Asymmetric Hydroformylation of Aryl Vinyl Ethers to Chiral 2‐Aryloxypropanals: Access to Aryloxypropionic Acid Herbicide Precursors
Jianqiang Zheng, Lin‐Na Qi, Cai You, Guoliang Chen, Xiuxiu Li, Xumu ZhangABSTRACT
Enantiopure aryloxypropionic acid herbicides are of considerable importance in modern crop protection, creating a strong demand for efficient catalytic approaches to their synthesis. Herein, we report a Rh/( S , R )‐DTB‐YanPhos‐catalyzed asymmetric hydroformylation of readily available aryl vinyl ethers, affording chiral 2‐aryloxypropanals in up to 99% yield and 98% ee with excellent chemo‐, regio‐, and enantioselectivity. The protocol features broad substrate scope, high catalytic efficiency (TON up to 6300), and excellent catalyst robustness. Gram‐scale synthesis and efficient conversion of the aldehydes into optically enriched aryloxypropionic acid herbicides demonstrate the practical utility of this method, providing a straightforward catalytic route to valuable chiral herbicide intermediates and related building blocks.