Copper-Catalyzed Enantioselective Ring-Opening of Cyclic Diaryliodoniums and O-Alkylhydroxylamines

Abstract

A preparation of 2-hydroxyamino-2'-iodobiaryls via the Cu-catalyzed enantioselective ring-opening reaction of cyclic diaryliodonium salts with O-alkylhydroxylamines is reported. 3,5-Di(tert-butyl)phenyl bis(oxazoline) was found to be the optimal ligand, and up to 99% ee values were achieved. The use of CaO as the base dramatically improved the yields and inhibited the side reactions. Finally, synthetic applications of these hydroxylamines were briefly demonstrated.