Enantioseparation of Sulfoxides and Nitriles by Inclusion Crystallization with Chiral Organic Salts Based on l‐Phenylalanine

Enantioselective inclusion of aromatic sulfoxides and nitriles was achieved in a host framework created by organic salts comprising achiral benzoic acids and a chiral primary amine (1a) derived from l‐phenylalanine. Tuning of the combined achiral acid component successfully changed the chiral recognition ability of the organic salts. The guest molecules were hydrogen‐bonded to form three‐component inclusion crystals, and the enantiomers of nitriles and sulfoxides were separated with high selectivity up to 92 and 98 % ee. As far as we know, this is the first example of the enantioseparation of non‐functionalized aromatic nitriles. Enantioseparation of nitriles (up to 92 % ee) and sulfoxides (up to 98 % ee) by inclusion crystallization with chiral organic salts of 4‐hydroxybenzoic acids and a chiral primary amine derived from l‐phenylalanine is described. This is the first example of the direct enantioseparation of aromatic nitriles without other functional groups.