Construction of Biaryl Scaffolds from Iodoarenes and C−H Heteroarenes Using an Amide Base Generated in situ from Aminosilane and Fluoride Anion

Iodoarenes and C−H heteroarenes are coupled to form a biaryl in the presence of an amide base generated in situ from tetramethylammonium fluoride (TMAF) and hexamethyldisilazane (HMDS) by homolytic aromatic substitution (HAS). This reaction can be used with electron‐rich, ‐deficient, and ortho‐substituted haloarenes. Both electron‐rich and ‐deficient C−H heteroarenes can also be utilized. Involvement of a radical intermediate was confirmed by radical inhibition experiments, deuterium‐labelling experiments, and EPR spectral measurements. Enhancement of the reactivity of electron‐rich N‐methylpyrrole was observed in the presence of electron‐poor phenazine or pyrazine. Iodoarenes and C−H heteroarenes form biaryls by an amide base generated in situ from aminosilanes and fluoride anions through homolytic aromatic substitution. This reaction can be used with electron‐rich and electron‐deficient haloarenes. Involvement of a radical intermediate was confirmed by radical‐inhibition, deuterium‐labelling experiments, and EPR measurements. The reactivity of electron‐rich N‐methylpyrrole was enhanced by electron‐poor phenazine.