An Approach for Highly\nEnantioselective Synthesis\nof <i>meta</i>-Disubstituted [<i>n</i>]Paracyclophanes

Atroposelective\nsynthesis of <i>meta</i>-disubstituted\n[<i>n</i>]paracyclophanes is a difficult task in organic\nchemistry. We describe a facile approach for the synthesis of <i>meta</i>-disubstituted [<i>n</i>]paracyclophanes using\nPd-catalyzed enantioselective C–H olefination and sequential\nreductive cleavage. A wide range of [<i>n</i>]paracyclophanes\nwas obtained with excellent enantioselectivity. Thermodynamic analysis\nrevealed that the rotational barrier of <i>meta</i>-disubstituted\n[<i>n</i>]paracyclophanes was lower than that of <i>para</i>-disubstituted [<i>n</i>]paracyclophanes.\nThe synthesized planar-chiral [14]paracyclophane showed a bright fluorescence\nemission and impressive circularly polarized luminescence activity.