The copper‐catalyzed decarboxylation of carboxylic aromaticacids has been advantageously achieved by using aliphatic amines like tetramethylethylenediamine (TMEDA) or hexamethylenetetraamine (HMTA) as ligands instead of the aromatic heterocyclic amines (quinoline, phenanthroline) used until now. The improvement is significant since the reaction can be performed at a lower temperature (ca. 50 °C less)
A novel copper-catalyzed decarboxylative methylthiolation of arenecarboxylate salts has been realized using DMSO as the methylthiolation source. Various potassium arylcarboxylates underwent decarboxylative methylthiolation under air to furnish the corresponding aryl methyl thioethers in moderate to excellent yields. The reaction tolerated a wide variety of functional groups. Notably, the synthesis
Synthesis of Biaryls by Decarboxylative Hiyama Coupling
作者:Dmitry Katayev、Benjamin Exner、Lukas J. Gooßen
DOI:10.1002/cctc.201500068
日期:2015.7.13
A trimetallic palladium/copper/silver system has been developed that allows the decarboxylativeHiyamacoupling of ortho‐substituted aryl carboxylates with trialkoxyarylsilanes to give the corresponding biaryls. The cross‐coupling is catalyzed by a Pd/N‐heterocyclic carbene complex with silver carbonate aiding its reoxidation. Copper(II) fluoride acts as decarboxylation catalyst, stoichiometric oxidant
CuSO4-mediated decarboxylative C-N cross-coupling of aromatic carboxylic acid with amide has been developed, leading to N-arylamides in modest to excellent yields. Anilines bearing electron-withdrawing substituents could also couple efficiently with aromatic carboxylic acids to give diarylamines in good to excellent yields. (C) 2014 Published by Elsevier Ltd.