25855-24-7Relevant articles and documents
Di-urea compounds as gelators for organic solvents
Van Esch, Jan,Kellogg, Richard M.,Feringa, Ben L.
, p. 281 - 284 (1997)
Simple diurea compounds form thermoreversible gels with several organic solvents. These gels are stable up to temperatures of 100°C, and can be stored for months. Electron microscopy reveals that in these solvents the gelation agents assemble into very thin rectangular sheets which are several tens of micrometers long.
P(III)-Assisted Electrochemical Access to Ureas via in situ Generation of Isocyanates from Hydroxamic Acids
Meng, Haiwen,Sun, Kunhui,Xu, Zhimin,Tian, Lifang,Wang, Yahui
supporting information, p. 1768 - 1772 (2021/03/26)
An external oxidant-free protocol for the generation of isocyanates from hydroxamic acids assisted by trivalent phosphine under mild electrochemical conditions was reported. The process started with the anodic oxidation of hydroxamic acids, followed by reacting with phosphine to form corresponding alkoxyphosphoniums and subsequent rearrangement with the release of tri-substituted phosphine oxide as the driving force to give isocyanates, which were trapped by N-based nucleophiles to produce various ureas. This method provides a broadly applicable procedure to access isocyanate intermediates under mild electrochemical conditions.
Formamides as Isocyanate Surrogates: A Mechanistically Driven Approach to the Development of Atom-Efficient, Selective Catalytic Syntheses of Ureas, Carbamates, and Heterocycles
Bruffaerts, Jeffrey,Von Wolff, Niklas,Diskin-Posner, Yael,Ben-David, Yehoshoa,Milstein, David
supporting information, p. 16486 - 16493 (2019/10/14)
Despite the hazardous nature of isocyanates, they remain key building blocks in bulk and fine chemical synthesis. By surrogating them with less potent and readily available formamide precursors, we herein demonstrate an alternative, mechanistic approach to selectively access a broad range of ureas, carbamates, and heterocycles via ruthenium-based pincer complex catalyzed acceptorless dehydrogenative coupling reactions. The design of these highly atom-efficient procedures was driven by the identification and characterization of the relevant organometallic complexes, uniquely exhibiting the trapping of an isocyanate intermediate. Density functional theory (DFT) calculations further contributed to shed light on the remarkably orchestrated chain of catalytic events, involving metal-ligand cooperation.