Amazing stuff! Headline of the day! Let it click! Or let it whip like the Dazz Band!
"Click reactions—the subject of the 2022 Nobel Prize in Chemistry—come in many forms, but they all share a few key features. Namely, click chemistry forges new chemical bonds quickly, selectively, and irreversibly.
That last feature has now become a bit more optional.
A team ... have published a paper detailing their radical new approach to click chemistry: a bond formation between phenothiazine dyes and amines that can be undone using ultraviolet light ..."
From the editor's summary and the abstract:
"Editor’s summary
Click chemistry refers to a growing class of coupling reactions that proceed rapidly to high conversion under mild conditions while avoiding competing pathways and generating relatively little waste. The main drawback to this technique is that the strong driving force underlying these favorable properties tends to prevent reversibility. Zhao et al. report an oxidative coupling between amines and phenothiazines that manifests click-like efficiency at room temperature. However, the resulting sulfur-nitrogen bond can be reductively cleaved with similar efficiency by irradiation in the near-ultraviolet range. ...
Abstract
Click reactions, which are characterized by rapid, high-yielding, and highly selective coupling of two reaction partners, are powerful tools in synthesis but are rarely reversible. Innovative strategies that reverse such couplings in a precise and on-demand manner, enabling a click-clip sequence, would greatly expand the technique’s versatility. Herein, a click and clip reaction pair is demonstrated by manipulation of a sulfilimine linkage. Phenothiazines and amines are rapidly and quantitatively coupled through oxidative sulfilimine bond formation with N-bromosuccinimide, and the resulting sulfilimine bromides then undergo quantitative reversion to the phenothiazines and amines through photoreduction at 380 nanometers. This protocol enables fabrication of depolymerizable macromolecules and reversible modification of aminosaccharides, demonstrating high selectivity and efficiency for manipulating sulfilimine linkages in complex systems."
Radical-mediated click-clip reactions (no public access)
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