Symmetry in Cascade Chirality-Transfer Processes: A Catalytic Atroposelective Direct Arylation Approach to BINOL Derivatives.

ABSTRACT: Herein we disclose a scalable organocatalytic direct arylation approach for the regio- and atroposelective synthesis of non-C2-symmetric 2,2'-dihydroxy-1,1'-binaphthalenes (BINOLs). In the presence of catalytic amounts of axially chiral phosphoric acids, phenols and naphthols are coupled with iminoquinones via a cascade process that involves sequential aminal formation, sigmatropic rearrangement, and rearomatization to afford enantiomerically enriched BINOL derivatives in good to excellent yields. Our studies suggest that the (local) symmetry of the initially formed aminal intermediate has a dramatic impact on the level of enantioinduction in the final product. Aminals with a plane of symmetry give rise to BINOL derivatives with significantly lower enantiomeric excess than unsymmetrical on

SUBMITTER: Wang JZ 

PROVIDER: S-EPMC5360188 | biostudies-literature | 2016 Apr

REPOSITORIES: biostudies-literature