2592-95-2Relevant articles and documents
Synthesis and morpholinolysis of N,N-diethyl carbamate derivatives of 4- HOAt, 7-HOAt and HOBt
Khattab, Sherine N.,Hassan, Seham Y.,Hamed, Ezzat A.,El-Faham, Ayman
, p. 247 - 251 (2007)
N,N-Diethyl carbamates of 1-hydroxy-7-azabenzotriazole (7-HOAt), 1-hydroxy-4-azabenzotriazole (4-HOAt), 1-hydroxybenzotriazole (HOBt), and 1-hydroxypyrrolidine-2,5-dione have been synthesised. The reactivities of these active esters have been determined by studying the kinetics and mechanism of their morpholinolysis in acetonitrile at different temperatures.
Highly efficient one-pot assembly of peptides by double chemoselective coupling
Sampaio-Dias, Ivo E.,Sousa, Carlos A. D.,Silva-Reis, Sara C.,Ribeiro, Sara,García-Mera, Xerardo,Rodríguez-Borges, José E.
supporting information, p. 7533 - 7542 (2017/09/27)
This study describes a methodological advancement in solution-phase peptide synthesis via the development of a convenient and operational protocol to synthesize oligopeptides in a one-pot three-step cascade method, in which two peptide bonds are introduced chemoselectively. Tri- to hexapeptides were obtained in high global yields (80-95%) with virtually no epimerization as determined via HPLC. The methodology described herein represents a faster, easier and milder approach to the synthesis of peptides, and it operates at equimolar amounts. This protocol comprises the formation of secondary and tertiary amides and is compatible with Z, Boc and Fmoc N-protecting groups as well as the use of d/l and non-proteinogenic amino acids.
Importance of π-stacking interactions in the hydrogen atom transfer reactions from activated phenols to short-lived N-oxyl radicals
Mazzonna, Marco,Bietti, Massimo,Dilabio, Gino A.,Lanzalunga, Osvaldo,Salamone, Michela
, p. 5209 - 5218 (2014/06/23)
A kinetic study of the hydrogen atom transfer from activated phenols (2,6-dimethyl- and 2,6-di-tert-butyl-4-substituted phenols, 2,2,5,7,8- pentamethylchroman-6-ol, caffeic acid, and (+)-cathechin) to a series of N-oxyl radical (4-substituted phthalimide-N-oxyl radicals (4-X-PINO), 6-substituted benzotriazole-N-oxyl radicals (6-Y-BTNO), 3-quinazolin-4-one-N-oxyl radical (QONO), and 3-benzotriazin-4-one-N-oxyl radical (BONO)), was carried out by laser flash photolysis in CH3CN. A significant effect of the N-oxyl radical structure on the hydrogen transfer rate constants (kH) was observed with kH values that monotonically increase with increasing NO-H bond dissociation energy (BDENO-H) of the N-hydroxylamines. The analysis of the kinetic data coupled to the results of theoretical calculations indicates that these reactions proceed by a hydrogen atom transfer (HAT) mechanism where the N-oxyl radical and the phenolic aromatic rings adopt a π-stacked arrangement. Theoretical calculations also showed pronounced structural effects of the N-oxyl radicals on the charge transfer occurring in the π-stacked conformation. Comparison of the kH values measured in this study with those previously reported for hydrogen atom transfer to the cumylperoxyl radical indicates that 6-CH3-BTNO is the best N-oxyl radical to be used as a model for evaluating the radical scavenging ability of phenolic antioxidants.