Directing-Group-Based Strategy Enabling Intermolecular Heck-Type Reaction of Cycloketone Oxime Esters and Unactivated Alkenes.

A new type of coupling between unactivated olefins and nonstabilized alkyl radicals was achieved, which enabled the first intermolecular Heck-type reaction of cycloketone oxime esters and unactivated alkenes. This directing-group-based strategy was compatible with various unactivated alkenes and cyclobutanone-, cyclopentanone-, and cyclohexanone-derived oxime esters. Density functional theory calculations showed that both excellent regioselectivities and good diastereoselectivities could be ascribed to the 2-butanol-assisted concerted H-OBz elimination of the conformationally strained metallacyclic transition state.