Atroposelective Synthesis of 1,1′-Bipyrroles Bearing a Chiral N-N Axis: Chiral Phosphoric Acid Catalysis with Lewis Acid Induced Enantiodivergence

We present herein a highly efficient atroposelective synthesis of axially chiral 1,1'-bipyrroles bearing an N-N linkage from simple hydrazine and 1,4-diones. Further product derivatizations led to axially chiral bifunctional compounds with high potential in asymmetric catalysis. For this chrial phosphoric acid (CPA)-catalyzed double Paal-Knorr reaction, an intriguing Fe(OTf)(3)-induced enantiodivergence was also observed.

Automated summary

We present a highly efficient method for the synthesis of axially chiral 1,1'-bipyrroles. The method involves the use of simple hydrazine and 1,4-diones as starting materials and further derivatization to obtain axially chiral bifunctional compounds with high potential in asymmetric catalysis.