Photochirogenesis in chiral ionic liquid: Enantiodifferentiating [4+4] photocyclodimerization of 2-anthracenecarboxylic acid in (R)-1-methyl-3-(2,3-dihydroxypropyl)imidazolium bistriflimide

Enantiodifferentiating photocyclodimerization of 2-anthracenecarboxylic acid and its alkali metal salts performed in a chiral ionic liquid gave chiral cyclodimers in good enantiomeric excesses of up to 41%, which is the highest ever reported for a photochirogenic reaction in chiral media.