Application of 3‑Methyl-2-vinylindoles in Catalytic Asymmetric Povarov Reaction: Diastereo- and Enantioselective Synthesis of Indole-Derived Tetrahydroquinolines

The first application of 3-methyl-2-vinylindoles
in catalytic asymmetric
Povarov reactions has been established via the three-component reactions
of 3-methyl-2-vinylindoles, aldehydes, and anilines in the presence
of chiral phosphoric acid, providing easy access to chiral indole-derived
tetrahydroquinolines with three contiguous stereogenic centers at
high yields (up to 99%) and with excellent diastereo- and enantioselectivities
(all >95:5 dr, up to 96% ee). This mode of catalytic asymmetric
three-component
reaction offers a step-economic and atom-economic strategy for accessing
enantioenriched indole-derived tetrahydroquinolines with structural
diversity and complexity.