Pd(II)/Ag(I)-Promoted One-Pot Synthesis of Cyclic Ureas from (Hetero)Aromatic Amines and Isocyanates
作者:So Won Youn、Yi Hyun Kim
DOI:10.1021/acs.orglett.6b03151
日期:2016.12.2
A simple and facile one-pot reaction has been developed to afford a diverse range of N,N′-disubstituted benzimidazolones and imidazopyridinones containing two differently substituted N atoms. A cooperative Pd(II)/Ag(I) system promotes the sequential addition/intramolecular C–H amidationreaction of (hetero)aromatic amines and isocyanates, leading to the formation of two C–N bonds. A mechanism involving
已经开发出一种简单且容易的一锅反应,以提供包含两个不同取代的N原子的N,N'-二取代的苯并咪唑酮和咪唑并吡啶并酮的不同范围。协同的Pd(II)/ Ag(I)系统促进了(杂)芳族胺和异氰酸酯的顺序加成/分子内CH-H酰胺化反应,导致形成两个C-N键。一种机制,涉及在Ag 2 CO 3氧化剂和Pd(OAc)2存在下通过单电子转移(SET)生成的自由基中间体提出了路易斯酸。该协议使用易于获得的起始原料,良好的官能团耐受性和高效率,提供了一种操作简便,简单且可靠的方法。
A Novel C-N Migration Rearrangement Based on N-F Compounds for the Synthesis of <i>N</i>
-Alkyl Diaryl Ureas
作者:Yi-Xiao Zhao、Tian Xie、San-Ke Yang、Xian-Jin Yang
DOI:10.1002/ejoc.201901602
日期:2020.1.31
A novel aryl C–N shiftrearrangement reaction to form alkyl diaryl ureas from facilely available FPSBA derivatives was developed. FPSBA selectively reacted with secondary alkyl phenylamines to afford unsymmetrical alkyl diaryl ureas in good yields through a vicinal SN2′ mechanism rather than the traditional isocyanate intermediate pathway.
开发了一种新型的芳基C–N移位重排反应,可从容易获得的FPSBA衍生物形成烷基二芳基脲。FPSBA通过仲S N 2'机理而不是传统的异氰酸酯中间体途径与仲烷基苯胺选择性反应,以高收率提供不对称的烷基二芳基脲。
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
Diazanickelacyclopentanone aus nickel(0), iminen und isocyanaten
作者:Heinz Hoberg、Klaus Sümmermann
DOI:10.1016/s0022-328x(00)99233-7
日期:1983.9
Isocyanates are oxidatively coupled with imines at nickel(0) under the influence of basic chelate ligands to form diazanickelacyclopentanones. The structure of these novel five-membered nickelacycles has been determined by spectroscopic and chemical methods. The mechanism of the coupling reaction is discussed.