Reactions of N-Allyl- and N-Propargyltriflimides with N,N′-Disubstituted Carbodiimides
摘要:
The alkylating activity of N-allyl- and N-propargyltriflimides toward N,N-dicyclohexyl- and N,N-diphenylcarbodiimides has been studied. Activation of the nitrogen atom by two electron-withdrawing trifluoromethanesulfonyl groups favors cleavage of the C-N bond in the absence of a catalyst with the formation of N-substituted unsaturated ureas.
Facile Electrochemical Intramolecular Amination of Urea-Tethered Terminal Alkenes for the Synthesis of Cyclic Ureas
作者:Nisar Ahmed、Saira Khatoon
DOI:10.1002/open.201800064
日期:2018.8
Facile intramolecularamination of unactivated alkenes has been achieved by using electricity as a catalyst that helps to generate an intermediate and accelerates formation of cyclic ureas in high yields. Using this method, no metal catalysts were used. During electrolysis, a nitrogen radical was formed at the urea substrate that cyclised with the alkene and generated a terminal carbon radical which
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