Highly Stereoselective Addition of β‐Borylenamides to Aldehydes Enabled by Late‑Stage Ligand Modification

Abstract

ABSTRACT The stereoselective synthesis of allylic alcohols bearing both a hydroxyl stereocenter and defined olefin geometry remains a significant challenge. While traditional methods predominantly furnish thermodynamically favored ( E )‐isomers, efficient access to enantiomerically enriched ( Z )‐configured counterparts is severely underdeveloped. Herein, we report an asymmetric addition of β‐borylenamides to aldehydes by rhodium catalysis, enabling the synthesis of ( Z )‐hydroxy enamides with excellent stereocontrol. The requisite β‐borylenamides are stereoconvergently prepared from mixed‐olefin starting materials through directed electrophilic C−H borylation. A key innovation lies in the development of late‑stage modified ligands, readily accessible via direct arylation of phosphoramidites. This modular strategy circumvents traditional de novo ligand synthesis, thereby significantly accelerating the discovery and optimization of privileged ligands. The resulting allylic alcohol products undergo smooth reduction to furnish γ‐amino alcohols with exceptional enantio‐ and diastereocontrol. The influence of the modified ligands on enantioselectivity was elucidated through density functional theory (DFT) calculations.