Pd-catalyzed dearomative arylborylation of indoles

A palladium-catalyzed dearomative arylborylation of indoles is reported, which provides straightforward access to structurally diverse indolines bearing vicinal tetrasubstituted and borylated trisubstituted stereocenters in moderate to good yields with excellent diastereoselectivities. By using a BINOL-based chiral phosphoramidite ligand and an sp(2)-sp(3) mixed-boron reagent, an enantioselective dearomative arylborylation was achieved and chiral boron-containing products were accessed in up to 94% ee. Synthetic tranformations of the resulting organoborons were conducted to afford a number of unique indoline derivatives.