A convenient synthetic approach to highly hindered 3,3′-bis(2,4,6-tri-tert-butylphenyl)-BINOL-derived phosphoric acids

The direct arylation of optically pure 3,3′-difluoro-BINOL derivatives with (2,4,6-tri- tert -butylphenyl)magnesium bromide was developed to prepare highly hindered 3,3′-bis(2,4,6-tri- tert -butylphenyl)-BINOL-derived chiral phosphoric acids (CPAs).