Recent Advances in the Organocatalytic Enantioselective Synthesis of Functionalized β-Lactones.

This Focus Review highlights recent developments in the organocatalytic enantioselective synthesis of β-lactone derivatives. Owing to the importance of β-lactones as a heterocyclic motif that is present in a variety of natural products and biologically active molecules, several catalytic methods have been developed for the synthesis of these compounds in their enantiomerically pure form. Organocatalytic methods that employ N-heterocyclic carbenes (NHCs), cinchona alkaloids, isothioureas, 4-dimethylaminopyridine (DMAP) derivatives, and phosphines have allowed the highly enantioselective synthesis of β-lactones from cheap and readily available starting materials. Moreover, the inherent strain in the four-membered ring of β-lactones has also been utilized in further synthetic transformations, thus making β-lactones a versatile intermediate in organic synthesis.