Revisiting Polyfluoroarenes as Radical Acceptors: Radical C–F Bond Borylation of Polyfluoroarenes with N‑Heterocyclic Carbene Boranes and Synthesis of Borane-Containing Liquid Crystals

Polyfluoroarenes work as good radical acceptors in the thermal radical reaction with N-heterocyclic carbene boranes (NHC-boranes) in the presence of di-tert-butyl peroxide. In this reaction, a C–F bond of polyfluoroarenes is substituted with an NHC-boryl group to provide B-aryl NHC-borane derivatives. The developed synthetic method was applied to the synthesis of novel borane-containing liquid crystalline molecules having highly thermal stability.