Angewandte Chemie International Edition · 2020 · 203 citations · 37 references
Natural SciencesChemical EngineeringChemistryCatalysisElectrochemical EngineeringOrganic ChemistryCatalytic MechanismsCross-coupling ReactionsElectrochemical SynthesisOrganic SynthesisAmine FunctionalizationAnodic SynthesisCarbocation IntermediatesElectrochemical AminationElectrochemical C - N Bond FormationMetal CatalystsNucleophile ReactivityOxidation
Abstract C−H/N‐H cross‐coupling is an ideal strategy to synthesize various amines but remains challenging owing to the requirement for sacrificial chemical oxidants and the difficulty in controlling the regio‐ and chemo‐selectivity. Herein we report a site‐selective electrochemical amination reaction that can convert benzylic C−H bonds into C‐N linkages via H 2 evolution without need for external oxidants or metal catalysts. The synthetic strategy involves anodic cleavage of benzylic C−H to form a carbocation intermediate, which is then trapped with an amine nucleophile leading to C−N bond formation. Key to the success is to include HFIP as a co‐solvent to modulate the oxidation potentials of the alkylbenzene substrate and the aminated product to avoid overoxidation of the latter.
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Powering the Future: How Can Electrochemistry Make a Difference in Organic Synthesis?
Tjark H. Meyer, Isaac Choi, Cong Tian et al. · Chem · 2020 · 513 citations · Full text