Photoredox Catalyzed Dealkylative Aromatic Halogen Substitution with Tertiary Amines

Abstract

A reaction of aromatic halides bearing electron-withdrawing groups with tertiary amines in the presence of an iridium catalyst under blue light irradiation is described. Products of the aromatic substitution of the halide by the dialkylamino fragment are obtained. The interaction of aryl radicals with tertiary amines to generate zwitterionic radical species is believed to be the key factor responsible for the reaction efficiency.

Radical reactions enabled by polyfluoroaryl fragments: photocatalysis and beyond

“…It turns out that the use of tertiary aliphatic amines less hindered than DIPEA allows reactions to be carried out in the direction of C–N bond formation. 67 According to the proposed mechanism, the perfluoroaryl radical attacks a neutral amine, after which the zwitterion is oxidized by photocatalyst to an ammonium salt followed by classical polar dealkylation by the second amine molecule. It should be noted that this reaction is not limited to polyfluoroarenes and also proceeds with other electron-deficient aryl halides.…”

Perfluoropyridine: Discovery, Chemistry, and Applications in Polymers and Material Science

“…Since its initial reported synthesis in the early 1960s, there have been over 600 publications in which PFPy has been utilized as a starting material or reagent [ 35 ]. With that, the chemical transformations of PFPy are well documented and some noteworthy methodologies include C-F bond activation [ 36 ], photoredox reactions [ 37 , 38 ], hydrodefluorination [ 39 , 40 ], and nucleophilic addition [ 41 ]. With the variety of readily available nucleophiles, the latter of these known chemical transformations has shown to be quite versatile.…”