Zinc-Enabled Annulation of Trifluorodiazoethane with 2<i>H</i>-Azirines to Construct Trifluoromethyl Pyrazolines, Pyrazoles, and Pyridazines
Yue-Ji Chen, Fa‐Guang Zhang, Jun‐An Ma
Abstract
A diethylzinc-promoted unconventional annulation reaction of 2,2,2-trifluorodiazoethane with 2H-azirines is described. This transformation involves two [3 + 2] cycloaddition steps and one dinitrogen extrusion process in one pot, thus giving a broad array of 3-trifluoromethyl pyrazolines in good yields with excellent diastereoselectivities. Further transformations provide facile access to 3-trifluoromethyl pyrazoles and 3,5-ditrifluoromethyl pyridazines with good efficiency.
Topics & Concepts
AnnulationTrifluoromethylChemistryDiethylzincCycloadditionCombinatorial chemistryExtrusionMedicinal chemistryOrganic chemistryCatalysisEnantioselective synthesisMaterials scienceMetallurgyAlkylFluorine in Organic ChemistryCyclopropane Reaction MechanismsSynthesis and Catalytic Reactions