1571-33-1Relevant articles and documents
Kinetics and mechanisms of oxidations by metal ions. X. Oxidation of phosphinic and phenylphosphinic acids by tris(polypyridyl)iron(III) complexes
Sharma,Prakash,Mehrotra
, p. 4009 - 4015 (1989)
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Two step acidic hydrolysis of dialkyl arylphosphonates
Harsági, Nikoletta,Rádai, Zita,Kiss, Nóra Zsuzsa,Szigetvári, Aron,Keglevich, Gy?rgy
, p. 38 - 39 (2020)
The HCl-catalyzed hydrolysis of dialkyl arylphosphonates monitored by 31P NMR spectroscopy has revealed two consecutive steps characterized by pseudo first order rate constants k1 and k2. A reactivity order for the two steps and for the overall two step hydrolysis has been derived depending on the alkoxy and aryl substituents. Besides the AAc2 mechanism, the AAl1 route has been substantiated for the PriO substituent.
Kinetics and mechanism of the oxidation of lower oxyacids of phosphorus by hexamethylenetetramine bromine
Mehla, Satish K.,Kothari, Seema,Banerji, Kalyan K.
, p. 165 - 170 (2000)
The oxidation of lower oxyacids of phosphorus by hexamethylenetetramine bromine (HABR) in glacial acetic acid resulted in the formation of corresponding oxyacids with phosphorus in a higher oxidation state. The reaction exhibited 2:1 stoichiometry. The reaction is first order with respect to HABR. Michaelis-Menten-type kinetics were observed with respect to the acids. The formation constant of the phenylphosphinic acid-HABR complex also has been determined spectrophotometrically. The thermodynamic parameters for the complex formation and the activation parameters for their decomposition were calculated. The reaction showed the presence of a substantial kinetic isotope effect. It is proposed that the HABR itself is the reactive oxidizing species. It has been shown that the pentacoordinated tautomer of the phosphorus oxyacid is the reactive reductant. A suitable mechanism has been proposed.
Hydrolysis-Based Small-Molecule Hydrogen Selenide (H2Se) Donors for Intracellular H2Se Delivery
Bolton, Sarah G.,Chouinard, Julie E.,Garcia, Arman C.,Golledge, Stephen L.,Newton, Turner D.,Pluth, Michael D.,Zakharov, Lev N.
, p. 19542 - 19550 (2021/11/23)
Hydrogen selenide (H2Se) is a central metabolite in the biological processing of selenium for incorporation into selenoproteins, which play crucial antioxidant roles in biological systems. Despite being integral to proper physiological function, this reactive selenium species (RSeS) has received limited attention. We recently reported an early example of a H2Se donor (TDN1042) that exhibited slow, sustained release through hydrolysis. Here we expand that technology based on the P-Se motif to develop cyclic-PSe compounds with increased rates of hydrolysis and function through well-defined mechanisms as monitored by 31P and 77Se NMR spectroscopy. In addition, we report a colorimetric method based on the reaction of H2Se with NBD-Cl to generate NBD-SeH (λmax = 551 nm), which can be used to detect free H2Se. Furthermore, we use TOF-SIMS (time of flight secondary ion mass spectroscopy) to demonstrate that these H2Se donors are cell permeable and use this technique for spatial mapping of the intracellular Se content after H2Se delivery. Moreover, these H2Se donors reduce endogenous intracellular reactive oxygen species (ROS) levels. Taken together, this work expands the toolbox of H2Se donor technology and sets the stage for future work focused on the biological activity and beneficial applications of H2Se and related bioinorganic RSeS.
Wet and dry processes for the selective transformation of phosphonates to phosphonic acids catalyzed by br?nsted acids
Li, Chunya,Saga, Yuta,Onozawa, Shun-Ya,Kobayashi, Shu,Sato, Kazuhiko,Fukaya, Norihisa,Han, Li-Biao
supporting information, p. 14411 - 14419 (2020/12/29)
A "wet"process and two "dry"processes for converting phosphonate esters to phosphonic acids catalyzed by a Bronsted acid have been developed. Thus, in the presence of water, a range of alkyl-, alkenyl-, and aryl-substituted phosphonates can be generally hydrolyzed to the corresponding phosphonic acids in good yields catalyzed by trifluoromethyl sulfonic acid (TfOH) at 140 °C (the wet process). On the other hand, with specific substituents of the phosphonate esters, the conversion to the corresponding phosphonic acids can be achieved under milder conditions in the absence of water (the dry process). Thus, the conversion of dibenzyl phosphonates to the corresponding phosphonic acids took place smoothly at 80 °C in toluene or benzene in high yields. Moreover, selective conversion of benzyl phosphonates RP(O)(OR′)(OBn) to the corresponding mono phosphonic acids RP(O)(OR′)(OH) can also be achieved under the reaction conditions. The dealkylation via the generation of isobutene of ditert- butyl phosphonate, and the related catalysis by TfOH took place even at room temperature to give the corresponding phosphonic acids in good to high yields. Nafion also shows high catalytic activity for these reactions. By using Nafion as the catalyst, phosphonic acids could be easily prepared on a large scale via a simple process.
