Positional isomerization of N-allyl compounds with a practical low-valent cobalt catalyst system.

A practical, (E)-stereoselective synthesis of enamides and N-alkenyl heterocycles via cobalt-catalyzed positional isomerization is reported. The catalytic system consists of commercially available and bench-stable reagents. This method represents the first cobalt-catalyzed positional isomerization of N-allyl imides, sulfonamides, and nitrogen heterocycles (indoles, carbazoles and pyrroles). Mechanistic studies suggest a cobalt-hydride-type pathway.