Sterically Demanding, Bioxazoline-Derived N-Heterocyclic Carbene Ligands with Restricted Flexibility for Catalysis

A unique family of N-heterocyclic carbenes derived from bioxazolines (IBiox) suitable for
application in transition-metal catalysis is described. The ligands are electron rich, sterically demanding,
and have restricted flexibility. Their usefulness has been demonstrated in the Suzuki−Miyaura cross-coupling
of sterically hindered aryl chlorides and boronic acids. For the first time, tetraortho-substituted biaryls with
methyl and larger ortho-substituents have been synthesized from aryl chlorides using the Suzuki−Miyaura
method.