Decarboxylative Biaryl Synthesis from Aromatic Carboxylates and Aryl Triflates

A new catalyst system, generated in situ from Cu2O, 1,10-phenanthroline, Pdl(2), and Tol-BINAP, for the first time allows the decarboxylative coupling of carboxylic acids with aryl triflates. In contrast to previous decarboxylative couplings that remained limited to certain activated carboxytates, e.g., ortho-substituted benzoates, this halide-free protocol is generally applicable to aromatic carboxylic acid salts regardless of their substitution pattern.