Fig. 4: Catalystic properties.

a Optimization of solvent conditions for three-component aza-Darzens reaction in the presence of 0.2 mol% Zn₂Er₈L³₈. b The yield change of product 4a catalyzed by various cages over time. Reaction conditions: 0.5 mmol aniline, 0.6 mmol formaldehyde, 0.7 mmol α-diazo ester, 0.4 mol% catalyst. c ¹H NMR monitor for the formation of the disubstituted N-aryl aziridine product 5a catalyzed by 0.2 mol% Zn₂Er₈L³₈. Reaction conditions: 0.5 mmol aniline, 1.0 mmol benzaldehyde, 0.7 mmol α-diazo ester. The changes of ¹H NMR signals are showed in color regions (400 MHz, 298 K, CDCl₃).