1118-85-0Relevant academic research and scientific papers
Manganese Porphyrin Catalyzed Homogeneous Aqueous Oxidation of Organic Molecules by Magnesium Monoperoxyphthalate (MMPP)
Zheng, Tu-Cai,Richardson, David E.
, p. 837 - 840 (1995)
Magnesium monoperoxyphthalate (MMPP) oxidizes a variety of organic molecules in neutral homogeneous aqueous solutions at room temperature.A water-soluble porphyrin complex, meso-tetrakis-(4-N-methylpyridyl)porhyrinatomanganese(III) chloride, Mn(III)TMPyP(4) Cl, acts as an efficient catalyst for the epoxidation and hydroxylation of water-soluble hydrocarbons.
“Dark” Singlet Oxygen Made Easy
Elsherbini, Mohamed,Allemann, Rudolf K.,Wirth, Thomas
, p. 12486 - 12490 (2019)
An operationally simple continuous flow generator of “dark” singlet oxygen has been developed. The singlet oxygen was efficiently reacted with several chemical traps to give the corresponding oxygenated products in high yields. The developed “dark” singlet oxygen generator has been successfully applied in the synthesis of the antimalarial drug artemisinin.
Direct monitoring of biocatalytic deacetylation of amino acid substrates by1H NMR reveals fine details of substrate specificity
De Cesare, Silvia,McKenna, Catherine A.,Mulholland, Nicholas,Murray, Lorna,Bella, Juraj,Campopiano, Dominic J.
, p. 4904 - 4909 (2021)
Amino acids are key synthetic building blocks that can be prepared in an enantiopure form by biocatalytic methods. We show that thel-selective ornithine deacetylase ArgE catalyses hydrolysis of a wide-range ofN-acyl-amino acid substrates. This activity was revealed by1H NMR spectroscopy that monitored the appearance of the well resolved signal of the acetate product. Furthermore, the assay was used to probe the subtle structural selectivity of the biocatalyst using a substrate that could adopt different rotameric conformations.
Reactive ZrIV and HfIV butterfly peroxides on polyoxometalate surfaces: Bridging the gap between homogeneous and heterogeneous catalysis
Carraro, Mauro,Nsouli, Nadeen,Oelrich, Holger,Sartorel, Andrea,Soraru, Antonio,Mal, Sib Sankar,Scorrano, Gianfranco,Walder, Lorenz,Kortz, Ulrich,Bonchio, Marcella
, p. 8371 - 8378 (2011)
At variance with previously known coordination compounds, the polyoxometalate (POM)-embedded ZrIV and HfIV peroxides with formula: [M2(O2)2(α-XW 11O39)2]12- (M=ZrIV, X=Si (1), Ge (2); M=HfIV, X=Si (3)) and [M6(O 2)6(OH)6(γ-SiW10O 36)3]18- (M=ZrIV (4) or Hf IV (5)) are capable of oxygen transfer to suitable acceptors including sulfides and sulfoxides in water. Combined 1HNMR and electrochemical studies allow monitoring of the reaction under both stoichiometric and catalytic conditions. The reactivity of peroxo-POMs 1-5 is compared on the basis of substrate conversion and kinetic. The results show that the reactivity of POMs 1-3 outperforms that of the trimeric derivatives 4 and 5 by two orders of magnitude. Reversible peroxidation of 1-3 occurs by H 2O2 addition to the spent catalysts, restoring oxidation rates and performance of the pristine system. The stability of 1-3 under catalytic regime has been confirmed by FT-IR, UV/Vis, and resonance Raman spectroscopy. The reaction scope has been extended to alcohols, leading to the corresponding carbonyl compounds with yields up to 99 % under microwave (MW) irradiation. DFT calculations revealed that polyanions 1-3 have high-energy peroxo HOMOs, and a remarkable electron density localized on the peroxo sites as indicated by the calculated map of the electrostatic potential (MEP). This evidence suggests that the overall description of the oxygen-transfer mechanism should include possible protonation equilibria in water, favored for peroxo-POMs 1-3. Copyright
Peroxo-Cerium(IV)-Containing Polyoxometalates: [CeIV6(O2)9(GeW10O37)3]24-, a Recyclable Homogeneous Oxidation Catalyst
Qasim, Hafiz M.,Ayass, Wassim W.,Donfack, Patrice,Mougharbel, Ali S.,Bhattacharya, Saurav,Nisar, Talha,Balster, Torsten,Solé-Daura, Albert,R?mer, Isabella,Goura, Joydeb,Materny, Arnulf,Wagner, Veit,Poblet, Josep M.,Bassil, Bassem S.,Kortz, Ulrich
, p. 11300 - 11307 (2019)
The class of peroxo-cerium-containing polyoxometalates has been discovered via the synthesis of the 9-peroxo-6-cerium(IV)-containing 30-tungsto-3-germanate, [CeIV6(O2)9(GeW10O37)3]24- (1). Polyanion 1 consists of a cyclic [Ce6(O2)9]6+ assembly that is stabilized by three dilacunary [GeW10O37]10- Keggin fragments. The title polyanion 1 is solution-stable, on the basis of 183W nuclear magnetic resonance, and was shown to act as a recyclable homogeneous catalyst for the selective, microwave-activated sulfoxidation of the model substrate methionine to the sulfoxide in the absence and to the sulfone in the presence of hydrogen peroxide. Solution and solid-state Raman as well as solid-state infrared studies of 1 demonstrated the complete loss (and regain) of the nine peroxo groups in situ during the catalytic cycle, suggesting that the peroxo-free {Ce6(GeW10)3} skeleton remains most likely intact during the catalytic cycle. Solid-state X-ray photoelectron spectroscopy measurements showed that peroxo loss is accompanied by reduction of the cerium ions from +4 to +3, which is fully reversible. Density functional theory calculations are in complete agreement with all of these observations and furthermore suggest that the reduction of the six cerium(IV) ions is accompanied by the formation of molecular dioxygen.
A Donor-Acceptor [2]Catenane for Visible Light Photocatalysis
?or?evi?, Luka,Cai, Kang,Chen, Hongliang,Chen, Xiao-Yang,Feng, Yuanning,Jaynes, Tyler,Jiao, Yang,Mao, Haochuan,Qiu, Yunyan,Stoddart, J. Fraser,Stupp, Samuel I.,Wasielewski, Michael R.,Young, Ryan M.,Zhang, Long
, p. 8000 - 8010 (2021)
Colored charge-transfer complexes can be formed by the association between electron-rich donor and electron-deficient acceptor molecules, bringing about the narrowing of HOMO-LUMO energy gaps so that they become capable of harnessing visible light. In an effort to facilitate the use of these widespread, but nonetheless weak, interactions for visible light photocatalysis, it is important to render the interactions strong and robust. Herein, we employ a well-known donor-acceptor [2]catenane - formed by the mechanical interlocking of cyclobis(paraquat-p-phenylene) and 1,5-dinaphtho[38]crown-10 - in which the charge-transfer interactions between two 4,4′-bipyridinium and two 1,5-dioxynaphthalene units are enhanced by mechanical bonding, leading to increased absorption of visible light, even at low concentrations in solution. As a result, since this [2]catenane can generate persistent bipyridinium radical cations under continuous visible-light irradiation without the need for additional photosensitizers, it can display good catalytic activity in both photo-reductions and -oxidations, as demonstrated by hydrogen production - in the presence of platinum nanoparticles - and aerobic oxidation of organic sulfides, such as l-methionine, respectively. This research, which highlights the usefulness of nanoconfinement present in mechanically interlocked molecules for the reinforcement of weak interactions, can not only expand the potential of charge-transfer interactions in solar energy conversion and synthetic photocatalysis but also open up new possibilities for the development of active artificial molecular shuttles, switches, and machines.
Mo(VI) complex catalysed synthesis of sulfonees and their modification for anti-HIV activities
Madduluri, Vimal Kumar,Baig, Noorullah,Chander, Subhash,Murugesan, Sankaranarayanan,Sah, Ajay K.
, (2020/01/23)
An efficient method for the synthesis of sulfones has been developed using sugar derived cis-dioxo molybdenum(VI) complex as catalyst and urea hydrogen peroxide as oxygen source. Present method is highly specific for sulfide oxidation irrespective of presence of alkene and aldehyde groups in the same molecule. Synthesis of fifteen sulfones have been reported with 82–98% isolated yields and the catalyst has been reused five times without any loss in its activity. 2-(Phenylsulfonyl)aniline has been condensed with eight different aromatic aldehydes and the products are being explored for HIV-1 reverse transcriptase inhibition activities.
Kinetics and mechanism of iridium(III) catalysed oxidation of DL-methionine by alkaline hexacyanoferrate(III)
Dharma Rao,Baby Nirmala,Vani
, p. 365 - 371 (2013/05/22)
Iridium(III) catalysed oxidation of DL-methionine by hexacyanoferrate(III) was studied spectrophotometrically in aqueous alkaline medium at 30 ± 0.1°C at a constant ionic strength. A micro amount of iridium(III) was sufficient to catalyse the slow reaction between DL-methionine and hexacyanoferrate(III). The reaction is first order in both hexacyanoferrate(III) and iridium(III) concentrations. The order with respect to DL-methionine is fractional. Increase in the alkali concentration increases the reaction rate. Methionine sulfone was found to be the main product of oxidation and it was identified by IR and mass spectra. Hexacyanoferrate(II), the other product was found to have no effect on reaction rate. The active species of oxidant and catalyst are [Fe(CN)6]3- and [IrCl3(H 2O)2OH]- respectively. A possible mechanism was proposed and the activation parameters were computed with respect to the slow step of the reaction.
Halogenated fatty acid amides and cyclic depsipeptides from an eastern Caribbean collection of the cyanobacterium Lyngbya majuscula
Jimenez, Jorge I.,Vansach, Tifanie,Yoshida, Wesley Y.,Sakamoto, Bryan,Poerzgen, Peter,Horgen, F. David
supporting information; experimental part, p. 1573 - 1578 (2010/03/31)
A lipophilic extract of an eastern Caribbean collection of Lyngbya majuscula yielded two new halogenated fatty acid amides, grenadamides B (1) and C (2), and two new depsipeptides, itralamides A (3) and B (4), along with the known compounds hectochlorin a
Under-flame Reaction of Sulfur-containing Amino Acids by a Hydrogen-Oxygen Flame
Nomoto, Shinya,Shimoyama, Akira,Shiraishi, Susumu,Seno, Tomoyuki,Sahara, Denzo
, p. 643 - 649 (2007/10/03)
Methionine was subjected to a flame-induced reaction in water or in an aqueous formic acid solution by using a hydrogen (50%)-oxygen (50%), hydrogen (87%)-oxygen (13%) and hydrogen diffusion flame. Besides the already-known stepwise oxidation by a hydroxyl radical, the contribution of a hydrogen atom from the flame to the reaction was recognized when the hydrogen-rich mixtures were employed. Homoserine was obtained under all the reaction conditions employed here, and glutamic acid when employing aqueous formic acid as a solvent. A common intermediate, the 3-carboxy-3-aminopropyl radical, appeared to exist in the reaction pathway. A coupling reaction of this radical with a hydrogen atom, hydroxyl radical and hydroxycarbonyl radical afforded 2-aminobutyric acid, homoserine and glutamic acid, respectively. Lanthionine and S-methylcysteine underwent the same reactions. Increasing the hydrogen content of the fuel and adding formic acid to the solvent resulted in retarding the reaction rate. The latter modification of the reaction system also brought about greater stability of the reaction products.
