Asymmetric Michael addition of 1-acetylindolin-3-ones to β-nitrostyrenes catalyzed by bifunctional thioureas: a simple access to 2-functionalized indoles.

The first asymmetric Michael addition of 1-acetylindolin-3-ones to β-nitrostyrenes has been developed. 2-Substituted indolin-3-one derivatives were obtained with excellent yields (up to 99%) and good stereoselectivities (up to 28:1 dr and 92% ee), which could be transformed into 2-functionalized indoles easily without racemization. This achievement might further contribute to the chemistry and pharmacology of indole-related compounds.