Fluoroanalogs of DDT: Superacidic BF3-H2O Catalyzed Facile Synthesis of 1,1,1-Trifluoro-2,2-diarylethanes and 1,1-Difluoro-2,2-diarylethanes

The one-pot synthesis of 1,1,1-trifluoro- and 1,1-difluoro-2,2-diarylethanes from arenes and fluorinated hemiacetals in the BF3-H2O system is described. The reaction is simple, clean, and convenient, eliminating the use of organic solvents and other expensive acid systems. BF3-H2O is economic, is easy to prepare, and offers ample acidity required for this reaction.