Non-Symmetrically Substituted 1,1‘-Binaphthyls in Enantioselective Catalysis

Axial chirality was predicted by van't Hoff in his historical paper, which laid the foundations of stereochemistry. BINOL (1), one of the best known representatives of axially chiral molecules, was first prepared as a racemate in 1873, and later as an optically active compound, whose absolute configuration was determined in 1971. In 1979, Noyor showed BINOL (1) to be a superb chiral ligand in the stoichiometric reduction of ketones with LiA1H4, giving corresponding alcohols in less than or equal to 99% ee.