Efficient Catalytic System for Ru-Catalyzed C-H Arylation and Application to a Practical Synthesis of a Pharmaceutical

A series of K salts of sulfonic acids have been tested as a cocatalyst for Ru-catalyzed CH arylation. Among them, K 2, 4, 6-trimethylbenzenesulfonate (TMBSK) was found to be most active, and generality of the reaction was confirmed for a variety of nitrogen-containing heterocycles to give corresponding functionalized biaryls in high yields. The present methodology was applied to a practical synthesis of Candesartan Cilexetil