Application of sulfonium and sulfoxonium ylides in organocatalyzed asymmetric reaction

Sulfur-based ylides are very important and valuable reagents in organic synthesis and have been widely applied in the preparation of cyclic compounds and the formation of C-X (X = C, N, O, S, B, P) bond. Since the early 2000s, asymmetric organocatalysis has become a powerful strategy in organic synthesis (even highlighted by the 2021 Nobel Prize in Chemistry) and has attracted widespread research interest among synthetic organic chemists. In this area, a large number of outstanding achievements have been registered in the novel chiral catalysts design, new compounds synthesis, various reagents application, and versatile reaction discovery. Given the extensive application of sulfonium and sulfoxonium ylides in organic synthesis, in this review, we mainly summarize the organocatalyzed asymmetric reactions involving these ylide reagents as one of the reactants. Detailed reaction mechanisms, transition states and some synthetic applications are highlighted. The challenges and opportunities of this field are also discussed in the outlook.