Direct Superacid-Promoted Difluoroethylation of Aromatics

Under superacid conditions, aromatic amines are directly and regioselectively 1,1-difluoroethylated. Low temperature in situ NMR studies confirmed the presence of benzylic alpha-fluoronium and alpha-chloronium ions as key intermediates in the reaction. This method has a wide substrate scope and can be applied to the late-stage functionalization of natural alkaloids and active pharmaceutical ingredients.

Automated summary

Under superacid conditions, aromatic amines can undergo direct and regioselective 1,1-difluoroethylation. In situ NMR studies at low temperatures confirmed the presence of key intermediates such as benzylic alpha-fluoronium and alpha-chloronium ions in the reaction. This method has a broad substrate scope and can be applied to the late-stage functionalization of natural alkaloids and active pharmaceutical ingredients.