Highly Enantioselective [5 + 2] Annulations through Cooperative N-Heterocyclic Carbene (NHC) Organocatalysis and Palladium Catalysis

J Am Chem Soc. 2018 Mar 14;140(10):3551-3554. doi: 10.1021/jacs.8b00868. Epub 2018 Feb 28.

Abstract

The highly enantioselective [5 + 2] annulation of enals with vinylethylene carbonates through a cooperative N-heterocyclic carbene (NHC)/Pd catalytic system is reported. The use of a bidentate phosphine ligand was crucial to prevent coordination of the NHC organocatalyst to the active Pd catalyst. The complementary and matched combination of the chiral NHC catalyst and chiral phosphine ligand promotes high levels of both reactivity and enantioselectivity (mostly ≥99% ee).

Publication types

  • Research Support, Non-U.S. Gov't