Hydrogenation of fluoroarenes: Direct access to all-cis-(multi)fluorinated cycloalkanes

Abstract

All-cis-multifluorinated cycloalkanes exhibit intriguing electronic properties. In particular, they display extremely high dipole moments perpendicular to the aliphatic ring, making them highly desired motifs in material science. Very few such motifs have been prepared, as their syntheses require multistep sequences from diastereoselectively prefunctionalized precursors. Herein we report a synthetic strategy to access these valuable materials via the rhodium-cyclic (alkyl)(amino)carbene (CAAC)-catalyzed hydrogenation of readily available fluorinated arenes in hexane. This route enables the scalable single-step preparation of an abundance of multisubstituted and multifluorinated cycloalkanes, including all-cis-1, 2, 3, 4, 5, 6-hexafluorocyclohexane as well as cis-configured fluorinated aliphatic heterocycles.