Radical-Polar Crossover Enabled Triple Cleavage of CF<sub>2</sub>Br<sub>2</sub>: A Multicomponent Tandem Cyclization to 3-Fluoropyrazoles
Wanqing Zuo, Lingling Zuo, Xiao Geng, Zhifang Li, Lei Wang
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 CF 2 Br 2 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 CF 2 Br 2 and adds significant synthetic values to fluorine chemistry.
Topics & Concepts
SynthonChemistryTandemPolarReactivity (psychology)Cleavage (geology)Combinatorial chemistryCatalysisBond cleavageStereochemistryOrganic chemistryMedicineAstronomyFracture (geology)PhysicsGeotechnical engineeringEngineeringAlternative medicinePathologyMaterials scienceComposite materialFluorine in Organic ChemistryRadical Photochemical Reactions