The ruthenium-catalyzed reaction of aromatic ketones with arylboronic acid esters (arylboronates) gave the orthoarylation product. For this coupling reaction, a RuH2(CO)(PPh3)3 complex exhibited the highest catalytic activity among the complexes screened. Several aromatic ketones, for example, acetophenones, acetonaphthone, alpha-tetralone, and benzosuberone, can be used in this coupling reaction