Enantioselective synthesis of triarylmethanes organocatalytic transfer hydrogenation of -quinone methides.

A new organocatalytic asymmetric method for the synthesis of enantioenriched triarylmethanes is developed. Different from the conventional approaches featuring asymmetric arylation, the present study employs asymmetric reduction C-H bond formation as the key step. This approach does not require the presence of a heteroaryl ring or the presynthesis of unstable -quinone methides. Instead, the stable racemic triarylmethanols were used as substrates for the generation of the intermediates with a suitable chiral phosphoric acid catalyst.