Fig. 1: Indolizine.

a Pharmaceuticals derived from indolizine. b Traditional approaches for indolizine-carbaldehydes. c Our design: iminium ion/enamine tandem sequence strategy for trisubstituted indolizine-2-carbaldehydes. d This work: Unprecedented stereoauxiliary aminocatalysis with iminium ion/enamine strategy for the preparation of 1,2,3-trisubstituted indolizine-2-carbaldehydes via one-pot reaction.