One‐Pot and Shape‐Controlled Synthesis of Organic Cages

Abstract

Organic cages are fascinating because of their well‐defined 3D cavities, excellent stability, and accessible post‐modification. However, the synthesis is normally realized by fragment coupling approach in low yields. Herein, we report one‐pot, gram‐scale and shape‐controlled synthesis of two covalent organic cages (box‐shaped [4]cage and triangular prism‐shaped [2]cage) in yields of 46 % and 52 %, involving direct condensation of triangular 1,3,5‐tris(2,4‐dimethoxyphenyl)benzene monomer with paraformaldehyde and isobutyraldehyde, respectively. The cages can convert into high‐yielding per‐hydroxylated analogues. The [2]cage can be utilized as gas chromatographic stationary phase for high‐resolution separation of benzene/cyclohexane and toluene/methylcyclohexane. By changing the central moiety of the triangular monomer and/or aldehyde, this synthetic method would have the potential to be a general strategy to access diverse cages with tunable shape, size, and electronic properties.

Symmetrically Tetra‐functionalized Pillar[6]arenes Prepared by Fragment Coupling

“…Although one‐pot synthesis of macrocycles [24–29] is quite fascinating, two‐step fragment coupling has also attracted much attention, as this approach could incorporate different repeating units onto the macrocycles in the first place [30–46] . It occurred to us that this strategy could be feasible for synthesizing symmetrically tetra‐functionalized pillar[6]arenes.…”

Modular Introduction of endo‐Binding Sites in a Macrocyclic Cavity towards Selective Recognition of Neutral Azacycles

“…In 2015, we brought a new family of macrocycles, biphen[n]arenes, [13,14] into supramolecular chemistry, and have constructed a series of functionalized biphen-[n]arenes [15] and triphen[n]cages [16] with various skeletons and cavity sizes during the past seven years. However, all these macrocycles and cages do not have endo-binding sites, and only exhibit general binding capacities.…”