Stereoinvertive C-C Bond Formation at the Boron-Bound Stereogenic Centers through Copper-Bipyridine-Catalyzed Intramolecular Coupling of α-Aminobenzylboronic Esters.

Enantiospecific intramolecular Suzuki-Miyaura-type coupling with α-(2-halobenzoylamino)benzylboronic esters to give 3-substituted isoindolinones is achieved by using copper catalysts with 2,2'-bipyridine-based achiral ligands. Enantioenriched α-aminobenzylboron reactants bearing a hydrogen atom at the boron-bound stereogenic carbons undergo stereoinvertive coupling in the presence of a 6-phenyl-2,2'-bipyridine ligand with high enantiospecificity. α-Aminobenzylboronates bearing fully substituted boron-bound stereogenic centers also gave the 3,3-disubstituted isoindolinones with stereospecific stereochemical inversion in the presence of simple 2,2'-bipyridine as a ligand.