Selective Synthesis of Hetero-Sequenced Aza-Cyclophanes

The selective synthesis of purely organic cages withhetero-sequenced functionalized cavities is demonstrated. Thestrategy to obtain these compounds is based on a stepwiseapproach using thermodynamically controlled imine condensa-tions. To accomplish this, the amine building blocks carry addi-tional azide groups, which act as masked amines and enablethe synthesis of the desired cavities. This approach offers a precise control of interior functionalization, the substitution pat-tern and the cage size, which is demonstrated by the selectivesynthesis of four cages. The largest described cage has beeninvestigated towards its ability for guest encapsulation and isable to selectively encapsulate functionalized arenes that offera matching substitution pattern.