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.
- Amide base
- Homolytic aromatic substitution
ASJC Scopus subject areas
- Organic Chemistry