Regioselective and Redox-Neutral Cp*Ir -Catalyzed Allylic C-H Alkynylation.

Herein, we report a Cp*Ir -catalyzed highly regioselective and redox-neutral protocol for the construction of 1,4-enynes from unactivated olefins and bromoalkynes via intermolecular allylic C-H alkynylation. The developed mild reaction conditions tolerate a broad range of common functional groups, even enabling selective alkynylation of allylic C-H bonds in the presence of other prominent directing groups. Mechanistic experiments including the isolation of a catalytically active Ir -allyl species support an intermolecular allylic C-H activation followed by an electrophilic alkynylation.