2-(o-Tolyl) Pyridine as Ligand Improves the Efficiency in Ketone Directed ortho-Arylation

Herein, we report a ruthenium-catalyzed ketone directed ortho-arylation wherein the addition of a bidentate NC-type ligand, most effectively 2-(o-tolyl) pyridine, significantly enhances the C-H arylation reaction. Various aryl-alkyl ketones, including cyclic, aliphatic, and heterocyclic ones, are competent substrates, and arylboronic acid esters were used as aryl sources. However, substitution with OMe and CF3 in the aromatic ring of the ketone substrates is not tolerated, while such residues on the benzoic ester are possible. Notably, this study provides valuable insights into ketone-directed ortho arylation in the presence of 2-(o-tolyl) pyridine and adds additional options for catalyst and ligand optimization in ruthenium-catalyzed C-H functionalization.

Automated summary

Here, a ruthenium-catalyzed ketone directed ortho-arylation is described, in which the addition of a bidentate NC-type ligand, particularly 2-(o-tolyl) pyridine, significantly enhances the C-H arylation reaction. Various aryl-alkyl ketones are competent substrates, and arylboronic acid esters are used as aryl sources. However, substitution with OMe and CF3 in the aromatic ring of the ketone substrates is not tolerated.