Borane-catalysed C2-selective indole reductive functionalisation

Abstract

Indolines are common motifs within pharamceuticals and natural products. Boron catalysis enables the chemoselective allylation of indoles to give allylic indolines in excellent diastereoselectivity. Mechanistic studies revealed in situ formation of the allylic borane, allylation of the imine tautomer of the indole and B–N/B–H transborylation for catalytic turnover.