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

## TL;DR

This paper explains how to control the direction of chemical rearrangements to produce specific chiral products with high purity.

## Contribution

The study establishes design principles for enantiospecific para- and ortho-Claisen rearrangements of chiral aryl–allyl ethers.

## Key findings

- Both para- and ortho-alkylation proceed enantiospecifically with near-perfect chirality transfer.
- Steric and electronic influences were identified as key factors directing the [3,3]-rearrangements.

## 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.

Regioselective allyl–aryl rearrangements directed by substituents yield chiral ortho- and para-alkylated products in high enantiomeric purity.