Stereodefined Skipped Dienes through Iridium-Catalyzed Formal Addition of Tertiary Allylic C-H Bonds to Alkynes.

Preparation of skipped dienes with a quaternary carbon center at the C-3 position remains a synthetic challenge. We report here an iridium-catalyzed formal addition of tertiary sp 3 C-H bond to alkyne for the facile preparation of skipped dienes. The tertiary allylic C-H bond is cleaved regioselectively, at the site of which a new C-C bond is formed. Enantioselective construction of acyclic quaternary carbon stereocenters is also demonstrated.