Site-Selective Pd-Catalyzed C(sp3)-H Arylation of Heteroaromatic Ketones.Chemistry. 2021 Dec 15; 27(70):17688-17694.C
A ligand-controlled site-selective C(sp3)-H arylation of heteroaromatic ketones has been developed using Pd catalysis. The reaction occurred selectively at the α- or β-position of the ketone side-chain. The switch from α- to β-arylation was realized by addition of a pyridone ligand. The α-arylation process showed broad scope and high site- and chemoselectivity, whereas the β-arylation was more limited. Mechanistic investigations suggested that α-arylation occurs through C-H activation/oxidative addition/reductive elimination whereas β-arylation involves desaturation and aryl insertion.