Planar-to-Planar Chirality Transfer in the Excited State. Enantiodifferentiating Photoisomerization of Cyclooctenes Sensitized by Planar-Chiral Paracyclophane

Photochemical planar-to-planar chirality transfer was effected by using (R)-[10] paracyclophane-12-carboxylates as a planar-chiral sensitizer and (Z)-cyclooctene and (Z,Z)-1,5-cyclooctadiene as prochiral substrates to give a planar-chiral (E)and (E,Z)-isomer in up to 44% and 87% enantiomeric excess, respectively, the latter of which being the highest ever reported for a sensitized photochirogenic reaction.