C ₂ ‐Symmetric Chiral Amine Catalysts With N,N'‐Axially Chiral Bipyrrole Framework: Design, Synthesis, and Asymmetric Catalytic Applications

A concise and stereoselective synthesis of novel C 2 ‐symmetric N,N′‐axially chiral secondary amine catalysts is presented. Direct chromatographic separation of diastereomeric intermediates on silica gel provided facile access to both atropisomeric forms, enabling subsequent structural and electronic modifications. The utility of these secondary amine catalysts was demonstrated in asymmetric Michael reactions, affording the products in good yields with good to excellent enantioselectivities.