1080-32-6Relevant academic research and scientific papers
2D Ultrafast HMBC 1H,31P: Obtaining mechanistic details on the Michaelis-Arbuzov reaction
Fernández-Valle, María Encarnación,Martínez-álvarez, Roberto,Molero-Vílchez, Dolores,Pardo, Zulay D.,Sáez-Barajas, Elena,Herrera, Antonio
, p. 799 - 805 (2015)
Ultrafast NMR spectroscopy (UF-NMR) can be used to monitor chemical reactions in real time and to provide insights into their mechanisms and the nature of the intermediates formed. Here, we have developed a 2D 1H,31P UF-HMBC method and the corresponding NMR experimental setup to enable the study of a Michaelis-Arbuzov reaction at two different temperatures, 25 and 70 °C. The specific reaction studied was between triethyl phosphite and benzyl bromide to produce diethylbenzyl phosphonate. Our results show that at 70 °C the reaction takes place directly, without the detection of an intermediate by 1H,31P UF-HMBC. In contrast, at 25 °C, using zinc bromide as a catalyst, our results show the formation of benzyltriethoxy phosphonium bromide as an intermediate. The experiments again show the power of UF-NMR in mechanistic studies of reactions involving various phosphorus chemical species.
Pseudodimeric Complexes of an (18-Crown-6)stilbene with Styryl Dyes Containing an Ammonioalkyl Group: Synthesis, Structure, and Stereospecific [2 + 2] Cross-Photocycloaddition
Martyanov, Timofey P.,Ushakov, Evgeny N.,Nuriev, Vyacheslav N.,Aleksandrova, Nadezhda A.,Sazonov, Sergey K.,Vedernikov, Artem I.,Kuz'mina, Lyudmila G.,Klimenko, Lubov S.,Martyanova, Elena G.,Gromov, Sergey P.
, p. 3164 - 3175 (2021)
A new efficient method was proposed for the synthesis of (18-crown-6)stilbene; the structure of the product was confirmed by X-ray diffraction analysis. In MeCN, this compound forms pseudodimeric complexes with N-(2-ammonioethyl)-4-styrylpyridinium and N-(3-ammoniopropyl)-4-styrylpyridinium diperchlorates via hydrogen bonding between the ammonium group and the crown ether oxygen atoms. The ammonioethyl derivative was synthesized for the first time. The stability constants and spectral characteristics of the complexes were measured by spectrophotometric and fluorescence titration. Photoirradiation of the pseudodimeric complex of (18-crown-6)stilbene with the ammoniopropyl dye resulted in the stereospecific [2 + 2] cross-photocycloaddition reaction. The replacement of the stilbene moiety in the crown compound by a styrylpyridine moiety led to a 5-fold increase in the quantum yield of the photoprocess. The most probable cause for this effect is the presence of photoinduced electron transfer in (18-crown-6)stilbene complexes. This assumption is confirmed by fluorescence lifetime spectroscopy and density functional theory calculations.
Lanthanoid-metal-mediated reaction of acylphosphonates: evidence for the formation of an acyllanthanoid complex
Taniguchi, Yuki,Fujii, Nobuto,Takaki, Ken,Fujiwara, Yuzo
, p. 173 - 180 (1995)
The reactions of diethyl acylphosphonates (1a-e) with Yb and Sm were examined.Reactivities of Yb to 1a-e are different from those of Li and Na.Typically, ethyl benzoylphosphonate (1a) reacts with Yb metal in tetrahydrofuran-hexamethylphosphoramide to afford diethyl 1,2-diphenyl-2-oxoethyl phosphate (2a) and diethyl 1-(diethyl-phosphoryloxy)-1-phenylmethylphosphonate (3a) The formations of 2a and 3a were explained best by the formation of acylytterbium complexes.Keywords: Ytterbium; Samarium; Acylphosphonate; Phosphorus
Crystal structures of the apo form and a complex of human LMW-PTP with a phosphonic acid provide new evidence of a secondary site potentially related to the anchorage of natural substrates
Fonseca, Emanuella M.B.,Trivella, Daniela B.B.,Scorsato, Valéria,Dias, Mariana P.,Bazzo, Natália L.,Mandapati, Kishore R.,De Oliveira, Fábio L.,Ferreira-Halder, Carmen V.,Pilli, Ronaldo A.,Miranda, Paulo C.M.L.,Aparicio, Ricardo
, p. 4462 - 4471 (2015)
Low molecular weight protein tyrosine phosphatases (LMW-PTP, EC 3.1.3.48) are a family of single-domain enzymes with molecular weight up to 18 kDa, expressed in different tissues and considered attractive pharmacological targets for cancer chemotherapy. Despite this, few LMW-PTP inhibitors have been described to date, and the structural information on LMW-PTP druggable binding sites is scarce. In this study, a small series of phosphonic acids were designed based on a new crystallographic structure of LMW-PTP complexed with benzylsulfonic acid, determined at 2.1 ?. In silico docking was used as a tool to interpret the structural and enzyme kinetics data, as well as to design new analogs. From the synthesized series, two compounds were found to act as competitive inhibitors, with inhibition constants of 0.124 and 0.047 mM. We also report the 2.4 ? structure of another complex in which LMW-PTP is bound to benzylphosphonic acid, and a structure of apo LMW-PTP determined at 2.3 ? resolution. Although no appreciable conformation changes were observed, in the latter structures, amino acid residues from an expression tag were found bound to a hydrophobic region at the protein surface. This regions is neighbored by positively charged residues, adjacent to the active site pocket, suggesting that this region might be not a mere artefact of crystal contacts but an indication of a possible anchoring region for the natural substrate - which is a phosphorylated protein.
Rapid and efficient Arbuzov reaction under microwave irradiation
Villemin, Didier,Simeon, Fabrice,Decreus, Hugues,Jaffres, Paul-Alain
, p. 209 - 213 (1998)
Diethyl alkylphosphonates are efficiently and rapidly prepared in good yields (75-99%) from trialkylphosphates and alkyl halides under short microwaves irradiations.
SIMPLE CONVERSION OF ARYL BROMIDES TO ARYLMETHYLPHOSPHONATES
Poindexter, Michael K.,Katz, Thomas J.
, p. 1513 - 1516 (1988)
Aryl bromides in tetrahydrofuran when combined with t-butyllithium and then with cuprous iodide and diethyl chloromethylphosphonate give diethyl arylmethylphosphonates.
The photoisomerization of: Cis, trans -1,2-dideuterio-1,4-diphenyl-1,3-butadiene in solution. No bicycle-pedal
Saltiel, Jack,Redwood, Christopher E.,Ratheesh Kumar
, p. 2174 - 2179 (2019)
cis,trans-1,2-Dideuterio-1,4-diphenyl-1,3-butadiene (ct-DPBd2) was synthesized and its cis-trans photoisomerization in cyclohexane-d12 (C6D12) at room temperature was monitored by 1H NMR spectroscopy. The results reveal formation of only trans,trans-1,2-dideuterio-1,4-diphenyl-1,3-butadiene (tt-DPBd2). The failure to detect formation of trans,cis-1,2-dideuterio-1,4-diphenyl-1,3-butadiene (tc-DPBd2) eliminates the possibility that an identity bicycle pedal process contributes to inefficiency in the cis-trans photoisomerization of cis,trans-1,4-diphenyl-1,3-butadiene (ct-DPB).
Palladium-catalyzed cross-coupling reactions of organocopper derivatives of methylphosphonic esters and amides with aryl and hetaryl iodides
Lukashev,Tarasenko,Beletskaya
, p. 172 - 178 (2001)
Copper derivatives of methylphosphonic amides are sufficiently stable thermally and can be used in palladium-catalyzed arylation reactions resulting in synthesis of previously unknown aryl- and hetaryl-methylphosphonic tetramethyldiamides in high yields.
Synthesis, UV/vis spectra and electrochemical characterisation of arylthio and styryl substituted ferrocenes
Sorensen, Thomas J.,Nielsen, Merete F.
, p. 610 - 618 (2011)
Two series of substituted ferrocenes were synthesised using either the Horner-Wadswor th-Emmons reaction or monolithiation of ferrocene. The series consist of arylthio- and styryl-ferrocenes with different substituents in the para position of the aryl rings of the systems. The electronic communication was investigated by comparing the substituent effects in absorption spectroscopy and in cyclic voltammetry. A small substituent effect was found in the electronic transitions of the styryl substituted ferrocenes. The oxidation of the ferrocene derivatives showed clear substituent effects as illustrated by the linear Hammett plots. The effect was shown to be an order of magnitude larger in the arylthio-systems than in the styryl systems. It is suggested that the reason behind the large effect is a direct sulfur-iron orbital overlap. Versita Sp. z o.o.
Acetic acid mediated synthesis of phosphonate-substituted titanium oxo clusters
Czakler, Matthias,Artner, Christine,Schubert, Ulrich
, p. 2038 - 2045 (2014)
New phosphonate/acetate-substituted titanium oxo/alkoxo clusters were prepared from Ti(OiPr)4 and bis(trimethylsilyl) phosphonates in the presence of acetic acid, which served to generate water in situ through ester formation. The process led to clusters with a higher degree of condensation than in previously known phosphonate-substituted titanium oxo clusters. The clusters [Ti6O4(OiPr)10(OAc)2(O 3PR)2] (OAc = acetate) were obtained for a large variety of functional and non-functional groups R under a range of reaction conditions. This cluster type, which is also retained in solution, therefore appears to be very robust. Two other clusters, [Ti5O(OiPr)11(OAc)(O 3PCH2CH2CH2Br)3] and [Ti5O3(OiPr)6(OAc)4(O 3P-xylyl)2], were only isolated in special cases. Several acetate/phosphonate-substituted titanium cage compounds were obtained from the reaction of titanium isopropoxide with bis(trimethylsilyl) phosphonates in the presence of acetic acid as water generator.
