Synthesis and application of novel biaryl compounds with axial chirality as catalysts in enantioselective reactions

Abstract

A highly efficient process of aerobic oxidative coupling of 2-naphthol derivatives catalyzed by Cu(OH)Cl.TMEDA has been developed. Enantioselective oxidative coupling of 2-naphthol derivatives was achieved by the use of a chiral catalyst prepared from proline-derived diamine and cuprous chloride, affording the corresponding BINOL derivatives in good enantioselectivities of up to 78% ee. A new catalytic, enantioselective allylation of aldehydes with allyltrichlorosilanes exploiting (S)-3,3'-dimethyl-2,2'-biquinoline N,N'-dioxide as a catalyst affords homoallylic alcohols in virtually complete diastereoselectivities and high enantioselectivities of up to 92% ee, wherein the use of diisopropylethylamine as an additive has proven to be crucial for the acceleration of the catalytic cycle. It is also noteworthy that the above finding represents the first successful example of asymmetric reactions utilizing amine N-oxide as a chiral catalyst.