A general and mild Ullmann-type synthesis of diaryl ethers.
[reaction: see text] An efficient method for the synthesis of diaryl ethers under particularly mild conditions is described. Inexpensive ligands were found to greatly accelerate the Ullmann-type coupling of aryl bromides or iodides with phenols. A series of diaryl ethers were obtained with excellent yields in acetonitrile in the presence of Cs(2)CO(3) and catalytic copper(I) oxide. The reaction tolerates substrates with unfavorable substitution patterns, such as sterically hindered coupling partners or electron-rich aryl halides.
Cristau
Henri-Jean
HJ
Laboratoire de Chimie Organique (CNRS UMR 5076), Ecole Nationale Supérieure de Chimie de Montpellier, 8 rue de l'Ecole Normale, 34296 Montpellier Cedex 5, France.
Cellier
Pascal P
PP
Hamada
Samy
S
Spindler
Jean-Francis
JF
Taillefer
Marc
M