Co(III)-Catalyzed Three-Component Assembling of 2-Pyridones with Dienes and Formaldehyde via C-H Bond Activation.

Here, we have demonstrated a Co(III)-catalyzed C-H functionalization of substituted pyridones with dienes and para-formaldehyde via a three-component sequential reaction. A library of homoallylic alcohols is synthesized with high regio- and chemoselectivity. The reaction scope is widely compatible with various substituted N-pyridyl-2-pyridones, butadiene, and substituted dienes. Interestingly, N-pyridyl-4-pyridone also participated in the reaction. The synthesized product was further converted into dihydrofuran-derived N-pyridyl-2-pyridone derivatives. A convincing mechanism and mechanistic investigations are described to justify the current methodology.