Mild and Efficient Ir(III)-Catalyzed Direct C–H Alkynylation of N-Phenoxyacetamides with Terminal Alkyne

Ir(III)-catalyzed direct C–H alkynylation of arenes has been developed using commercially available TIPS-acetylene as an efficient alkynylating reagent, where O-NHAc was employed as an autocleavable oxidizing-directing group (ODG auto ), thus giving rise to ortho -alkynylated phenols under mild reaction conditions in a highly efficient and redox-neutral manner. The reaction proceeded with high regioselectivity and broad substrate/functional group (FG) tolerance. The synthetic application of the products has been briefly exemplified. Preliminary mechanistic studies have been conducted, and a five-membered iridacycle has also been identified as a key intermediate.