Chromium‐Catalyzed Stereodivergent Carbonyl Addition Dictated by Non‐Covalent Interactions

ABSTRACT

Catalytic stereodivergent synthesis, which accesses the full complement of stereoisomers from a common precursor set, is a paramount objective in drug discovery. However, achieving this control via radical‐involved pathways remains a formidable frontier due to the transient nature of open‐shell intermediates. Here, we report a unified chromium‐catalyzed platform that harnesses a radical–polar crossover mechanism to achieve the fully ligand‐controlled stereodivergent synthesis of chiral β ‐fluoro alcohols. We demonstrate that the stereochemical outcome is not inherent to the substrate but is dictated by the ancillary ligand through distinct non‐covalent interactions: a chiral bisoxazoline ligand enforces a rigid transition state via fluorine‐mediated hydrogen bonding to selectively deliver syn ‐diastereomers, whereas a chemically distinct pyridine–imidazoline ligand exploits electronic desymmetrization via π–π stacking to invert selectivity toward anti ‐isomers. Notably, this protocol enables the programmable assembly of all four stereoisomers of fluorosugar derivatives.