- The local structure of triphenyl phosphite studied using spallation neutron and high-energy X-ray diffraction
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Spallation neutron and high-energy X-ray diffraction experiments have been performed to investigate the local structural changes in triphenyl phosphite (TPP) in the crystalline, glacial, glassy, and supercooled liquid phases. The hydrogen/deuterium first-order difference method shows a large increase in intensity due to additional hydrogen correlations in the crystalline spectra compared to the glass and supercooled liquid at a??3.0 and 3.4 Aì?. These features are shown to be largely due to inter-phenyl ring H-C/H interactions, which are probably associated in part with the formation of weak intermolecular hydrogen bonds. The high-energy X-ray diffraction data show a decrease in correlations at 3.12 Aì? which is attributed to changes in C-O/P intramolecular interactions between the glacial and crystalline forms. The structural evolution of the glacial state was also measured over time using total neutron diffraction. The largest structural differences between the early glacial and crystalline states are observed at 3.0 and 4.5 Aì?. Moreover, as the transformation progresses, the glacial spectra cannot be adequately described as a simple mixture of supercooled liquid and crystalline components. These results suggest that changes in molecular conformation and nearest-neighbor interactions are responsible for the existence of the glacial state.
- Mei, Qiang,Ghalsasi, Prasanna,Benmore, Chris J.,Yarger, Jeffery L.
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- LIGAND DISSOCIATION FROM MONO-SUBSTITUTED DERIVATIVES OF HEXACARBONYLCHROMIUM (Cr(CO)5L, L = P(C6H5)3, P(C4H9)3, P(OCH3)3, P(OC6H5)3, AND As(C6H5)3)
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The rates of dissociation of the unique ligand from Cr(CO)5L have been determined for L = P(C6H5)3, P(OC6H5)3, P(OCH3)3, and As(C6H5)3 by reaction with CO.The reactions were investigated from 80-140 deg C and activation parameters were determined.The rate
- Wovkulich, Michael J.,Atwood, Jim D.
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- Ruthenium-catalyzed regio- And site-selective: Ortho C-H borylation of phenol derivatives
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Efficient synthesis of o-borylphenols is achieved through the Ru-catalyzed regio- and site-selective sp2 C-H borylation of aryl diphenylphosphinites followed by removal of the phosphorus directing group. A successful application to aryl phosphites enables practical one-pot borylation of phenols, demonstrating high synthetic utility of this protocol.
- Homma, Yuki,Fukuda, Kazuishi,Iwasawa, Nobuharu,Takaya, Jun
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- Selective deoxygenation of aryl selenoxides by triaryl phosphites. Evidence for a concerted transformation
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Triaryl phosphites selectively reduce aryl selenoxides to selenides. The Hammett plot of the reactions of para-phenyl substituted triaryl phosphites with diphenyl selenoxide gave ρ=+2.3, whereas with bis(p-methoxyphenyl) selenoxide, ρ=-2.1. The results are consistent with a concerted mechanism for the oxygen transfer from Se to P.
- Stratakis, Manolis,Rabalakos, Constantinos,Sofikiti, Nikoletta
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- Reactions of η2-Acyl Ligands in Tp'(CO)2Mo2-C(O)R> Complexes To Form Complexed Enolates and Enones, Allyls, and Alkyne Insertion Products
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Elaboration of the η2-acyl ligand in hydridotris(3,5-dimethylpyrazolyl)borate (Tp') complexes of the type Tp'(CO)2Mo2-C(O)R> (R=Me, Et) has been accomplished by deprotonation to form enolates which react with electrophiles such as MeI, PhCH2Br, and PhCHO.Two enolate complexes, K and K, have been characterized by NMR spectroscopy.Photolysis of an acetonitrile solution of the achiral dicarbonyl reagent, Tp'(CO)2Mo2-C(O)R>, followed by addition of triphenyl phosphite forms racemic Tp'(CO)Mo.Excellent diastereoselectivity characterizes the addition of benzyl bromide (BzBr) to the enolate of Tp'(CO)Mo2-C(O)CH2CH3>; the Tp'(CO)Mo(η2-C(O)CHMeBz) product has been structurally characterized.Condensation of enolate complexes with benzaldehyde or benzophenone produces unsaturated η2-enone complexes.The structure of Tp'(CO)2Mo2-C(O)CH=CPh2> is reported.The η2-enone complexes undergo conjugate addition reactions to form saturated η2-acyl products, e.g., nucleophilic addition of MeLi to Tp'(CO)2Mo(η2-C(O)CH=CHPh) followed by acidification yields Tp'(CO)2Mo2-C(O)CH2CHMePh>.Heating Tp'(CO)2Mo(η2-C(O)CMe=CHPh) in toluene yields a ?-allyl complex, Tp'(CO)2Mo(η3-CH2CHCHPh).Insertion of alkynes (RCCR, R = Et or Ph) into the metal-carbon bond of the η2-acyl ligand in Tp'(CO)(CH3CN)Mo(η2-C(O)Et) under carbon monoxide forms oxametallacycles of the Tp'(CO)2Mo(CRCRC(O)Et) (R = Et or Ph).The structure of Tp'(CO)2Mo(CEtCEt(O)Et) has been determined.
- Rusik, C.A.,Collins, M.A.,Gamble, A.S.,Tonker, T.L.,Templeton, J.L.
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- The Synthesis and Mechanistic Considerations of a Series of Ammonium Monosubstituted H-Phosphonate Salts
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A series of ammonium monosubstituted H-phosphonate salts were synthesized by combining H-phosphonate diesters with amines in the absence of solvent at 80 °C. Variation of the ester substituent and amine produced a range of ionic liquids with low melting points. The products and by-products were analyzed by spectroscopic and spectrometric techniques in order to get a better mechanistic picture of the dealkylation and formal dearylation observed. For dialkyl H-phosphonate diesters, (RO)2P(O)H (R=alkyl), the reaction proceeds via direct dealkylation with the reactivity increasing in the order R=iPr?1. For the diphenyl H-phosphonate diesters, (PhO)2P(O)H, the dearylation was found to proceed via phenol-assisted formation of a 5-coordinate intermediate, (PhO)3PH(OH), from which P(OPh)3 and water were eliminated. The presence of an equivalent of water then facilitated the formation of P(OH)2OPh and the amine, R'NH2, subsequently abstracted a proton from it to yield [(PhO)PH(O)O]-[R'NH3]+.
- Lee, Keng Lung,Feld, Joey,Hume, Paul,S?hnel, Tilo,Leitao, Erin
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- Substituent effects on the 31P NMR chemical shifts of arylphosphorothionates
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Six tris(aryloxy)phosphorothionates substituted in the para position of the aromatic rings were synthesized and studied by 31P NMR, X-ray diffraction techniques and ab initio calculations at a RHF/6-31G** level of theory, in order to find the main structural factors associated with the δ31P in these compounds. As the electron-withdrawing (EW) ability of the substituents was increased, an 'abnormal' shielding effect on δ31P of the arylphosphorothionates was observed. The analyses of the geometrical properties obtained through both experimental and theoretical methods showed that a propeller-type conformation is preferred for the arylphosphorothionates, except in the case of the tris(O-4-methylphenyl) phosphorothionate, since one of the aromatic rings is not rotated in the same direction as the other two in the solid state. The main features associated with the δ31P NMR of compounds 1-6 were a decrease of the averaged O-P-O angle and mainly the shortening of the PS bond length, which is consistent with an increase of the thiophosphoryl bond order as δ31P values go upfield. On the other hand, comparison of the experimental and calculated bond lengths and bond angles involving α bonded atoms to phosphorus of the six compounds suggested that stereoelectronic interactions of the type nπO-σ*PS, nπO- σ*P-OAr and nπS-σ* P-OAr could be present in the arylphosphorothionates 1-6.
- Hernández, Javier,Goycoolea, Francisco M.,Zepeda-Rivera, Denisse,Juárez-Onofre, Josué,Martínez, Karla,Lizardi, Jaime,Salas-Reyes, Magali,Gordillo, Bárbara,Velázquez-Contreras, Carlos,García-Barradas, Oscar,Cruz-Sánchez, Samuel,Domínguez, Zaira
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- ELECTROCHEMICALLY INDUCED PROCESSES OF FORMATION OF PHOSPHORUS ACID DERIVATIVES. 4. SYNTHESIS OF TRIALKYL PHOSPHATES FROM WHITE PHOSPHORUS
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The products of electrolysis in dipolar aprotic solvents on the background of tetraethylammonium iodide in the presence of white phosphorus are trialkyl phosphite (the primary product after splitting of all the P - P bonds in the phosphoric oligomers) and triaryl phosphate.It was found that the formation of triaryl phosphate from white phosphorus proceeds by way of electrochemical reduction of pentaaroxyphosphorane - an intermediate product of the reaction of triaryl phosphite with iodine and phenol.A strong dependence of the yields and distribution of the products on the composition of the electrolyte has been observed. Keywords: white phosphorus, electrosynthesis, triaryl phosphate.
- Budnikova, Yu. G.,Kargin, Yu. M.,Zaripov, I. M.,Romakhin, A. S.,Ignat'ev, Yu. A.,et al.
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- A novel mild deprotection method for phosphine-boranes
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Treatment of phosphine-boranes with molecular sieves 4A in a mixture of an ethereal solvent and an alcohol provided deprotected free phosphines in quantitative yields. The phosphines can be obtained by a simple filtration/crystallization procedure in most cases. It should be noted that the current method is successfully applied to the deprotection of a phosphite-borane for the first time.
- Schroeder, Marc,Nozaki, Kyoko,Hiyama, Tamejiro
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- Diphenyl Diselenide-Catalyzed Synthesis of Triaryl Phosphites and Triaryl Phosphates from White Phosphorus
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Industrially important triaryl phosphites, traditionally prepared from PCl3, have been synthesized by a diphenyl diselenide-catalyzed one-step procedure involving white phosphorus and phenols, which provides a halogen- and transition metal-free way to these compounds. Subsequent oxidation of triaryl phosphites produces triaryl phosphates and triaryl thiophosphates. Phosphorotrithioates are also prepared efficiently from aromatic thiols and aliphatic thiols.
- Zhang, Yue,Cai, Ziman,Chi, Yangyang,Zeng, Xiangzhe,Chen, Shuanghui,Liu, Yan,Tang, Guo,Zhao, Yufen
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supporting information
p. 5158 - 5163
(2021/07/20)
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- Method for preparing phosphate ester derivatives from white phosphorus
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A method for preparing phosphate ester derivatives from white phosphorus relates to the field of chemical engineering, and comprises the following steps: adding alkali, a catalyst, a white phosphorus solution, ROH or RSH (R represents alkyl or aromatic group) into a reaction container in an inert atmosphere, and heating and stirring the mixture in a mixed solvent of toluene and DMSO (dimethyl sulfoxide) to react for a certain time, so as to obtain three-coordinated phosphate ester derivatives; and 2) continuing to add H2O2, air or sulfur powder until the oxidation is completed, thereby obtaining the tetra-coordinated phosphate ester derivative. According to the method, chlorine, phosphorus trichloride and halogen are not needed, phosphite ester is directly prepared from elementary white phosphorus in an efficient, green and environment-friendly manner, and phosphate and thiophosphate can be directly prepared after oxidation. High pollution and high corrosivity of a traditional method are avoided in the whole process; meanwhile, white phosphorus is completely converted in the whole process, white phosphorus residues are avoided, and the post-reaction treatment process is safe.
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Paragraph 0035-0052
(2021/06/23)
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- Phosphonic Analogs of Alanine as Acylpeptide Hydrolase Inhibitors
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Acylpeptide hydrolase is a serine protease, which, together with prolyl oligopeptidase, dipeptidyl peptidase IV and oligopeptidase B, belongs to the prolyl oligopeptidase family. Its primary function is associated with the removal of N-acetylated amino acid residues from proteins and peptides. Although the N-acylation occurs in 50–90 % of eukaryotic proteins, the precise functions of this modification remains unclear. Recent findings have indicated that acylpeptide hydrolase participates in various events including oxidized proteins degradation, amyloid β-peptide cleavage, and response to DNA damage. Considering the protein degradation cycle cross-talk between acylpeptide hydrolase and proteasome, inhibition of the first enzyme resulted in down-regulation of the ubiquitin-proteasome system and induction of cancer cell apoptosis. Acylpeptide hydrolase has been proposed as an interesting target for the development of new potential anticancer agents. Here, we present the synthesis of simple derivatives of (1-aminoethyl)phosphonic acid diaryl esters, phosphonic analogs of alanine diversified at the N-terminus and ester rings, as inhibitors of acylpeptide hydrolase and discuss the ability of the title compounds to induce apoptosis of U937 and MV-4-11 tumor cell lines.
- Walczak, Maciej,Chryplewicz, Agnieszka,Olewińska, Sandra,Psurski, Mateusz,Winiarski, ?ukasz,Torzyk, Karolina,Oleksyszyn, Józef,Sieńczyk, Marcin
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- Flash production of organophosphorus compounds in flow
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Flow synthesis techniques have received a significant amount of attention due to their high productivity. However, when reaction condition is heterogeneous, it is usually difficult to adapt it to flow synthesis. Herein, by selecting appropriate reagents, the synthesis of phosphate esters, which is commonly heterogeneous, was made homogeneous, enabling synthesis in flow systems. In addition, reaction rate was accelerated compared to the batch system. It was demonstrated that not only can the high productivity of flow synthesis be achieved in flow, but also high productivity can be achieved by accelerating the reaction. Finally, we demonstrated the synthesis of the Akiyama-Terada catalyst, a chiral organocatalysts, in a short period.
- Nagaki, Aiichiro,Tamaki, Takashi
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supporting information
(2021/09/09)
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- A Lewis Base Nucleofugality Parameter, NFB, and Its Application in an Analysis of MIDA-Boronate Hydrolysis Kinetics
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The kinetics of quinuclidine displacement of BH3 from a wide range of Lewis base borane adducts have been measured. Parameterization of these rates has enabled the development of a nucleofugality scale (NFB), shown to quantify and predict the leaving group ability of a range of other Lewis bases. Additivity observed across a number of series R′3-nRnX (X = P, N; R′ = aryl, alkyl) has allowed the formulation of related substituent parameters (nfPB, nfAB), providing a means of calculating NFB values for a range of Lewis bases that extends far beyond those experimentally derived. The utility of the nucleofugality parameter is explored by the correlation of the substituent parameter nfPB with the hydrolyses rates of a series of alkyl and aryl MIDA boronates under neutral conditions. This has allowed the identification of MIDA boronates with heteroatoms proximal to the reacting center, showing unusual kinetic lability or stability to hydrolysis.
- García-Domínguez, Andrés,Gonzalez, Jorge A.,Leach, Andrew G.,Lloyd-Jones, Guy C.,Nichol, Gary S.,Taylor, Nicholas P.
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supporting information
(2022/01/04)
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- Structure-based design, synthesis, and evaluation of the biological activity of novel phosphoroorganic small molecule IAP antagonists
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One of the strategies employed by novel anticancer therapies is to put the process of apoptosis back on track by blocking the interaction between inhibitor of apoptosis proteins (IAPs) and caspases. The activity of caspases is modulated by the caspases themselves in a caspase/procaspase proteolytic cascade and by their interaction with IAPs. Caspases can be released from the inhibitory influence of IAPs by proapoptotic proteins such as secondary mitochondrial activator of caspases (Smac) that share an IAP binding motif (IBM). The main purpose of the present study was the design and synthesis of phosphorus-based peptidyl antagonists of IAPs that mimic the endogenous Smac protein, which blocks the interaction between IAPs and caspases. Based on the structure of the IAP antagonist and recently reported thiadiazole derivatives, we designed and evaluated the biochemical properties of a series of phosphonic peptides bearing the N-Me-Ala-Val/Chg-Pro-OH motif (Chg: cyclohexylglycine). The ability of the obtained compounds to interact with the binding groove of the X-linked inhibitor of apoptosis protein baculovirus inhibitor of apoptosis protein repeat (XIAP BIR3) domain was examined by a fluorescence polarization assay, while their potential to induce autoubiquitination followed by proteasomal degradation of cellular IAP1 was examined using the MDA-MB-231 breast cancer cell line. The highest potency against BIR3 was observed among peptides containing C-terminal phosphonic phenylalanine analogs, which displayed nanomolar Ki values. Their antiproliferative potential as well as their proapoptotic action, manifested by an increase in caspase-3 activity, was examined using various cell lines.
- ?upicka-S?owik, Agnieszka,Psurski, Mateusz,Grzywa, Renata,Cuprych, Monika,Ciekot, Jaros?aw,Goldeman, Waldemar,Wojaczyńska, El?bieta,Wojaczyński, Jacek,Oleksyszyn, Józef,Sieńczyk, Marcin
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p. 1350 - 1364
(2020/04/24)
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- Palladium-catalyzed solvent-free preparation of arylphosphonates Arp(O)(OAr)2 from (Aro)3p via the Michaelis-Arbuzov rearrangement
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The Pd-catalyzed Michaelis-Arbuzov rearrangement of triaryl phosphites to produce the corresponding arylphosphonates in good to excellent yields is disclosed. In comparison to the traditional methods, this new method is highly atom efficient and is general, as it can be readily extended to aryl phosphonites and phosphinites. A gram-scale reaction of (PhO)3P to PhP(O)(OPh)2 with low loading of the catalyst was also demonstrated to show its potentially practical usefulness. A plausible mechanism is proposed.
- Li, Chunya,Han, Li-Biao
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supporting information
p. 3613 - 3617
(2020/11/03)
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- Preparation method of liquid phosphite antioxidant
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The invention relates to a preparation method of liquid phosphite antioxidant. The preparation method includes the steps of firstly, allowing phenol and phosphorus trichloride to have substitution reaction in the presence of catalyst to generate intermediate triphenyl phosphite, wherein the catalyst is amine or amidine with steric hindrance; secondly, allowing the generated intermediate triphenyl phosphite to have transesterification with isooctanol, and distilling and purifying to obtain the liquid diisooctyl phenyl phosphite. The preparation method has the advantages that the preparation method is mild in reaction condition, high in preparation safety coefficient, environmentally friendly, short in reaction cycle and high in product yield, does not need solvents and does not generate waste water and solid wastes, the reaction process can be controlled easily, raw materials can be recycled, and the prepared diisooctyl phenyl phosphite is high in content, low in acid value, clear and transparent in appearance, good in flowability, especially suitable for industrial production, and the like.
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Paragraph 0019; 0020
(2017/09/08)
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- A reaction distillation coupling preparation process of phosphorous acid ester compound
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The invention relates to a method for synthesizing phosphite ester compounds through esterification. Generally, phosphorus halide and alcohol or phenol are adopted for reaction. Taking monohydric alcohol as an example, the reaction equation is as follows: PCl3+3R-OH->P-(O-R)3+3HCl, wherein R is organic group, such as alkane, cycloparaffin, arene and the like. The equipment for the method comprises a reaction kettle, a tower, a circulating pump, a mixer, a heat exchanger and the like. The method has the beneficial effects that HCl generated by reaction is removed timely through the action of reactive rectification coupling, so that the reaction speed is greatly improved, ammonia hydrochloride or amine hydrochloride is prevented from generating due to addition of acid-binding agent, and the production cost of the existing technology is greatly lowered.
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Paragraph 0045; 0046
(2017/03/17)
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- Synthesis of fluorescent (benzyloxycarbonylamino)(aryl)methylphosphonates
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The synthesis of a library of structurally variable aromatic esters of (benzyloxycarbonylamino)(aryl)methylphosphonic acids is described by means of the Oleksyszyn reaction. The library was enlarged by the application of a Suzuki-Miayra approach and by preparation of mixed esters.
- Vel Gorniak, Michal Gorny,Czernicka, Anna,Mlynarz, Piotr,Balcerzak, Waldemar,Kafarski, Pawel
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supporting information
p. 741 - 745
(2014/05/06)
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- Human neutrophil elastase phosphonic inhibitors with improved potency of action
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Herein, we present the synthesis and the measurement of the inhibitory activity of novel peptidyl derivatives of α-aminoalkylphosphonate diaryl esters as human neutrophil elastase inhibitors. Their selectivity against other serine proteases, including porcine pancreatic elastase, chymotrypsin, and trypsin, was also demonstrated. We also describe the preparation of single peptide diastereomers. The most active and selective compound developed possessed a kinact/KI of 2353000 M-1 s -1, which is the most potent irreversible peptidyl inhibitor of human neutrophil elastase reported to date. The peptidyl inhibitors were demonstrated to be stable in PBS buffer and human plasma, as were their complexes with HNE.
- Winiarski, ?ukasz,Oleksyszyn, Józef,Sieńczyk, Marcin
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experimental part
p. 6541 - 6553
(2012/09/21)
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- Simple phosphonic inhibitors of human neutrophil elastase
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Herein, we describe the synthesis and resulting activity of a complex series of α-aminophosphonate diaryl esters as irreversible human neutrophil elastase inhibitors and their selectivity preference for human neutrophil elastase over several other serine proteases such as porcine pancreatic elastase, trypsin, and chymotrypsin. We synthesized and examined the inhibitory potency of several new simple Cbz-protected α- aminoalkylphosphonate diaryl esters that yielded several new HNE inhibitors, where one of the obtained compounds Cbz-ValP(OC6H 4-4-COOMe)2 displayed an apparent second-order inhibition value at 33,015 M-1 s-1.
- Sieńczyk, Marcin,Winiarski, ?ukasz,Kasperkiewicz, Paulina,Psurski, Mateusz,Wietrzyk, Joanna,Oleksyszyn, Józef
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supporting information; experimental part
p. 1310 - 1314
(2011/04/16)
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- New aromatic monoesters of α-aminoaralkylphosphonic acids as inhibitors of aminopeptidase N/CD13
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A series of new aromatic monoesters of α-aminoaralkylphosphonic acids were synthesized by selective hydrolysis of corresponding aromatic diesters of α-aminoaralkylphosphonic acids. New potential inhibitors of aminopeptidase N/CD13, an enzyme important in tumour angiogenesis, were developed. Some derivatives of the homophenylalanine and norleucine related monoaryl phosphonates displayed higher inhibition potency than corresponding α-aminoaralkylphosphonic acids toward aminopeptidase N/CD13. The effect of one of the new inhibitors on the growth of human PANC-1 and HT-1080 cell lines was examined, either alone or in combination with TNF-α.
- Grzywa, Renata,Sokol, Anna M.,Sieńczyk, Marcin,Radziszewicz, Magdalena,Ko?cio?ek, Beata,Carty, Michael P.,Oleksyszyn, Józef
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experimental part
p. 2930 - 2936
(2010/07/04)
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- Substituent effects on 31P NMR chemical shifts and 1J P-Se of triarylselenophosphates
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The effect of electron-withdrawing (EW) and electron-releasing (ER) substituents on the 31P NMR chemical shifts and the structural parameters of a series of tris-(p-X-aryl)selenophosphates is reported in this article. Similarly to O-aryl phosphates and O-aryl thiophosphates, EW groups attached to aromatic rings induce a shielding effect on the 31P NMR signal. After a detailed experimental and theoretical analysis, we confirmed that the selenium atom is the main part responsible for the charge density transfer toward phosphorus through a back-bonding effect. The obtained 1JP-Se values for the complete series agree with this observation. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.
- Dominguez, Zaira,Hernandez, Javier,Silva-Gutierrez, Lorena,Salas-Reyes, Magali,Sanchez, Mario,Merino, Gabriel
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experimental part
p. 772 - 784
(2010/07/05)
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- COUMESTAN-LIKE ANTIOXIDANTS AND UV ABSORBANTS
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The present invention relates to derivatives of the 1H-pyrano[4,3-b]benzofuran-1-one structure and their nitrogen analogues which possess powerful antioxidant properties combined with a highly effective UV absorbing functionality in one molecule. These compounds are especially useful in cosmetical and dermatological formulations.
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- DIARYL ALKYLPHOSPHONATES AND METHODS FOR PREPARING SAME
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A method of making optionally substituted diaryl alkylphosphonates from an optionally substituted arylol, an optionally substituted alkanol, and a phosphorous trihalide is described.
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Page/Page column 6
(2008/06/13)
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- Inhibition of trypsin and urokinase by Cbz-amino(4-guanidinophenyl)methanephosphonate aromatic ester derivatives: The influence of the ester group on their biological activity
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The urokinase plasminogen activator is a trypsin-like serine protease, important in tumor development. Here, we report the synthesis and biochemical evaluation of selective and potent diaryl esters of phosphonic-type inhibitors for urokinase. We have found that the substituted phenyl ester ring has a strong influence on the inhibitory activity of these compounds. This led to the most potent phosphonic inhibitor for uPA synthesized to date.
- Sieńczyk, Marcin,Oleksyszyn, Józef
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p. 2886 - 2890
(2008/09/20)
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- Dismutation of arylene phosphorodiamidites: Specific features and aspects of preparative use
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The dismutation of arylene phosphorodiamidites derived from the simplest phenols and naphthols and of their dibasic analogs was studied. The main regular trends of this process and the limits of its synthetic applicability were determined. Pleiades Publishing, Inc., 2006.
- Rasadkina,Slitikov,Nifant'ev
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p. 183 - 197
(2008/02/08)
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- Work-up-free deprotection of borane complexes of phosphines, phosphites, and phosphinites with polymer-supported amines
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Borane complexes of phosphorus compounds, a very common oxidation-free relay for catalytic ligands (phosphines, phosphites, and phosphinites), can be easily deprotected by treatment with polymer-supported piperazine or N-methylpiperazine. Deprotection conditions have been optimized for the different types of phosphorus compounds, and the resulting solutions can be used without any intermediate work-up or purification process. Georg Thieme Verlag Stuttgart.
- Sayalero, Sonia,Pericàs, Miquel A.
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p. 2585 - 2588
(2008/09/16)
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- Hydroxy-substituted N-alkoxy hindered amines and compositions stabilized therewith
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Hindered amines substituted on the N-atom with an hydroxy-substituted alkoxy moiety are particularly effective in stabilizing organic polymer compositions against the deleterious effects of oxidative, thermal and actinic radiation where the presence of the OH group on the compounds adds important properties not otherwise attainable.
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- Substituted 5-heteroaryl-2-(2-hydroxyphenyl)-2h-benzotriazole UV absorbers, a process for preparation thereof and compositions stabilized therewith
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Compounds of formula I or II where R is a heteroaryl moiety, such as 3-pyridyl, or T is a heteroaryl moiety, such as thien-2,5-diyl, and E1and E2are independently hydrogen, alkyl, aralkyl and the like, are prepared by reaction of a benzotriazole substituted on the 5-position of the benzo ring by a halogen atom with a heteroarylboronic acid or ester in the presence of a transition-metal catalyst, such as palladium (II) diacetate. The benzotriazole compounds of formula I are particularly efficacious as stabilizers for automotive coatings and candle wax.
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- Aryl H-phosphonates. 7. Studies on the formation of phosphorus-carbon bond in the reaction of trityl and benzyl halides with dialkyl and diphenyl H-phosphonates
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The reactions of H-phosphonate diesters with trityl and benzyl halides were investigated using 31P NMR spectroscopy. It was found that extensive oxidation, which usually accompanies the formation of trityl- or p-nitrobenzylphosphonates from the corresponding alkyl bromides in the Michaelis-Becker reaction, can be considerably suppressed or completely eliminated by reacting p-nitrobenzyl or trityl bromides with diphenyl H-phosphonate in acetonitrile in the presence of DBU.
- Kers, Annika,Stawinski, Jacek,Dembkowski, Leszek,Kraszewski, Adam
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p. 12691 - 12698
(2007/10/03)
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- Phosphane, phosphite, phosphido complexes of vanadium(V)
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Complex formation of tert-butylimidovanadium(V)trichloride (1) with phosphanes und phosphites has been studied. Syntheses of phosphidovanadium(V) compounds tC4H9N=VCp(NHtC4H 9)[P(SiMe3)2] and tC4H9N=VCp(NiProp 2)(PR2) (R = SiMe3, Ph) are described starting from the corresponding chlorovanadium(V) complexes. The reaction of 1 with silver hexafluorophosphate yields a bis(fluoro)phosphidovanadium(IV) complex [(μ-PF2)2V2Cl2(N tC4H9)2]; as primary intermediate product of the unknown redox reaction a cationic vanadium(V) complex [tC4H9N=VCl2 · PPh3]+PF6- has been isolated. 1 reacts with an excess of diisopropylamine forming tC4H9N=V(NiProp2)Cl 2 (16); in addition the following diisopropylamido-tert-butylimidovanadium(V) compounds tC4H9N=VCp(NiProp2)Cl (3) and tC4H9N=V(NiProp2)X 2 (X = CH2CMe3, OtC4H9, CH3COO) has been prepared. All compounds obtained are characterized by 1H, 51V, 31P NMR spectroscopy. The X-ray diffraction analysis of 16 and 3 indicate a planar coordination sphere of the amido nitrogen atom.
- Preuss,Steidel,Vogel,Overhoff,Hornung,Towae,Frank,Reiss,Mueller-Becker
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p. 1220 - 1228
(2008/10/09)
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- Studies on aryl H-phosphonates. 3. Mechanistic investigations related to the disproportionation of diphenyl H-phosphonate under anhydrous basic conditions
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Diphenyl H-phosphonate undergoes under anhydrous reaction conditions a base-promoted disproportionation to triphenyl phosphite and phenyl H- phosphonate. On the basis of 31P NMR data the most likely mechanism for this transformation was proposed. In order to substantiate these findings and to get a deeper insight into the chemistry of aryl H-phosphonate esters, we carried out also some studies on activation of phenyl and diphenyl H- phosphonates with various condensing agents. We found that aryl vs alkyl esters of phosphonic acid often follow different reaction pathways during the activation, and this can most likely be traced back to higher electrophilicity of the phosphorus centre and to higher reactivity of the P- H bonds in aryl H-phosphonate derivatives.
- Kers, Annika,Kers, Inger,Stawinski, Jacek,Sobkowski, Michal,Kraszewski, Adam
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p. 9931 - 9944
(2007/10/03)
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- Use of ammonium aryl H-phosphonates in the preparation of nucleoside H-phosphonate building blocks
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Ammonium 4-methylphenyl H-phosphonate 4c was used in the conversion of 5'-0-(dimethoxy-trityl)-2'-deoxynucleoside derivatives 6 into the corresponding 3'-H-phosphonates 2, which were isolated in a high state of purity and in high yield.
- Ozola, Vita,Reese, Colin B.,Song, Quanlai
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p. 8621 - 8624
(2007/10/03)
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- REACTIONS OF 2-DIETHYLAMINO-5-METHYL-1,3,2-OXATHIAPHOSPHOLENE WITH PROTON-DONOR REAGENTS AND CHLOROPHOSPHINES
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The ethanolysis ond phenolysis of 2-diethylamino-5-methyl-1,3,2-oxathiaphospholene were studied.In the first case we observe the initial splitting of the endocyclic P-E bonds, and in the second case the replacement of the dialkylamino group by the phenoxy group, with the cyclic fragment retained.Similarly to the phenolysis, the phospholene reacts with hydrogen chloride and carboxylic acids. 2-Dialkylamino(alkoxy)-1,3,2-oxathiaphospholenes undergo exchange reactions with P(III) chlorides on heating.
- Burilov, A.R.,Nikolaeva, I.L.,Pudovik, M.A.
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p. 685 - 687
(2007/10/02)
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- Syntheses und NMR-Spektren phosphororganischer Antioxidantien und verwandter Verbindungen
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The syntheses of various aliphatic, aromatic, sterically hindered, and cyclic organophosphorus compounds (phosphorous acid esters, esters chlorides and ester amides, hydrogen phosphites, phosphinates and phosphates) are reported, and general procedures for preparation are given.The compounds synthesized were investigated by means of 31P-, 1H- and 13C-n.m.r. spectroscopy, and the chemical shifts measured are listed.
- Koenig, T.,Habicher, W.D.,Haehner, U.,Pionteck, J.,Rueger, C.,Schwetlick, K.
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p. 333 - 349
(2007/10/02)
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- SYNTHESIS OF SYMMETRICAL AND UNSYMMETRICAL TRIESTER PHOSPHITES
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A method for one-pot synthesis of either symmetrical or unsymmetrical triester phosphites 1O)2P, (RO)(R1O)(R2O)P, and ROPOO(CH2)n; R, R1, R2 = alkyl or phenyl> at room temperature is proposed.Hexaalkyltriamides of phosphorus acid and amidophosphite intermediates 1O)PNR*2; R* = CH3, C2H5>, activated by imidazole and carbondisulfide, are used as new phosphorylating reagents.Six phosphite and thiophosphate triester derivatives of phenol, cis-9-octadecene-1ol, cholesterol, β-sitisterol, 1,3-butane diol and 1-nonanol have been synthesized in high final yields (85-94percent).Key words: Triester phosphites; amidophosphites; reagent; phosphorylation; thiophosphates; activation.
- Stamatov, Stephan D.,Ivanov, Stephan A.
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- Organophosphorus Antioxidants. X. The Hydroperoxide Decomposing Action of Phosphites, Phosphonites and Thiophosphites
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The kinetics and mechanism of reactions of phosphites, phosphonites, thiophosphites and hydrogenphosphites with cumyl (CHP), t-butyl (TBHP) and α-tetralyl (THP) hydrogenperoxides has been studied by means of (31)P-n.m.r. spectroscopy, high performance liquid chromatography and iodometric titration.All three valent phosphorus compounds studied initially react with hydroperoxides stoichiometrically to give the corresponding P=O products and alcohol.Some species are able to decompose cumyl hydroperoxide catalytically to form phenol and aceton.Acyloin phosphites decompose CHP catalytically after a stoichiometric reaction as thiophosphites do.Tetramethylpiperidinyl phosphites ("HALS-phosphites") react with hydroperoxides only stoichiometrically but with high velocity.Phosphonites react with hydroperoxides in the same way as the corresponding phosphites.Their reactivity, however, is much higher.Hydrogenphosphites are less reactive than phosphites in the reaction with hydroperoxides.They are able to act catalytically.
- Koenig, T.,Habicher, W. D.,Schwetlick, K.
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p. 913 - 922
(2007/10/02)
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- Process for the hydroformylation of certain acrylic acid derivatives
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A process for the hydroformylation of a compound of general formula, , R1 - CH = wherein R1 represents a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms and R2 represents an alkyl group having from 1 to 18 carbon atoms, which comprises hydroformylating the compound of general formula I with carbon monoxide and hydrogen in the liquid phase in the presence of a homogeneous catalyst system comprising, a) a rhodium compound and b) one or more triphenylphosphites, the phenyl groups of which may optionally be substituted by halogen, alkyl having from 1 to 6 carbon atoms, alkoxy having from 1 to 6 carbon atoms, carboxy or cyano, at a temperature in the range of from 50 to 100°C and a pressure in the range of from 3 to below 100 bars.
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- Chewing insect toxicant compositions
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This invention relates to chewing insect toxicant compositions comprising (1) a 1-(mono-substituted phenyl)-3-benzoyl urea compound in admixture with (2) an amount sufficient to enhance the chewing insect toxicity of said urea compound of a phosphorous-containing compound. This invention is also directed to chewing insect toxicant compositions comprising an acceptable carrier and as the active toxicant an effective amount of the composition of this invention as well as to a method of controlling insects by subjecting them to an effective amount of the composition of this invention.
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- Quasiphosphonium Intermediates. Part 3. Preparation, Structure, and Reactivity of Alkoxyphosphonium Halides in the Reaction of Neopentyl Diphenylphosphinite, Dineopentyl Phenylphosphinite, and Trineopentyl Phosphite with Halogenomethanes and the Effect of Phenoxy-substituenst on the ...
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The reactions of neopenthyl diphenylphosphinite with chloro-, bromo-, or iodo-methane and of dineopentyl phenylphosphphonite with bromo- or iodo-methane yield crystalline alkoxyphosphonium halides.In deuteriochloroform these intermediates decompose by a first-order process which involves rate-determining collapse of the phosphonium halide ion-pair with SN2-type fission of the alkyl-oxygen bond.Rates for chloride, bromide, and iodide are similar.In a more ionising medium (deuterioacetonitrile) dissociation leads to stabilisation of the intermediates and to deviation from first-order decomposition.Previously determined X-ray diffraction data for the bromides, together with relative rates of decomposition in deuteriochloroform for intermediates in the series Phn(RO)3-nP+MeX- (n = 0,1, or 2) suggest that the stability and reactivity of alkoxyphosphonium intermediates are determined largely by inductive rather than mesomeric effects of ligands.The presence of phenoxy-substituents on phosphorus may cause a tendency towards SN1-type fission of the alkyl-oxygen bond in certain circumstances.
- Hudson, Harry R.,Kow, Aloysius,Roberts, John C.
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p. 1363 - 1368
(2007/10/02)
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- Process for the preparation of neutral phosphorous acid aryl esters
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A process for the preparation of a neutal phosphorous acid aryl ester of the general formula STR1 wherein a phosphorus trihalide, phosphorus acid monoester dihalide or phosphorous acid diester halide is reacted with a hydroxyaryl compound wherein an excess of hydroxyaryl compound and an excess of aqueous alkali metal hydroxide solution or suspension or alkaline earth metal hydroxide solution or suspension are employed, relative to the phosphorus halide compound, an inert water immiscible organic solvent and/or diluent is employed in an amount such that 5 to 50% strength solution of the neutral phosphorous acid aryl ester is formed and after the reaction, the organic phase is separated off and the phosphorous acid aryl ester formed is isolated by removing the solvent and/or diluent.
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- Method of purifying triaryl phosphites
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The subject matter of the invention is a method of preparing pure triaryl phosphites by treatment with a hydrogen compound of nitrogen. The invention can be applied to decolorizing triaryl phosphites with a view to using them as stabilizers, antioxidants and complex-forming agents in the plastics and rubber industries.
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