546-88-3Relevant articles and documents
Munson,Connors
, p. 1979,1980-1984 (1972)
N-O Bond Fission as the Rate-Determining Step in the Aqueous Conversion of N-Peptidyl-O-(p-nitrobenzoyl)hydroxylamines to p-Nitrobenzoic Acid and Peptidylhydroxamic Acids
Demuth, Hans-Ulrich,Fischer, G.,Barth, A.,Schowen, R. L.
, p. 5880 - 5883 (1989)
N-Acetyl-, N-alanyl-alanyl-, N-alanyl-prolyl-, and N-Boc-alanyl-prolyl-O-(p-nitrobenzoyl) hydroxylamines, compounds that are mechanism-based irreversible inactivators of some proteolytic enzymes, are degraded in aqueous buffers at neutral pH to p-nitrobenzoic acid and either the corresponding N-acylhydroxamic acid or products of its further degradation such as the diketopiperazine.At neutral pH, the reactants exist as the monoanion, as a result of the acidity of the -CO-NH-O- linkage.The p-nitrobenzoic acid formed in a mixture of 50percent H2(18)O and 50percent H2(16)O contains less than 2percent (18)O, which shows that nucleophilic attack of water at the ester carbonyl is not occuring in the degradation.The decomposition of the N-alanyl-prolyl derivative, labeled with (15)N at the N-O nitrogen, exhibits a kinetic isotope effect k14/k15 = 1.092 +/- 0.056, suggesting that N-O fission is occuring in the rate-determining step of the degradation.Kinetic solvent isotope effects of 1.02-1.15 are inconsistent with an expectation of factors around 2 or greater for spontaneous hydrolysis of the ester linkage.All derivatives have ΔH* = 24-27 kcal/mol and ΔS* = +4-7 eu, consistent with unimolecular fission of the substrate N-O to generate p-nitrobenzoate ion and the acyl nitrene.The nitrene must suffer nucleophilic attack at nitrogen very rapidly, producing the hydroxamic acid as the initial product.In the peptide derivatives, further reaction to the cyclized products results.
Activation and Orientation by Receptor-Substrate Binding. The Case of Acyl Transfer from O-Acetylhydroxylamine
Lehn, Jean-Marie,Nishiya, Takako
, p. 215 - 218 (1987)
The strong binding ability of the receptor molecule 1 induces complexation of O-acetylhydroxylamine and of hydroxylamine in their protonated forms; as a result, subsequent reaction of bound CH3COONH3+ becomes fast and selective, giving only acetic acid with a rate enhancement by a factor of about 30.
Bamberger,Seligman
, p. 3885 (1902)
Hydroxamic acids. II. Kinetics and mechanisms of hydroxyaminolysis of succinimide.
Notari
, p. 1064 - 1068 (1969)
-
Novel fluorinated 7-hydroxycoumarin derivatives containing an oxime ether moiety: Design, synthesis, crystal structure and biological evaluation
Dai, Peng,Jiao, Jian,Wang, Qing-Qing,Zhang, Shu-Guang,Zhang, Wei-Hua
, (2021/06/28)
A series of fluorinated 7-hydroxycoumarin derivatives containing an oxime ether moiety have been designed, synthesized and evaluated for their antifungal activity. All the target compounds were determined by1H-NMR,13C-NMR, FTIR and HR-MS spectra. The single-crystal structures of compounds 4e, 4h, 5h and 6c were further confirmed using X-ray diffraction. The antifungal activities against Botrytis cinerea (B. cinerea), Alternaria solani (A. solani), Gibberella zeae (G. zeae), Rhizoctorzia solani (R. solani), Colletotrichum orbiculare (C. orbiculare) and Alternaria alternata (A. alternata) were evaluated in vitro. The preliminary bioassays showed that some of the designed compounds displayed the promising antifungal activities against the above tested fungi. Strikingly, the target compounds 5f and 6h exhibited outstanding antifungal activity against B. cinerea at 100 μg/mL, with the corresponding inhibition rates reached 90.1 and 85.0%, which were better than the positive control Osthole (83.6%) and Azoxystrobin (46.5%). The compound 5f was identified as the promising fungicide candidate against B. cinerea with the EC50 values of 5.75 μg/mL, which was obviously better than Osthole (33.20 μg/mL) and Azoxystrobin (64.95 μg/mL). Meanwhile, the compound 5f showed remarkable antifungal activities against R. solani with the EC50 values of 28.96 μg/mL, which was better than Osthole (67.18 μg/mL) and equivalent to Azoxystrobin (21.34 μg/mL). The results provide a significant foundation for the search of novel fluorinated 7-hydroxycoumarin derivatives with good antifungal activity.
Alternating Current Electrolysis as Efficient Tool for the Direct Electrochemical Oxidation of Hydroxamic Acids for Acyl Nitroso Diels–Alder Reactions
F?hrmann, Jan,Hilt, Gerhard
supporting information, p. 20313 - 20317 (2021/08/12)
The acyl nitroso Diels–Alder reaction of 1,3-dienes with electrochemically oxidised hydroxamic acids is described. By using alternating current electrolysis, their typical electro-induced decomposition could be suppressed in favour of the 1,2-oxazine cycloaddition products. The reaction was optimised using Design of Experiments (DoE) and a sensitivity test was conducted. A mixture of triethylamine/hexafluoroisopropanol served as supporting electrolyte in dichloromethane, thus giving products of high purity after evaporation of the volatiles without further purification. The optimised reaction conditions were applied to various 1,3-dienes and hydroxamic acids, giving up to 96 % isolated yield.