75735-30-7Relevant academic research and scientific papers
Chemoselective amide formation using O-(4-nitrophenyl)hydroxylamines and pyruvic acid derivatives
Kumar, Sonali,Sharma, Rashi,Garcia, Megan,Kamel, Joseph,McCarthy, Caroline,Muth, Aaron,Phanstiel, Otto
, p. 10835 - 10845 (2013/02/23)
A series of O-(4-nitrophenyl)hydroxylamines were synthesized from their respective oximes using a pulsed addition of excess NaBH3CN at pH 3 in 65a-75% yield. Steric hindrance near the oxime functional group played a key role in both the ease by which the oxime could be reduced and the subsequent reactivity of the respective hydroxylamine. Reaction of the respective hydroxylamines with pyruvic acid derivatives generated the desired amides in good yields. A comparison of phenethylamine systems bearing different leaving groups revealed significant differences in the rates of these systems and suggested that the leaving group ability of the Na-OR substituent plays an important role in determining their reactivity with pyruvic acid. Competition experiments (in 68% DMSO/phosphate buffered saline) using 1 equiv of N-phenethyl-O-(4-nitrophenyl)hydroxylamine and 2 equiv of pyruvic acid in the presence of other nucleophiles such as glycine, cysteine, phenol, hexanoic acid, and lysine demonstrated that significant chemoselectivity is present in this reaction. The results suggest that this chemoselective reaction can occur in the presence of excess α-amino acids, phenols, acids, thiols, and amines.
Nitrile-forming Eliminations from Oxime Ethers
Hegarty, Anthony F.,Tuohey, Patrick J.
, p. 1313 - 1317 (2007/10/02)
The oxime ethers (7) and (8) (R = alkyl or aryl) undergo base-catalysed elimination to benzonitriles (3) in water-dioxan (4 : 1) at 25 deg C.The Z-isomer (8Z) reacts via hydroxide-catalysed antiperiplanar elimination 70-fold more rapidly than the corresponding E-isomer.Electronic effects on syn-elimination (from 7E) show that electron-withdrawing groups aid elimination in both Ar and in the leaving group -OR; no intramolecular assistance is observed in these substrates.These results are interpreted in terms of a central E2 elimination, with appreciable C-H and N-O- bond cleavage in the transition state.
