Design principles for enantiospecific para- and ortho-[3,3] rearrangements of chiral aryl–allyl ethers

Abstract

We report a systematic study that elucidates the regio-determining features of the stereoretentive para-Claisen–Cope and ortho-Claisen rearrangements of enantioenriched aryl–allyl ethers under mild catalytic conditions. The role of the aromatic substitution pattern as well as the nature of the rearranging ether moiety were thoroughly investigated, revealing that both para- and ortho-alkylation proceeded enantiospecifically with near-perfect chirality transfer. These findings resulted in rational design principles for accessing synthetically versatile, enantioenriched phenols and gave insights into how steric and electronic influences direct the [3,3]-rearrangements.