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Updated: Jul 19, 2025

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
Published on: June 10, 2021
Radical-Polar Crossover Enabled Triple Cleavage of CF2Br2: A Multicomponent Tandem Cyclization to 3-Fluoropyrazoles
Wanqing Zuo1,2, Lingling Zuo1, Xiao Geng1
1Advanced Research Institute and School of Pharmaceutical Sciences, Taizhou University, Jiaojiang 318000, Zhejiang. P. R. China.
Abstract:
The elaboration of step-economy and catalytic approaches for accessing diverse fluorinated heterocyclics is highly desirable. Described herein is a radical-polar crossover enabled three-component cyclization to polysubstituted fluoropyrazoles by using CF2Br2 as a novel C1F1 synthon. Mechanistic experiments revealed that the in situ generation of the reactive intermediate gem-difluorovinylimine ion is the key to this transformation. This protocol unlocks the novel reactivity of CF2Br2 and adds significant synthetic values to fluorine chemistry.
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