Rh(III)‐Catalysed Switchable and Chemoselective Synthesis of Difluorinated Pyrazolo[1,2‐<i>a</i>]indazolone and Indole Frameworks
Shuang Lin, Yi Wang, Zhi‐Huan Peng, Yuanyuan Li, Zhi Zhou, Hui Gao, Wei Yi
Abstract
Abstract Different from the classical defluorinated process for gem‐difluoromethylene alkynes, described herein is the chemodivergent synthesis of difluorinated pyrazolo[1,2‐a]indazolone and indole frameworks via Rh(III)‐catalysed regioselective C−H functionalization of phenidone with gem‐difluoromethylene alkynes in a switchable manner. The detailed reaction pathways and the origin of chemoselectivity were clarified through a combined experimental and computational mechanistic study, which involves different quench modes of C−Rh bond via protonolysis or C−N bond reductive elimination switched by the solvent
Topics & Concepts
ChemistryProtonolysisChemoselectivityRegioselectivityIndole testCombinatorial chemistrySurface modificationReductive eliminationCatalysisStereochemistryOrganic chemistryPhysical chemistryCatalytic C–H Functionalization MethodsCyclopropane Reaction MechanismsCatalytic Cross-Coupling Reactions