Cu-Catalyzed Enantioselective Ring Opening of Cyclic Diaryliodoniums toward the Synthesis of Chiral Diarylmethanes.

A Cu-catalyzed enantioselective desymmetrizing ring-opening reaction of six-membered cyclic diaryliodonium salts with carboxylic acids or thioacids is reported for the facile access to chiral diarylmethanes. A Cu/[cyclopropyl bis(oxazoline)] catalyst well discriminates two C-I bonds of prochiral cyclic diaryliodonium salts. A stereochemical model was proposed to rationalize the stereochemical outcome on the basis of the crystal structure of cyclic diaryliodonium salt.