Synthesis of Aryl Ethers from Aromatic Carboxylic Acids

A silver/copper bimetallic catalyst system promotes the decarboxylative Chan–Evans–Lam alkoxylation of ortho -substituted aromatic carboxylate salts with tetraalkyl orthosilicates or triaryl borates. Non- ortho -substituted carboxylates are alkoxylated via an ortho -C–H-alkoxylation with concomitant cleavage of the carboxylate directing group via protodecarboxylation. This way, meta -substituted carboxylates are converted into para -substituted alkoxyarenes and vice versa. The combined processes provide a convenient synthetic entry to the important class of aromatic ethers from widely available carboxylic acids.