Ruthenium-Catalyzed Ortho C-H Arylation of Aromatic Nitriles with Arylboronates and Observation of Partial Para Arylation

Ruthenium-catalyzed C-H arylation of aromatic nitriles with arylboronates is described. The use of RuH₂(CO){P(4-MeC₆H₄)₃}₃ as a catalyst provided higher yields of the ortho arylation products than the conventional RuH₂(CO)(PPh₃)₃ catalyst. The arylation takes place mostly at the ortho positions, but unprecedented para arylation was also partially observed to give ortho,para diarylation products. In addition to C-H bond cleavage, the cyano group was also found to function as a directing group for cleavage of C-O bonds in aryl ethers.