Ruthenium-catalyzed olefinic C–H alkenylation of enol-carbamates: highly stereo-selective synthesis of (Z,Z) and (Z,E)-butadienes†
Abstract
Cross-coupling reactions of enol carbamates with alkynes or alkenes are reported, using an inexpensive ruthenium catalyst. With the assistance of the directing group OCONMe2, the protocols provide mild, stereo-selective and efficient routes for the preparation of valuable (Z,Z) and (Z,E)-butadiene skeletons.