Enantioselective halogenation via asymmetric phase-transfer catalysis

Abstract

Chiral phase-transfer catalyst brings insoluble ionic halogenating reagents into the solution and mediates enantioselective halogenations by forming highly ordered asymmetric environments through ion pairing and/or hydrogen-bonding interactions with the substrate and the reagent. Such approaches have been enormously successful in both nucleophilic and electrophilic halogenations. In this review, the remarkable examples over the past decade are surveyed with brief mechanistic discussions.