Synthesis of 5‐Trifluoromethyl‐1,2,4‐Triazoles via Metal‐Free Annulation of Trifluoroacetimidohydrazides and Methyl Ketones
Jiajun Zhang, Jianhua Tang, Zhengkai Chen, Xiao‐Feng Wu
Abstract
Abstract A metal‐free approach for the synthesis of 5‐trifluoromethyl‐1,2,4‐triazoles via I 2 ‐mediated [4+1] annulation of readily available trifluoroacetimidohydrazides and methyl ketones has been achieved. The transformation involves iodination/Kornblum oxidation, intermolecular dehydration condensation and an iodine‐mediated intramolecular cyclization/aromatization sequence. The developed protocol can be easily scaled up to 3 mmol scale without obvious efficiency decrease and be implemented by a consecutive one‐pot manner. magnified image
Topics & Concepts
AnnulationChemistryTrifluoromethylAromatizationIntramolecular forceCondensationIntermolecular forceCombinatorial chemistryHalogenationStereochemistryMedicinal chemistryOrganic chemistryMoleculeCatalysisThermodynamicsAlkylPhysicsFluorine in Organic ChemistryCatalytic C–H Functionalization MethodsSynthesis and Biological Evaluation