities of thiazole aminophosphonic acids

A series of new aminophosphine oxides, aminophosphonic and aminophosphinic acids derived from thiazole was synthesized by addition of phosphine oxides or silylated phosphorus esters to the corresponding thiazole aldimines. The thiazole aldimines were obtained from 2-thiazole aldehyde and primary amines by a standard procedure. The corresponding phosphine oxides were obtained by alkylation of diethyl phosphite or ethyl phenylphosphinate with the appropriate Grignard reagents. The silylated phosphorus esters were prepared from trimethyl phosphite and from methyl- or phenylphosphinic ethyl ester by treatment with bromotrimethylsilane. The coordination ability towards Cu(II) ions are described for two obtained aminophosphonate ligands.

Surface‐Mediated Solid Phase Reactions: A Simple, Efficient and Base‐Free Synthesis of Phosphonates and Phosphates on Al2O3.

Al2O3-supported solvent free condensation of alkylphosphonic dichlorides with alcohols at room temperature yielded phosphorus esters in excellent yields.

Oxidative Alkoxylation of Red Phosphorus in the Presence of the FeCl3-I2 Catalytic System

A new effective catalytic system FeCl3-I2 was found, that allows the direct oxidative alkoxylation of red phosphorus to trialkyl phosphates to be performed with high rate and selectivity at 60–80°C. Kinetics of the process were studied, and a separate redox mechanism of the process and a scheme of formation of phosphorus esters were offered. Kinetic and activation parameters of the reaction are calculated.

Oxime reactivation of acetylcholinesterase inhibited by toxic phosphorus esters: in vitro kinetics and thermodynamics

Owing to the threat of organophosphate exposures, not only to pesticides but also to nerve agents, it is very important to know the whole process of organophosphates-inhibited acetylcholinesterase (AChE, EC 3.1.1.7) reactivation. Although current antidotes against organophosphorus intoxications consist also of prophylactics, AChE reactivators are still needed especially in the case of intoxications with high doses of organophosphates, for which prophylactic treatment is not effective. For this reason, new AChE reactivators are still being developed. Our work summarizes accurately the whole reactivation process, and offers some help for scientists who are interested in the area of AChE reactivation.

Use of Phosphorus Ligand NMR Probes To Investigate Electronic and Second-Sphere Solvent Effects in Ligand Substitution Reactions at Manganese(II) and Manganese(III)

Manganese/ligand association dynamics were studied using a series of structurally related anionic phosphorus ester ligand probes [CH(3)OP(O)(X)(Y)(-), where X = CH(3)O, CH(3)CH(2), or H and Y = O, S, or BH(3)]. Reactions of the probe ions with Mn(H(2)O)(6)(2+) and a manganese(III) porphyrin (Mn(III)TMPyP(5+)) were studied in aqueous solution by paramagnetic (31)P NMR line-broadening techniques. A satisfactory linear free energy relationship for reactions of the probe ions with Mn(H(2)O)(6)(2+) and Mn(III)TMPyP(5+) required consideration of both the basicity and solvent affinity of the probe ligands: log(k(app)) = log(k(0)) + alpha pK(a) + beta log(K(ext)), where k(0), alpha, and beta are metal complex dependent parameters and pK(a) and K(ext) represent the measured Bronsted acidity and water/n-butanol extraction constant for the probe anions, respectively. Reactions of Mn(H(2)O)(6)(2+) were relatively insensitive to changes in ligand basicity (alpha = -0.04) and favored the more hydrophilic anions (beta = -0.54). These observations are consistent with a dissociative ligand exchange mechanism wherein the outer-sphere complex is stabilized by hydrogen bonding between Mn(H(2)O)(6)(2+) and the incoming ligand. In contrast, reactions with Mn(III)TMPyP(5+) are accelerated by decreases in both the basicity (alpha = -0.43) and the hydrophilicity (beta = +0.97) of the probe. We conclude that reactions of Mn(III)TMPyP(5+) are also dissociative but that the aromatic groups of the porphyrin provide a hydrophobic environment surrounding the ligand binding site in Mn(III)TMPyP(5+). Thus, the probe/water solvent interactions must be significantly weakened in order to form the outer-sphere complex that leads to ligand substitution. This work demonstrates the utility of phosphorus relaxation enhancement (PhoRE) techniques for characterizing the second coordination sphere environment of metal complexes leading to ligation and will allow comparison of the second coordination spheres of Mn(H(2)O)(6)(2+) and Mn(III)TMPyP(5+) to those of other metal complexes.

Surface-mediated Solid Phase Reactions: A Simple, Efficient and Base-free Synthesis of Phosphonates and Phosphates on Al2O3

Al2O3-supported solvent free condensation of alkylphosphonic dichlorides with alcohols at room temperature yielded phosphorus esters in excellent yields.

Synthesis of phosphorus esters by transesterification mediated by N-heterocyclic carbenes (NHCs)

The versatile nucleophilic organic catalysts N-heterocyclic carbenes (NHCs) have been shown to effectively mediate the transesterification of phosphorus esters under mild conditions; user-friendly imidazolium salts can also be employed as pre-catalysts.

New chemistry and stereochemistry of tricoordinate phosphorus esters containing phosphorus–fluorine bond

The use of O-arylphosphoroamidites in the synthesis of nucleosides phosphates of biological interest and their P–F analogues is described. This goal is achieved by extremely smooth reaction of O-arylphosphites with fluoride anion donors. Dinucleoside phosphorofluoridites RO(R′O)PF prepared by this method can be resolved into diastereoisomeric forms. Phosphorofluoroamidites –P(F)NR 2 are efficient reagents in the synthesis of corresponding esters –P(F)OR′. These P(III)–F systems are employed in a new and effective synthesis of trifluoromethylphosphonite P(III)–CF 3 by reaction with (trifluoromethyl)trimethylsilane (CF 3SiMe 3). This reaction, catalysed by the fluoride anion, can be part of a sequential procedure that combines formation of P(III)–F compounds with their transformation into the corresponding P(III)–CF 3 system. To cite this article: J. Michalski et al., C. R. Chimie 7 (2004) .

Catalytic effect of supramolecular system based on cationic surfactant and monopodands in nucleophilic substitution of phosphorus esters

The data are presented on the synthesis of podands with terminal quinoxaline fragments of rings and their influence on both the micellization properties of cetyltrimethylammonium bromide in a water—DMF solution and kinetics of basic hydrolysis of O-p-nitrophenyl O-ethyl chloromethylphosphonate and O-p-nitrophenyl O-hexyl chloromethylphosphonate in the absence and presence of surfactants. The mechanism of the podand effect on the reaction rate depends on the structures of phosphonate and podand. 1,8-Bis(3-ethyl-1,2-dihydro-2-oxoquinoxalin-1-yl)-3,6-dioxaoctane inhibits the basic hydrolysis of the substrates to 3—4 times. In a micellar solution of the surfactant, an approximately 20-fold acceleration of the reaction rate constant is observed. The observed rate constant decreases when podand is added to a micellar solution. The catalytic effect of the polycomponent system is due to concentrating of the reactants. The micellar microenvironment can exert both positive and negative effects on the reactivity of phosphonates.