61077-21-2Relevant academic research and scientific papers
Base-promoted aromatic [3,3] sigmatropic rearrangement of N-acyl-O-arylhydroxylamine derivatives
Tayama, Eiji,Hirano, Kazuki
, p. 665 - 673 (2019/01/04)
The base-promoted aromatic [3,3] sigmatropic rearrangement of N-acyl-O-arylhydroxylamines giving α-(2-hydroxyphenyl)amides was successfully demonstrated. The substrates were prepared from N-substituted hydroxylamines by N-acylation followed by copper(I)-mediated O-arylation with boronic acids. Treatment of the substrates with lithium hexamethyldisilazide (LiHMDS) in THF at 0 °C to room temperature generated the corresponding amide enolates. The aromatic [3,3] rearrangement of the enolates provided the desired products in moderate to good yields. A crossover experiment produced only intramolecular products and clarified that the reaction proceeds via the aromatic [3,3] sigmatropic rearrangement, not a bond-cleavage–recombination process. Our method is a formal α-arylation of amides.
THE CONFORMATIONAL BEHAVIOUR OF HYDROXAMIC ACIDS
Kolasa, T.
, p. 1753 - 1760 (2007/10/02)
N-Formyl-N-alkylhydroxylamines, N-formyl-α-N-hydroxyamino-acid esters and some N-acetyl analogues exist as Z/E equilibrium mixtures, as shown by H-NMR and IR.The dependence of the Z/E ratio on the nature of N-substituents, acyl groups and solvent was stud
