Cross-Coupling of Nitroalkanes with Enamides, Enecarbamates, and Enol Ethers

A stepwise cross-coupling of cyclic enamides, enecarbamates, and enol ethers, with functionalized nitroalkanes has been developed, offering access to functionalized tetrahydropyridines, dihydropyrans, and other heterocycles. The outcome of the palladium-free process resembles a Heck-type reaction, in which β-substituted nitroalkanes serve as an acrylate surrogate. The method utilizing the powerful CAN oxidant tolerates several commonly employed protective groups and operates via a well-understood reaction mechanism.