Assisted by Hydrogen-Bond Donors: Cinchona Quaternary Salts as Privileged Chiral Catalysts for Phase-Transfer Reactions.

This short review is devoted to asymmetric phase-transfer reactions that employ hybrid ammonium Cinchona catalysts supported by possessing hydrogen-bond donor groups. We present recent advances utilizing this type of catalyst in the field of biphasic reaction systems. The main emphasis is placed on the advantages of additional functional groups present in the structure of the catalyst, such as hydroxy, amide, (thio)urea or squaramide. 1 Introduction 2 Phase-Transfer Hybrid Cinchona Catalysts with a Free Hydroxy Group 3 (Thio)urea Hybrid Cinchona Catalysts 4 Hybrid Amide-Based Catalysts Bearing a Cinchona Scaffold 5 Conclusions [ABSTRACT FROM AUTHOR]