Enantioselective Synthesis of Planar Chiral [2.2]Paracyclophanes via Copper(I)-Catalyzed Desymmetrization: Access to Chiral 1,2,3-Triazoles

Abstract

Chiral 1,2,3-triazoles have emerged as valuable structural motifs in both drug discovery and materials science. Nevertheless, the catalytic asymmetric synthesis of such frameworks remains a significant challenge, primarily due to the inherent difficulty in achieving stereo control during the rapid click reaction, as well as the limited availability of broadly applicable efficient catalytic systems. Current methodologies largely focus on the synthesis of centrally or axially chiral molecules, with relatively few reports on enantioselective Cu(I)-catalyzed azide alkyne cycloadditions for the construction of planar chiral compounds. In this work, we report an efficient and broadly applicable strategy for the enantioselective synthesis of planar chiral [2.2]paracyclophanes (PCPs) employing Cu(I)-catalyzed desymmetrization. The method affords planar chiral 1,2,3-triazoles in high yields (up to 94%) and excellent enantioselectivities (up to 99%). Notably, this protocol enables the streamline efficient construction of diverse planar chiral triazoles bearing drug-like scaffolds under mild conditions and with broad functional group tolerance. Mechanistic investigations were conducted to elucidate the reaction pathway and the origin of enantioselectivity.