New Types of Planar Chiral [2.2]Paracyclophanes and Construction of One-Handed Double Helices.

New types of planar chiral (Rp )- and (Sp )-4,7,12,15-tetrasubstituted [2.2]paracyclophanes were synthesized from racemic 4,12-dihydroxy[2.2]paracyclophane as the starting compound. Regioselective dibromination and transformation afforded a series of planar chiral (Rp )- and (Sp )-4,7,12,15-tetrasubstituted [2.2]paracyclophanes, which can be used as chiral building blocks. In this study, left- and right-handed double helical structures were constructed via chemoselective Sonogashira-Hagihara coupling. The double helical compounds were excellent circularly polarized luminescence (CPL) emitters with large molar extinction coefficients, good photoluminescence quantum efficiencies, and large CPL dissymmetry factors.