Organocatalytic Diversity-Oriented Asymmetric Synthesis of Structurally and Stereochemically Complex Heterocycles.

An asymmetric organocatalytic direct arylation approach to construct arylated quaternary stereogenic centers with a catalyst loading of 1 mol % is reported. The formation of the hemiketal moiety in stabilizing the hydroquinone intermediate proves to be important in leading to hydroquinone products instead of oxidation quinone products obtained in previously reported methods. A series of structurally and stereochemically complex heterocyclic frameworks are obtained, including spiro-, dispiro-, fused, and bridged heterocycles.