Total Syntheses Supramolecular Style: Solid-State Construction of [2.2]Cyclophanes with Modular Control of Stereochemistry

Abstract

A series of templated solid-state reactions are used to construct the â&tild;bent' isomer of the [2.2]cyclophane family of molecules. Small-molecule hydrogen-bond-donor templates based on resorcinol complete the supramolecular construction of ortho-, meta-, and para-[2.2]cyclophanes in the solid state. The family of exo,exo-dicyclobutyl[2.2]cyclophanes forms regiospecifically in up to quantitative yields. The confines of the organic solid state and the modular nature of the template approach allow for the generation of a less stable exo,endo-[2.2]metacyclophane by simply changing the template to enforce a concomitant change in self-assembly. Our results demonstrate the first completed solid-state construction of each member of the family of [2.2]cyclophanes.