Copper-Catalyzed Diastereo- and Enantioselective Borylative Cyclization: Synthesis of Enantioenriched 2,3-Disubstituted Indolines.

The development of an efficient, straightforward approach for access to a wide range of enantioenriched boron-containing 2,3-disubstituted indolines via highly chemo-, diastereo-, and enantioselective copper-catalyzed intramolecular boraylative cyclization of readily available 2-styrylimines is reported. This reaction proceeds under very mild conditions and displays a high degree of functional group compatibility. The practicability of this approach is demonstrated by a gram-scale reaction and further transformations of the chiral borylated indolines.