Asymmetric Organocatalytic Reactions of Activated Racemic Allenes

Asymmetric organocatalytic reactions of various electron-deficient racemic allenes with a wide variety of nucleophiles and electrophiles were reviewed. The literature on enantioselective functionalization of allenes that employs chiral phosphine, amine, phase transfer, bifunctional, and Brønsted acid catalysis is presented along with the mechanisms. In addition, the review emphasizes methods of obtaining enantioenriched allenes from racemic allenes via organocatalytic (dynamic) kinetic resolution techniques. The synthetic utility of the developed methodologies toward the target-orientated biologically active molecules is narrated along with the examples.