Recent Progress in Chiral Quaternary Ammonium Salt-Promoted Asymmetric Nucleophilic Additions

Chiral quaternary ammonium ion-pair organocatalysis has been widely used in the facile synthesis of chiral molecules with challenging stereocenters. Especially, numerous asymmetric nucleophilic addition reactions have been facilitated with this strategy. This review systematically summarizes the asymmetric nucleophilic additions promoted by chiral quaternary ammonium salts in the past decade. The content is organized according to the types of electrophiles involved in these catalytic transformations. Our own perspectives on future development within this highly active research field are also provided.