Asymmetric Decarboxylative Allylic Alkylation of Acyclic Enol Carbonates
Catalytic Enantioselective Synthesis of Acyclic Quaternary Centers: Palladium-Catalyzed Decarboxylative Allylic Alkylation of Fully Substituted Acyclic Enol Carbonates.
J. Am. Chem. Soc. 2018;
17. September 2018 (online)
The authors present the first enantioselective palladium-catalyzed decarboxylative allylic alkylation of fully substituted non-cyclic enol carbonates. The reaction delivers the linear α-quaternary ketones in excellent yields. The phosphinooxazolidine ligand controls the stereoselectivity of the reaction regardless of the Z/E geometry of the enolate starting material.
This work outlines a general method to access linear α-quaternary ketones with high enantioselectivity. A dynamic kinetic resolution of the two Z/E geometries of the enolate starting material is postulated under optimal reaction conditions, which comprise the use of an electron-deficient phosphinooxazolidine ligand.