A new method for optical resolution of BINOL by molecular complexation with (S)-5-oxopyrrolidine-2-carboxanilide

A new method for optical resolution of racemic 1,1′-bi-2-naphthol (BINOL) has been developed through molecular complexation with a cheap and readily accessible (S)-5-oxopyrrolidine-2-carboxanilide, affording the enantioenriched BINOL in up to 70.4% ee and 73.6% yield. X-Ray structural analysis of a molecular crystal formed between (R)-BINOL and (S)-5-oxopyrrolidine-2-carboxanilide indicates that the hydrogen bonding interactions between the carbonyl groups of amides and the hydroxyl groups of (R)-BINOL predominate in the molecular complex formation. The chiral features of the amide and the complementary molecular packing in the crystal lattice control the stereochemistry of the guest in the molecular crystal.