Nickel-Catalyzed Directed C6-Selective C-H Alkylation of 2-Pyridones with Dienes and Activated Alkenes.

A pyridine-directed, C6-selective nickel-catalyzed ring-contracting C-H alkylation of 2-pyridones with 1,5-cyclooctadiene (cod) has been developed. The reaction proceeds smoothly under external-ligand-free conditions and is accelerated uniquely by a K3PO4 base. Preliminary mechanistic investigations with deuterium-labeled substrates and related reactions with some alkenes are also disclosed.