Zinc Powder Catalysed Formylation and Urealation of Amines Using
<scp>
CO
<sub>2</sub>
</scp>
as a
<scp>C1</scp>
Building Block
<sup>†</sup>
作者:Chongyang Du、Yaofeng Chen
DOI:10.1002/cjoc.202000072
日期:2020.10
valuable organiccompounds catalysed by cheap and biocompatible metal catalysts is one of important topics of current organic synthesis and catalysis. Herein, we report the zinc powder catalysed formylation and urealation of amines with CO2 and (EtO)3SiH under solvent free condition. Using 2 mol% zinc powder as the catalyst, a series of secondary amines, both the aromatic ones and the aliphatic ones,
Synthesis of Urea Derivatives from CO
<sub>2</sub>
and Silylamines
作者:Maotong Xu、Andrew R. Jupp、Maegan S. E. Ong、Katherine I. Burton、Saurabh S. Chitnis、Douglas W. Stephan
DOI:10.1002/anie.201900058
日期:2019.4.16
A series of thirty‐three N,N′‐diaryl, dialkyl, and alkyl‐aryl ureas have been prepared in pyridine or toluene by reaction of silylamines with CO2. This protocol is shown to provide facile access to 13C‐labeled ureas, as well as chiral and macrocyclic ureas. These reactions proceed through initial generation of the corresponding silylcarbamates, which subsequently react with silylamine under thermal
Anionic activation by fluoride ion in solid-liquid systems
作者:S. Sebti、A. Foucaud
DOI:10.1016/s0040-4020(01)87355-5
日期:1986.1
and 2-acyloxy 3-oxo 2,3-diphenylpropanamides 13 under anionic activation by cesium fluoride was studied. The fluoride ion is an efficient base for the heterocyclization of 1 into 3 (2H)-furanones and 2 (5H)-furanones, but the hydrolysis of the ester group lowered the selectivity of the reaction. However, the cleavage of 13 into the esters 14 and the cyclization of 3-benzoyloxy 3-methyl 2-butanone into
A stability-indicating UV assay was developed for xilobam, a member of a new class of CNS agents. The method was specific, precise, and accurate. TLC and high-pressure liquid chromatography were used to support method specificity. Xilobam is sensitive to heat, moisture, and basic conditions. The degradation products were identified as N-methylpyrrolidone, 2,6-dimethylaniline, and N,N'-bis(2,6-dimethyl-phenyl)urea
A highly efficientoxidativecarbonylation reaction of amines to ureas was developed making use of carbene–palladiumcomplexes in the absence of any promoter. Both aliphatic amines and aromatic amines were transformed in good to excellent yields to the expected ureas.