Infrared spectroscopic and conformational studies of trisubstituted ureas containing chlorophenyl groups
作者:Yoshiuki Mido、Chizuko Furusawa
DOI:10.1016/0022-2860(82)85229-0
日期:1982.6
trans — cis isomerism about the NH-CO rotational axis is discussed in relation to the steric effect of the R 2 group, Ph-Ph interaction and inter- and intra-molecular hydrogen bonding. In dilute solution, R 2 UPhCl exists in the trans or the out form, and RPhUPhCl in the cisform o -Chlorophenyl derivatives show a monomeric v (N-H) band at a wavenumber lower than that of the other derivatives and no
摘要 为了检验引入的氯原子的影响,研究了含有氯苯基的三取代脲 R 2 UPhCl 和 RPhUPhCl [U = NC(O)NH] 在 ν(NH) 区域的红外光谱。围绕 NH-CO 旋转轴的反-反-顺异构现象与 R 2 基团的空间效应、Ph-Ph 相互作用以及分子间和分子内氢键有关。在稀溶液中,R 2 UPhCl 以反式或反式存在,而顺式 RPhUPhCl 邻氯苯基衍生物在波数低于其他衍生物的波数处显示出单体 v (NH) 带,并且没有相关联的 v (NH) ) 在浓溶液或什至在饱和溶液中的条带。
2,2,2-Trifluroenthanol promoted synthesis of unsymmetrical ureas from dioxazolones and amines via tandem lossen rearrangement/condensation process
(TFE) promoted synthesis of unsymmetric ureas was described. This approach enabled the construction of a variety of ureas from the readily prepared and easy-to-handle dioxazolones and amines viatandem Lossen rearrangement/condensation process. The reaction featured mild conditions for the urea synthesis under metal-free conditions, which was successively applied in the scale-up synthesis of herbicides
Metal-Free Oxidative C-H Amidation of<i>N</i>,<i>N′</i>-Diarylureas with PhI(OAc)<sub>2</sub>: Synthesis of Benzimidazol-2-one Derivatives
作者:Jipan Yu、Chang Gao、Zhixuan Song、Haijun Yang、Hua Fu
DOI:10.1002/ejoc.201500726
日期:2015.9
compounds or intramolecular N-arylations using substrates with carbon-halogen bonds. However, the starting materials of these protocols are often not readily available. Herein, a simple and practical metal-free oxidative C–H amidation of N,N′-diarylureas has been developed that takes place at room temperature. This protocol uses readily available N,N′-diarylureas as the starting materials and inexpensive
Catalyst‐Free Electrosynthesis of Benzimidazolones through Intramolecular Oxidative C−N Coupling
作者:Jiang‐Sheng Li、Pan‐Pan Yang、Xin‐Yun Xie、Si Jiang、Li Tao、Zhi‐Wei Li、Cui‐Hong Lu、Wei‐Dong Liu
DOI:10.1002/adsc.202000198
日期:2020.5.12
The electrochemicalsynthesis of N, N’‐disubstituted benzimidazolones from ureas through an intramolecular anodic dehydrogenative N−H/C−H coupling has been developed. The reaction undergoes under the undivided electrolysis conditions and obviates the need for any catalysts and chemical oxidants.
alkylation of a methyl group, on di‐ and trisubstituted ureas, with terminalalkenes by C(sp3)−Hbondactivation proceeded in the presence of a hydroxoiridium/bisphosphine catalyst to give high yields of the corresponding addition products. The hydroxoiridium/bisphosphine complex generates an amidoiridium intermediate by reaction with ureas having an N−H bond.