AlCl3-Meditated 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.

Automated summary

In this study, a transition-metal-free frustrated Lewis pair (FLP) catalyzed reaction was reported for the first time, enabling the migration of CHF2 group from an oxygen atom to the neighboring nitrogen atom. The reaction resulted in the synthesis of N-substituted benzimidazoles at room temperature, with excellent yields, broad functional group tolerance, and a short reaction time.