Pd-catalyzed asymmetric carbonyl alkynylation: Synthesis of axial chiral ynones

Abstract

Ynones are important skeletons in bioactive molecules and valuable building blocks for organic synthesis, thus great efforts have been devoted to their preparation. While, introducing prochiral substrates to construct ynones bearing a chiral framework is unrealized to date. Herein, we reported the first example of Pd/SOP-catalyzed asymmetric carbonylative alkynylation via a non-classical carbonylative Sonogashira-type approach (acyl-Pd(II) species generated from nucleophiles). By using cyclic diaryliodonium salts as prochiral substrates, various axial chiral ynones with good functional group tolerance (39 examples), satisfied yields (71%-96%) and excellent enantioselectivities (generally 94%-99% ee) were produced. Synthesis of bioactive compounds, scale-up experiment and useful transformations were also conducted to demonstrate the utility of this process.