AlCl3-Mediated CHF2 Transfer and Cyclocondensation of Difluoromethoxy Functionalized o-Phenylenediamines to Access N-Substituted Benzimidazoles.

Herein, we report for the first time a transition-metal-free frustrated Lewis pair (FLP) catalyzed CHF2 group migration from an oxygen atom to the neighboring nitrogen atom, which led to the synthesis of N-substituted benzimidazoles at room temperature with excellent yields, broad functional group tolerance, and a short reaction time. The oxygen-attached difluoromethane acted as a C1 source in the synthesis of N-substituted benzimidazoles in the presence of AlCl3 by cleaving one C-O bond and two C-F bonds, resulting in formation of two new C-N bonds.