Monophasic Pd-catalysed O-arylation of phenols

Diaryl ethers represent a common motif in drugs, agrochemicals, and natural products. Their synthesis via C–O cross-coupling typically employs an inorganic base, resulting in reaction heterogeneity that leads to irreproducibility between laboratories and scales. Our group recently developed a Pd-catalysed C–O coupling of phenols and aryl triflates that uses a weak, soluble organic base. This fully homogeneous system is compatible with automated synthesis, microwave heating, and scale-up in continuous flow.