Catalytic C-H Bond Addition of Pyridines to Allenes by a Rare-Earth Catalyst

摘要

The catalytic CH addition of pyridines to allenes has been achieved for the first time by using a half-sandwich scandium catalyst, thus constituting a straightforward and atom-economical route for the synthesis of alkenylated pyridine derivatives. The reaction proceeded regio- and stereoselectively, affording a new family of alkenylated pyridine compounds which are otherwise difficult to synthesize. A cationic Sc-(2)-pyridyl species was isolated and confirmed to be a key catalyst species in this transformation.