A ligand-free palladium-catalyzed aerobic oxidative carbonylation of amines for the synthesis of ureas, particular unsymmetrically N,N′-disubstituted ureas, which cannot be accessed by any other palladium-catalyzed oxidative carbonylation of amines to date, is presented. An array of symmetrical and unsymmetrical ureas were straightforwardly synthesized by using inexpensive, readily available, stable
Palladium-catalyzed synthesis of symmetrical urea derivatives by oxidative carbonylation of primary amines in carbon dioxide medium
作者:Nicola Della Ca’、Paolo Bottarelli、Angela Dibenedetto、Michele Aresta、Bartolo Gabriele、Giuseppe Salerno、Mirco Costa
DOI:10.1016/j.jcat.2011.06.003
日期:2011.8
An efficient palladium-catalyzed synthesis of symmetrically disubstituted ureas via oxidative carbonylation of primary amines is described. The reactions are carried out in the presence of a large excess of carbondioxide as reaction medium or under solvent-free conditions. The adopted catalyst such as potassium tetraiodopalladate, stable and easy to prepare, allows the use of air as a cheap oxidizing
Organic-Fluorous Phase Switches: A Fluorous Amine Scavenger for Purification in Solution Phase Parallel Synthesis
作者:Bruno Linclau、Ashvani K. Sing、Dennis P. Curran
DOI:10.1021/jo9823442
日期:1999.4.1
The synthesis of the fluorousamine scavenger [(C(6)F(13)CH(2)CH(2))(3)SiCH(2)CH(2)CH(2)](2)NH and its successful application in the automated solution phase parallel synthesis of a urea library are described. Ureas were made by robotic synthesis from organic amines and excess isocyanates. The amine scavenger reacts with excess isocyanate, and the fluorous tag serves to solubilize the resulting adduct