NHC-Copper-Catalyzed Asymmetric Dearomative Silylation of Indoles

We report an asymmetric dearomative
silylation reaction of 3-acylindoles
using a chiral NHC-copper­(I) complex as catalyst to afford a range
of cyclic α-aminosilanes with high regio- and enantioselectivity.
Initial mechanistic studies revealed that the observed high diastereoselectivity
was attributed to the facile epimerization of the 3-acyl group. We
also demonstrated that the product could be used as a versatile precursor
for the synthesis of functionalized indolines in high enantiomeric
purity.