Desymmetrization/Kinetic Resolution of Planar Chiral [2.2]Paracyclophanes by Bioinspired Peptide-Iminophosphorane Catalysis

Abstract

Planar chiral [2.2]paracyclophanes, particularly pseudo-disubstituted derivatives, are privileged scaffolds for chiral ligands and catalysts in asymmetric synthesis and have widespread applications in materials science. However, catalytic asymmetric approaches for the enantioselective synthesis of pseudo-disubstituted [2.2]paracyclophanes remain underexplored. In this study, we introduce a novel class of peptide-iminophosphorane organosuperbases to induce planar chirality in spatially stacked [2.2]paracyclophanes. This efficient protocol enables the enantioselective synthesis of a diverse array of structurally distinct pseudo-gem, pseudo-ortho, and pseudo-para [2.2]paracyclophanes, achieving high yields and excellent enantioselectivities via desymmetrization or kinetic resolution. Moreover, the products can be readily diversified through various functional group transformations. Mechanistic investigations provide valuable insights into the unique stereocontrol exhibited by this peptide-iminophosphorane catalytic system.