The Diaryliodonium(III) Salts Reaction With Free-Radicals Enables One-Pot Double Arylation of Naphthols

Abstract

The chemoselective reaction of the C- followed by the O-centered naphthyl radicals with the more electron-deficient hypervalent bond of the diaryliodonium(III) salts is described. This discovered reactivity constitutes a new activation mode of the diaryliodonium(III) salts which enabled a one-pot doubly arylation of naphthols through the sequential ${\text{C}}_{sp}^2$ - ${\text{C}}_{sp}^2$ /O- ${\text{C}}_{sp}^2$ bond formation. The naphthyl radicals were generated in the reaction by the tetramethylpiperidinyl radical (TMP·) which resulted from the homolytic fragmentation of the precursor TMP₂O. Experimental and DFT calculations provided a complete panorama of the reaction mechanism.

Keywords: diaryliodonium(III) salts; double arylation; electron-deficient hypervalent bond; one-pot double arylation; reaction with free-radicals.