Abstract A facile access to the synthesis of alkyl and aryl oxime esters of ketoximes and aldoximes in high yields (90–97%) is reported. The reactions were performed using N-[3-(methylamino)propyl]-N′-ethylcarbodiimide hydrochloride (EDCI) reagent in the presence of 4-(dimethylamino)pyridine (DMAP) as a catalyst at room temperature. The isolation and purification of products is very simple and in cases
Structure Correlation Study of the Beckmann Rearrangement: X-ray Structural Analysis and 13C–13C 1-Bond Coupling Constant Study of a Range of Cyclohexanone Oxime Derivatives
作者:Shin Dee Yeoh、Benjamin L. Harris、Tristan J. Simons、Jonathan M. White
DOI:10.1071/ch12079
日期:——
rearrangement in the ground state structures of these oxime derivatives. The carbon–carbon bond distances of the participating carbons in this rearrangement, however, did not vary in a systematic way with the electron demand of the OR substituent, suggesting that the structural effects are too small to be detected using X-ray crystallography. However, the 13C–13C 1-bond coupling constants, which are sensitive
一系列环己酮和4-叔肟肟衍生物(1和4)的X射线结构确定了丁基丁基己酮,其中肟氮(OR)上的氧化取代基的电子需求被系统地改变。可以确定的是,随着OR基团对电子的需求增加,N-OR键的距离也会增加,这与键断裂的早期阶段是一致的。与这种结构效应同时出现的是,N1-C1-C2键角明显关闭,这与反平面碳向氮取代基迁移的早期阶段一致。这些结构效应与这些肟衍生物的基态结构中贝克曼重排早期的表现相一致。但是,在这种重排中,参与的碳的碳-碳键距离并未随OR取代基的电子需求而系统地变化,这表明结构效应太小而无法使用X射线晶体学检测到。然而对超共轭作用敏感的13 C– 13 C 1键耦合常数显示出随着OR取代基的电子需求而系统地变化。2,2-二甲基环己酮肟5衍生物的结构效应相似,但幅度较小,2,2-二甲基环己酮是一种容易发生贝克曼断裂而不是贝克曼重排的底物。
Gass; Bope, Journal of the American Pharmaceutical Association (1912), 1959, vol. 48, p. 186,188
作者:Gass、Bope
DOI:——
日期:——
A Novel Synthesis of Carboxylic Acid Oxime Esters Catalyzed by 2-(1H-Benzotriazole-1-yl)-1,1,3,3-tetramethyluronium Tetrafluoroborate
We describe a facile synthesis of carboxylic acid oxime esters in acetonitrile from the corresponding carboxylic acids and oximes catalyzed by 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate in the presence of triethylamine at room temperature under mild conditions.