619-73-8Relevant articles and documents
Cyclic voltammetry and XPS analyses of graphite felt derivatized by non-Kolbe reactions in aqueous media
Geneste, Florence,Cadoret, Mael,Moinet, Claude,Jezequel, Guy
, p. 1261 - 1266 (2002)
This present work describes a preliminary study of modification of graphite felt for future applications in indirect electrolysis. The anodic oxidation of electroactive carboxylate compounds was achieved in aqueous media. The derivatization of the electrode was highlighted by cyclic voltammetry and XPS analyses. Interestingly, the grafting process led to chemically stable covalent attachment of nitroaryl species on the graphite felt with simultaneous increase of its real surface area. The comparison with the process performed in acetonitrile underlines the role of graphite oxidation in the immobilization of the molecules on the felt.
Structural basis of the broad substrate tolerance of the antibody 7B9-catalyzed hydrolysis of p-nitrobenzyl esters
Miyamoto, Naoki,Yoshimura, Miho,Okubo, Yuji,Suzuki-Nagata, Kayo,Tsumuraya, Takeshi,Ito, Nobutoshi,Fujii, Ikuo
, p. 1412 - 1417 (2018)
Catalytic antibody 7B9, which was elicited against p-nitrobenzyl phosphonate transition-state analogue (TSA) 1, hydrolyzes a wide range of p-nitrobenzyl monoesters and thus shows broad substrate tolerance. To reveal the molecular basis of this substrate tolerance, the 7B9 Fab fragment complexed with p-nitrobenzyl ethylphosphonate 2 was crystallized and the three-dimensional structure was determined. The crystal structure showed that the strongly antigenic p-nitrobenzyl moiety occupied a relatively shallow antigen-combining site and therefore the alkyl moiety was located outside the pocket. These results support the observed broad substrate tolerance of 7B9 and help rationalize how 7B9 can catalyze various p-nitrobenzyl ester derivatives. The crystal structure also showed that three amino acid residues (AsnH33, SerH95, and ArgL96) were placed in key positions to form hydrogen bonds with the phosphonate oxygens of the transitions-state analogue. In addition, the role of these amino acid residues was examined by site-directed mutagenesis to alanine: all mutants (AsnH33Ala, SerH95Ala, and ArgL96Ala) showed no detectable catalytic activity. Coupling the findings from our structural studies with these mutagenesis results clarified the structural basis of the observed broad substrate tolerance of antibody 7B9-catalyzed hydrolyses. Our findings provide new strategies for the generation of catalytic antibodies that accept a broad range of substrates, aiding their practical application in synthetic organic chemistry.
Primary Amine–Promoted Ring Opening in Carbapenem-derived p-Nitrobenzyl Esters
Galeeva, А.М.,Lobov, А. N.,Miftakhov, М. S.,Valiullina, Z. R.
, (2020)
Abstract: Ethylamine and ethanolamine react with 4-nitrobenzyl (4R,5S,6S)-3-[(2-furylmethyl)sulfanyl]-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate, leading to the opening of the β-lactam ring by C7–N bond c
Synthesis of 10,10-dimethylprostaglandin F1 and F2 analogues
Plantema,De Koning,Huisman
, p. 268 - 275 (1983)
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Method for Controlled Release Using Mechanical Force
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Paragraph 0049, (2022/03/19)
A general and modular mechanophore platform that efficiently releases a cargo molecule via a mechanically triggered cascade reaction is described, along with methods of synthesis and use thereof. The mechanophore platform comprises a stable Diels-Alder adduct mechanophore comprising a 2-furylcarbinol derivative as its diene component, wherein the 2-furylcarbinol derivative is, in turn, pre-loaded with a covalently attached cargo molecule, and wherein the Diels-Alder adduct mechanophore is embedded into a polymer chain or polymer network, such that the mechanophore platform undergoes the retro [4+2] cycloaddition reaction under mechanical force to reveal the unstable2-furylcarbinol derivative, which, in turn, easily decomposes under mild conditions to release its molecule cargo.
Hf-MOF catalyzed Meerwein?Ponndorf?Verley (MPV) reduction reaction: Insight into reaction mechanism
Lin, Yamei,Bu, Qingxia,Xu, Jiaxian,Liu, Xiao,Zhang, Xueping,Lu, Guo-Ping,Zhou, Baojing
, (2021/01/25)
Hf-MOF-808 exhibits excellent activity and specific selectivity on the hydrogenation of carbonyl compounds via a hydrogen transfer strategy. Its superior activity than other Hf-MOFs is attributed to its poor crystallinity, defects and large specific surface area, thereby containing more Lewis acid-base sites which promote this reaction. Density functional theory (DFT) computations are performed to explore the catalytic mechanism. The results indicate that alcohol and ketone fill the defects of Hf-MOF to form a six-membered ring transition state (TS) complex, in which Hf as the center of Lewis stearic acid coordinates with the oxygen of the substrate molecule, thus effectively promoting hydrogen transfer process. Other reactive groups, such as –NO2, C = C, -CN, of inadequate hardness or large steric hindrance are difficult to coordinate with Hf, thus weakening their catalytic effect, which explains the specific selectivity Hf-MOF-808 for reducing the carbonyl group.