Enantioselective γ-borylation of unsaturated amides and stereoretentive Suzuki-Miyaura cross-coupling

The rhodium-catalyzed, directed catalytic asymmetric hydroboration of gamma,delta-unsaturated amides affords a direct route to chiral acyclic secondary gamma-borylated carbonyl derivatives in high enantiomeric purity. In contrast to a similar beta-borylated amide derivative, the gamma-borylated amide undergoes Suzuki-Miyaura cross-coupling with stereoretention. The utility of the boronic ester products is further illustrated by other stereospecific C-B bond transformations leading to gamma-amino acid derivatives, 1,4-amino alcohols, and 5-substituted-gamma-lactone and gamma-lactam ring systems.