Palladium-Catalyzed Allylic Amidation with N‑Heterocycles via sp³ C–H Oxidation

An atom-economic direct intermolecular allylic amidation of electron-deficient tautomerizable N-heterocycles is reported via allylic C–H activation of terminal olefins with a PdCl2 catalyst. The reaction did not require any activators (base or Lewis acid) or external ligands and proceeded with high chemo- (N vs O), regio- (linear vs branched), and stereoselectivity (E vs Z) for a variety of N-heterocycles and terminal olefins. Mechanistic investigation and stoichiometric studies validate the sulfoxide-ligand-assisted allylic C–H bond cleavage to form a π-allylpalladium intermediate in the reaction pathway. Excellent selectivity was observed during intermolecular competition demonstrating the differential nucleophilicity of N-heterocycles and differential susceptibility of allyl C–H bond cleavage to form π-allylpalladium complexes directly from terminal olefins.