Multiple arylation of carbonyl compounds via palladium catalysis

The palladium catalyzed direct arylation of carbonyl compounds using aryl halides has recently been developed. While most of works for the reaction focused on monoarylation at α-position of the carbonyl group, we succeeded in performing the introduction of several aryl groups to the substrates by single treatment. Thus, for example, in the presence of excess of aryl halides acetophenone undergoes arylation not only on the α-position, but also on the ortho-position to produce tetraarylated products. In this short account are summarized our recent results for multiple arylation of a number of ketones, amides, and α,β-unsaturated carbonyl compounds.