Organocatalytic enantioselective conjugate addition of 2-naphthols to ortho-hydroxyphenyl substituted para-quinone methides: access to unsymmetrical triarylmethanes

The enantioselective conjugate addition of 2-naphthols to ortho-hydroxyphenyl substituted para-quinone methides has been achieved with the aid of a chiral phosphoric acid. Importantly, the reaction took place with excellent chemo- and regioselectivities. In addition, the protocol features a low catalyst loading, mild reaction conditions, and enables the formation of unsymmetrical triarylmethanes in good to high yields with generally high enantioselectivities.