Catalytic Asymmetric Construction of ,-Diaryl Aldehydes via Oxo-Hydroarylation of Terminal Alkynes

Chiral aldehydes containing a tertiary stereogenic center are versatile building blocks in organic chemistry. In particular, such structural motifs bearing an alpha,alpha-diaryl moiety are very challenging scaffolds and their efficient asymmetric synthesis is not reported. In this work, a phosphoric acid-catalyzed enantioselective synthesis of alpha,alpha-diaryl aldehydes from simple terminal alkynes is presented. This approach yields a wide range of highly enolizable alpha,alpha-diaryl aldehydes in good yields with excellent enantioselectivities. Facile transformations of the products, as well as an efficient synthesis of bioactive molecules, including an effective anti-smallpox agent and an FDA-approved antidepressant drug (+)-sertraline, are demonstrated.