Quaternary Carbon Center Forming [3 + 2] Cyclization Reaction by Adjusting the Substituents of Substrates.

Herein, we describe a variety of chiral hybrid pyrroidine-indole polycyclic derivatives with quaternary and continuous chiral centers were synthesized in good yields with excellent stereoselectivities through an asymmetric, intermolecular, and formal [3 + 2] cyclization reaction catalyzed by a bifunctional catalyst. In addition, the selection of substituents of substrates is the key to success, and both the hydroxyl group and the trifluoromethyl group play essential roles in the reaction.

An Atropo-enantioselective Synthesis of Benzo-Linked Axially Chiral Indoles via Hydrogen-Bond Catalysis.

A variety of axially chiral biaryldiols were synthesized in good yields with excellent atropo-enantioselectivities through construction of axially chiral indoles catalyzed by asymmetric hydrogen-bond donors. In addition, the new axially chiral compounds were proved to be efficient and practical catalysts for asymmetric catalysis. The strategy not only provides a novel method to synthesize axially chiral compounds but also extends the scope of chiral catalysts.

Organocatalytic, Enantioselective Friedel-Crafts Reaction of Indoles in the Carbocyclic Ring and Electron-Rich Phenols.

An efficient method has been successfully developed to achieve the asymmetric C-H functionalization of indoles in the carbocyclic ring via organocatalysis, and a variety of tetrahydropyranoindoles were synthesized in good yields with excellent stereoselectivities. Further study on thermodynamic calculations indicated that the process was promoted by generating more thermodynamically stable products. This strategy, together with traditional C-3 functionalization of hydroxyindoles, could realize the switchable, regiodivergent asymmetric modification of indoles.