Amplification sensing manipulated by a sumanene-based supramolecular polymer as a dynamic allosteric effector.

The synthesis of signal-amplifying chemosensors induced by various triggers is a major challenge for multidisciplinary sciences. In this study, a signal-amplification system that was flexibly manipulated by a dynamic allosteric effector (trigger) was developed. Herein, the focus was on using the behavior of supramolecular polymerization to control the degree of polymerization by changing the concentration of a functional monomer. It was assumed that this control was facilitated by a gradually changing/dynamic allosteric effector. A curved-π buckybowl sumanene and a sumanene-based chemosensor (SC) were employed as the allosteric effector and the molecular binder, respectively. The hetero-supramolecular polymer, (SC·(sumanene)n), facilitated the manipulation of the degree of signal-amplification; this was accomplished by changing the sumanene monomer concentration, which resulted in up to a 62.5-fold amplification of a steroid. The current results and the concept proposed herein provide an alternate method to conventional chemosensors and signal-amplification systems.

Sumanene-stacked supramolecular polymers. Dynamic, solvation-directed control.

In this study, we found that a pristine buckybowl, sumanene, can form solution-state supramolecular polymers. We also demonstrated that sumanene supramolecular polymers can be dynamically controlled by external stimuli, in which solvation plays a significant role. This study not only provides new guidelines for the rational design of supramolecular polymers, particularly for the use of buckybowls, but also presents interesting dynamic behaviors of supramolecular polymerization.

C-H Triflation of BINOL Derivatives Using DIH and TfOH.

C-H trifluoromethanesulfonyloxylation (triflation) of 1,1'-bi-2-naphthol (BINOL) derivatives has been established under mild conditions using 1,3-diiodo-5,5-dimethylhydantoin (DIH) and trifluoromethanesulfonic acid (TfOH). Up to eight TfO groups can be introduced in a single operation. The resulting highly oxidized BINOL derivatives can be successfully converted to 8,8'-dihydroxy BINOL and bisnaphthoquinone compounds. Mechanistic studies suggested that C-H triflation occurs in the form of an aromatic substitution reaction via the in situ formation of a radical cation.