Isoprene: A Promising Coupling Partner in C–H Functionalizations

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.

Advances in Transition Metal-Catalyzed C(sp2)-H Bond Functionalization Using Allyl Alcohols

The transition metal-catalyzed directed site-selective C─H bond functionalization utilizing allyl alcohols as coupling partner has been an intriguing area of research and has made considerable advances during the past decade. Multifunctional coupling characteristics of the allyl alcohol in the regioselective C(sp2)-H functionalization using transition metal-catalysis produces alkyl, alkenyl, allyl, and annulated products. These reactions provide an effective synthetic tool to afford diverse functionalized scaffolds that are of interest in synthetic and medicinal sciences. This review covers the developments of directed site-selective C(sp2)-H functionalization with unactivated allyl alcohols as the coupling partner using the transition metal-catalysis till December, 2024.