Kinetic resolution of substituted amido[2.2]paracyclophanes via asymmetric electrophilic amination.

Planar chiral [2.2]paracyclophane derivatives are a type of structurally intriguing and practically useful chiral molecules, which have found a range of important applications in the field of asymmetric catalysis and material science. However, access to enantioenriched [2.2]paracyclophanes represents a longstanding challenge in organic synthesis due to their unique structures, which are still highly dependent on the chiral chromatography separation technique and classical chemical resolution strategy to date. In this work, we report on an efficient and versatile kinetic resolution protocol for various substituted amido[2.2]paracyclophanes, including those with pseudo-geminal, pseudo-ortho, pseudo-meta and pseudo-para disubstitutions, using chiral phosphoric acid (CPA)-catalyzed asymmetric amination reaction, which was also applicable to the enantioselective desymmetrization of an achiral diamido[2.2]paracyclophane. Detailed experimental studies shed light on a new reaction mechanism for the electrophilic aromatic C-H amination, which proceeded through sequential triazane formation and N[1,5]-rearrangement. The facile large-scale kinetic resolution reaction and diverse derivatizations of both the recovered chiral starting materials and the C-H amination products showcased the potential of this method.

Asymmetric synthesis of planar-chiral macrocycles via organocatalyzed enantioselective macrocyclization.

A novel enantioselective macrocyclization method has been developed for the asymmetric synthesis of planar-chiral macrocycles through chiral phosphoric acid-catalyzed intramolecular addition of the hydroxy group with the allenamide moiety. A series of planar-chiral macrocycles bearing various ring sizes (18-member to 22-member) and various functional groups were generated with good to high enantioselectivities.