717-19-1Relevant academic research and scientific papers
Direct Observation of Acyl Nitroso Compounds in Aqueous Solution and the Kinetics of Their Reactions with Amines, Thiols, and Hydroxamic Acids
Maimon, Eric,Lerner, Ana,Samuni, Amram,Goldstein, Sara
, p. 7006 - 7013 (2018/09/06)
Acyl nitroso compounds or nitrosocarhonyls (RC(O)N=O) are reactive short-lived electrophiles, and their hydrolysis and reactions with nucleophiles produce HNO. Previously, direct detection of acyl nitroso species in nonaqueous media has been provided by time-resolved infrared spectroscopy demonstrating that its half-life is about 1 ms. In the present study hydroxamic acids (RC(O)NHOH) are oxidized electrochemically in buffered aqueous solutions (pH 5.9-10.2) yielding transient species characterized by their maximal absorption at 314-330 nm. These transient species decompose via a first-order reaction yielding mainly HNO and the respective carboxylic acid and therefore are ascribed to RC(O)N=O. The sufficiently long half-life of RC(O)N=O in aqueous solution allows for the first time the study of the kinetics of its reactions with various nucleophiles demonstrating that the nucleophilic reactivity follows the order thiolate > hydroxamate > amine. Metal chelates of CH3C(O)NHOH catalyze the hydrolysis of CH3C(O)N=O at the efficacy order of CuII > ZnII > NiII > CoII where only CuII catalyzes the hydrolysis also in the absence of the hydroxamate. Finally, oxidation of hydroxamic acids generates HNO, and the rate of this process is determined by the half-life of the respective acyl nitroso compound.
Organocatalysis with cysteine derivatives: Recoverable and cheap chiral catalyst for direct aldol reactions
Li, Shi,Fu, Xiangkai,Wu, Chuanlong
experimental part, p. 195 - 205 (2012/05/20)
Highly enantioselective, recoverable and cheap cysteine derivatives have been developed with improved solubility properties in common, nonpolar organic solvents. The reactions were catalyzed using 5 mol% 1e, and the aldol products could be obtained with up to 99:1 syn/anti ratio and >99% ee. The catalyst could be easily recovered and reused, with only a slight decrease of enantioselectivity observed for five cycles. Catalyst 1e can be efficiently used in large-scale reactions with enantioselectivity being maintained at the same level, which offers great possibility for application in industry. Springer Science+Business Media B.V. 2011.
Selective synthesis and structural elucidation of S-acyl- and N-acylcysteines
Katritzky, Alan R.,Tala, Srinivasa R.,Abo-Dya, Nader E.,Gyanda, Kapil,El-Gendy, Bahaa El-Dien M.,Abdel-Samii, Zakaria K.,Steel, Peter J.
experimental part, p. 7165 - 7167 (2009/12/09)
(Chemical Equation Presented) N-(Acyl)-1H-benzotriazoles 6a-f react with L-cysteine 5 at 20°C to give exclusively (i) N-acyl-L-cysteines 8a-e in the presence of triethylamine in CH3CN-H2O (3:1), but (ii) S-acyl-L-cysteines 7a-e in CH
