Merging photoredox catalysis with allylboration. The photochemical perfluoroalkylation of unsaturated potassium alkyltrifluoroborates and synthesis of fluorinated alcohols

Abstract

The development of a visible light-mediated atom transfer radical addition (ATRA) of perfluoroalkyl iodides to potassium 1-penten-5-yl-, vinyl- and allyltrifluoroborates using the reductive quenching of [Ru(bpy)3]Cl2 or [Ru(bpy)3](PF6)2 is described. Using an operationally simple and mild protocol, the corresponding potassium trifluoroborates containing perfluoroalkyl groups were obtained in moderate to high yields. In the case of potassium allyltrifluoroborate, the use of acetone as the solvent resulted in allylboration followed by ATRA of perfluoroalkyl iodides to the formed homoallyl alcohol. A one-pot protocol was developed for the synthesis of a series of fluorinated alcohols using potassium allyltrifluoroborate, perfluoroalkyl iodides and selected aliphatic ketones.