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Updated: Sep 23, 2025

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
Published on: June 10, 2021
A strained alkyne-containing bipyridine reagent; synthesis, reactivity and fluorescence properties
Sam Forshaw1, Richard C Knighton1, Jami Reber1
1Department of Chemistry, The University of Warwick Coventry CV4 7AL UK m.wills@warwick.ac.uk.
Abstract:
We report the synthesis of a bipyridyl reagent containing a strained alkyne, which significantly restricts its flexibility. Upon strain-promoted alkyne-azide cycloaddition (SPAAC) with an azide, which does not require a Cu catalyst, the structure becomes significantly more flexible and an increase in fluorescence is observed. Upon addition of Zn(ii), the fluorescence is enhanced further. The reagent has the potential to act as a fluorescent labelling agent with azide-containing substrates, including biological molecules.
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