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Cucurbit[8]uril (CB[8]) is robust in encapsulating a stacking dimer of two identical or different aromatic units in water. In recent years, this ternary host–guest complexation motif has found wide applications in constructing supramolecular systems by noncovalently connecting molecular, supramolecular and polymeric precursors. This review summarises the important advance, in particular, in the generation of linear supramolecular polymers and extended supramolecular networks including periodic supramolecular organic frameworks.

The development of homogeneous, water-soluble periodic self-assembled structures comprise repeating units that produce porosity in two-dimensional (2D) or three-dimensional (3D) spaces has become a topic of growing interest in the field of supramolecular chemistry. Such novel self-assembled entities, known as supramolecular organic frameworks (SOFs), are the result of programmed host–guest interactions, which allows for the thermodynamically controlled generation of monolayer sheets or a diamondoid architecture with regular internal cavities or pores under mild conditions. This feature article aims at propagating the conceptually novel SOFs as a new entry into conventional supramolecular polymers. In the first section, we will describe the background of porous solid frameworks and supramolecular polymers. We then introduce the self-assembling behaviour of several multitopic flexible molecules, which is closely related to the design of periodic SOFs from rigid multitopic building blocks. This is followed by a brief discussion of cucurbit[8]uril (CB[8])-encapsulation-enhanced aromatic stacking in water. The three-component host–guest pattern based on this stacking motif has been utilized to drive the formation of most of the new SOFs. In the following two sections, we will highlight the main advances in the construction of 2D and 3D SOFs and the related functional aspects. Finally, we will offer our opinions on future directions for both structures and functions. We hope that this article will trigger the interest of researchers in the field of chemistry, physics, biology and materials science, which should help accelerate the applications of this new family of soft self-assembled organic frameworks.

This paper summarizes the recent advance in utilizing conjugated radical cation dimerization (CRCD) for constructing new unimolecular, such as foldamers, and supramolecular ordered structures, such as three-dimensional supramolecular polymers and two-dimensional supramolecular organic framework. Particularly, the stacking or dimerization of tetrathiafulvalene and 4,4′-dipyridium subunits has been highlighted, and the approaches for enhancing the stability of their radical cation dimers have been discussed.

ConspectusIn host–guest chemistry, a larger host molecule selectively and noncovalently binds to a smaller guest molecule or ion. Early studies of host–guest chemistry focused on the recognition of spherical metal or ammonium ions by macrocyclic hosts, such as cyclic crown ethers. In these systems, preorganization enables their binding sites to cooperatively contact and attract a guest. Although some open-chain crown ether analogues possess similar, but generally lower, binding affinities, the design of acyclic molecular recognition hosts has remained challenging. One of the most successful examples was rigid molecular tweezers, acyclic covalently bonded preorganized host molecules with open cavities that bind tightly as they stiffen.Depending on the length of the atomic backbones, hydrogen bonding-driven aromatic amide foldamers can form open or closed cavities. Through rational design of the backbones and the introduction of added functional groups, researchers can regulate the shape and size of the cav...

An efficient method for the preparation of unsymmetrical ethers from alcohols catalyzed by sodium bisulfite is reported. The procedure enables the direct dehydration of primary, secondary, and tertiary benzylic alcohols with aliphatic alcohols in the absence of solvent to selectively produce unsymmetrical ethers in high yields with low catalyst loading. No symmetrical ethers are generated in the reactions. The etherification of a chiral secondary benzyl alcohol with butanol exclusively yields racemic ethers, suggesting that the reaction involves a carbocation intermediate mechanism.

An α-aminooxy monomer with polar hydroxymethyl side chain (X) is synthesized from L-serine in 15% overall yield.

Irradiation of amido selenides in the presence of Yb(O-Tf)3 allows an efficient, regiospecific, and stereoselective access to γ- and δ-lactams.

Unusual products were isolated from reactions of [60]fullerene with cyclopentenyl or cyclohexenyl pyrrolidine and piperidine. The structures of products were characterized by spectroscopic means. A possible thermoinduced electron-transfer mechanism for the new reaction was proposed.

A novel and convenient one-pot synthesis of trimethyl 3,5,5-piperidonetricarboxylate was reported. Cocatalyzed by Yb(OTf)3 and AgOTf under mild conditions, a piperidone containing a β-amino acid template was synthesized from dimethyl malonate and formaldehyde O-benzyl oxime in high yield. It could be a useful building block for the synthesis of multisubstituted piperidine derivatives.