A short review article, also from the group of Igor Larrosa at Manchester, on the use of aromatic carboxylic acids as coupling partners in biaryl synthesis, appeared earlier in European Journal of Organic Chemistry (2017, 3517-3527). It is suggested in the micro-review that benzoic acid derivatives are atom-economic alternatives to traditional cross coupling partners, and are cheap, readily available and shelf stable reagents. Coupling can occur with either an arene or a second benzoic acid derivative.
Early examples used stoichiometric silver carbonate along with Pd catalysts but these are sometimes being replaced by copper or nickel catalysts.
