Dual catalysis for the redox annulation of nitroalkynes with indoles: enantioselective construction of indolin-3-ones bearing quaternary stereocenters

Abstract

The enantioselective redox annulation of nitroalkynes with indoles is enabled by gold/chiral phosphoric acid dual catalysis. A range of indolin-3-one derivatives bearing quaternary stereocenters at the C2 position were afforded in good yields and excellent enantioselectivities (up to 96 % ee) from readily available starting materials.

Keywords: asymmetric catalysis; carbenoids; chiral phosphoric acids; gold; indolinones.