Nature Communications, Published online: 20 June 2026; doi:10.1038/s41467-026-74668-8 Acyclic Schiff base atropisomers have remained inaccessible because of longstanding synthetic and stereocontrol challenges. Here, the authors report a palladium-catalysed asymmetric N-allylation enabled by substrate guided catalyst evolution, delivering Z selective atropisomeric Schiff bases with high yields and enantioselectivities.