Atroposelective synthesis of axially chiral indolizinylpyrroles by catalytic asymmetric Paal–Knorr reaction

We present herein a highly efficient atroposelective synthesis of five/five-membered N-indolizinylpyrrole through the chiral phosphoric acid (CPA) catalyzed Paal-Knorr reaction of 3-aminoindolizines and 1,4-diketones. The reaction features mild reaction conditions, broad substrate scope and excellent enantioselectivity. Moreover, this method provides a facile approach to a novel axially chiral indolizine-pyrrole framework.