Microwave‐Promoted <i>ortho</i>‐C−H Bond (Hetero)arylation of Arylpyrimidines in Water Catalyzed by Ruthenium(II)−Carboxylate

Abstract

Abstract Efficient diarylation of ortho ‐C−H bonds of 2‐arylpyrimidines was achieved by Ru(II)−carboxylate‐catalyzed reaction with aryl bromides in water, whereas meta ‐substituted phenylpyrimidines selectively led to monoarylation. The reaction is strongly accelerated under microwave irradiation, and is compatible with various functional groups on both coupling partners. As established from Hammett plots, electron‐withdrawing groups on the pyrimidine substrates facilitate the arylation, while both, electron‐withdrawing and electron‐donating groups on the aryl bromides lead to a faster reaction. The C−H functionalization of 2‐arylpyrimidines with heteroaryl halides provides potential multidentate ligands.