An Approach for Highly Enantioselective Synthesis of <i>meta</i>-Disubstituted [<i>n</i>]Paracyclophanes
Jia Li, Ziyang Dong, Hongxuan Zhai, Jicheng Wu, Changgui Zhao
Abstract
Atroposelective synthesis of meta -disubstituted [ n ]paracyclophanes is a difficult task in organic chemistry. We describe a facile approach for the synthesis of meta -disubstituted [ n ]paracyclophanes using Pd-catalyzed enantioselective C–H olefination and sequential reductive cleavage. A wide range of [ n ]paracyclophanes was obtained with excellent enantioselectivity. Thermodynamic analysis revealed that the rotational barrier of meta -disubstituted [ n ]paracyclophanes was lower than that of para -disubstituted [ n ]paracyclophanes. The synthesized planar-chiral [14]paracyclophane showed a bright fluorescence emission and impressive circularly polarized luminescence activity.