Enantioselective Palladium-Catalyzed Desymmetric Allenylic Substitution of Allenylic Cyclic Carbonates: Access to Axially Chiral Trisubstituted α-Allenols.

An enantioselective palladium-catalyzed desymmetric allenylic substitution of novel allenylic cyclic carbonates with a variety of nucleophiles, including N-heterocyclic aromatics, secondary aliphatic amines, and bis(phenylsulfonyl)methane, under mild reaction conditions was developed, enabling challenging axially chiral trisubstituted α-allenols to be accessed in good to excellent yields with high enantioselectivities. The synthetic utility of this method is demonstrated through scalable reactions, axial-to-central chirality transfer, late-stage modification of drug molecules, and preliminary applications in chiral fluorescent probes and asymmetric catalysis. This study establishes π-alkadienylpalladium dipoles as versatile intermediates for asymmetric allenylic substitution and provides a new strategy for expanding the chemical space of axially chiral α-allenols.