Evaluation of Electron‐Deficient Phosphine Ligands for Direct Arylation of Heterocycles

New electron‐deficient biarylphosphine ligands were studied and proved to be efficient for the direct arylation of heteroarenes with aryl iodides. The ability of a more electron‐deficient palladium centre to accelerate the arylation of heterocycles that remained unreactive with aryl iodides in the past has been validated and these heteroarenes can now be smoothly reacted in the presence of a new electrophilic catalyst. Experimental evidence suggests a viable concerted metalation–deprotonation pathway for the CH bond cleavage step with an electron‐deficient palladium centre.