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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Palladium(II)-Catalyzed C(sp2)-H Bond Activation/C-N Bond Cleavage Annulation of N-Methoxy Amides and Arynes
Cheng, Xiu-Fen,Yu, Ting,Liu, Yi,Wang, Nan,Chen, Zhenzhen,Zhang, Guang-Lu,Tong, Lili,Tang, Bo
, p. 2087 - 2092 (2022/04/07)
The Pd(II)-catalyzed C-H bond activation/C-N bond cleavage annulation reaction of N-alkyoxyamide aryne is developed to synthesize 9,10-dihydrophenanthrenone derivatives. This reaction exhibited good functional group compatibility with yields up to 92%. Detailed mechanistic studies showed that the key to C-N bond cleavage is the formed eight-membered palladacycle intermediate undergoing nucleophilic addition to the carbonyl group, which provides a new and practical way for N-alkoxyamide directed C-H bond activation.
Reactivity of secondary N-alkyl acrylamides in Morita–Baylis–Hillman reactions
Ahmar, Mohammed,Queneau, Yves,Verrier, Charlie,Yue, Xiaoyang
, p. 319 - 330 (2021/10/29)
The Morita–Baylis–Hillman (MBH) reaction of secondary N-alkyl acrylamides, discarded up to now from investigations of the scope of activated alkenes, was studied. Optimization of the reaction conditions revealed that a balance must be found between activation of the MBH coupling reaction and that of the undesired competitive aldehyde Cannizzaro reaction. Using 3-Hydroxyquinuclidine (3-HQD) in a 1:1 water-2-MeTHF mixture provides the appropriate conditions that were applicable to a wide range of diversely substituted secondary N-alkyl acrylamides and aromatic aldehydes, giving rise to novel amide-containing MBH adducts under mild and clean conditions.
