Scheme 2.

Identification of suitable ligands for the β‐ and γ‐C(sp³)−H alkynylation of free carboxylic acids. Reactions were conducted on a 0.2 mmol scale. Yields were determined by ¹H NMR analysis of the crude reaction mixture using 1,3,5‐trimethoxybenzene as an internal standard. The mass balance of the reactions is fully accounted for by the product formed and unreacted starting material. No di‐ or tri‐substituted product was observed in any case during the optimization studies.