Diversity-Oriented Construction and Interconversion of Multicavity Supermacrocycles for Cooperative Anion-π Binding.

A one-pot strategy for the diverse construction of a series of supermacrocycles was realized using rationally designed macrocyclic precursors. The base was found to have a significant effect not only on the size distribution but also on the structure of the supermacrocycles formed. While the use of less CsF (<4.0 equiv) afforded regular supermacrocycles containing up to four macrocyclic precursor subunits, the use of more CsF (>8.0 equiv) resulted in structurally reorganized supermacrocyles featuring oxacalix[2]arene[2]triazine motifs. Base-mediated supermacrocycle-to-supermacrocycle transformations were also revealed. With large cavities and many electron-deficient triazine moieties, the supermacrocyles can accommodate large organic anions via multiple anion-π interactions as demonstrated for two supermacrocycles, which can host 2-carboxyacetate and represent the first crystallographic examples of sandwich-like structures with anion-π interactions.