Research Progress on the Catalytic Enantioselective Synthesis of Axially Chiral Allenes by Chiral Organocatalysts

Chiral allenes are important structural scaffolds found in many natural products and drugs, and in addition, they also serve as building blocks for many organic transformations. The conventional methods for preparing chiral allenes rely on the resolution of racemic allenes and the chirality transfer between non-racemic propargylic derivatives and nucleophilic reagents. In recent years, the synthesis of chiral allenes by asymmetric catalysis has been achieved fruitful results. Among them, enantioselective synthesis of chiral allenes with chiral organic catalysts is particularly prominent. In this paper, the research progress of enantioselective synthesis of chiral allenes catalyzed by chiral organic catalysts in recent years is reviewed, including various reaction systems and synthesis applications.