Electrosynthesis of 1,2,3-Benzotriazines through an Iodide-Catalyzed Skeletal Editing of 3-Aminoindazoles.

This report describes an environmentally benign synthesis of 1,2,3-benzotriazines through an iodide-catalyzed electro-oxidative N-centered [1,2]-rearrangement of 3-aminoindazoles. The developed method demonstrates the activation of heteroatoms via electrochemically generated reactive iodide species without using any metal catalysts and peroxides. The protocol features practical and mild reaction conditions and displays a wide substrate scope.

Metal-Free Electrocatalytic Synthesis of Fused Azabicycles from -Allyl Enamine Carboxylates.

An electrocatalytic approach to access structurally significant azabicyclic scaffolds from -allyl enamine carboxylates is illustrated. This metal-free method functions exclusively with a catalytic amount of iodide, strategically employed to electrochemically generate a reactive hypervalent iodine species, which facilitates the cascade bicyclization processes with enhanced precision and efficiency. Excellent functional group compatibility was observed, enabling the synthesis of a series of azabicycle derivatives.

Synthesis of Quinoxalines through Cu-electrocatalytic Azidation/Annulation Cascade at Low Catalyst Loading.

A Cu-electrocatalytic azidation of -aryl enamines and subsequent denitrogenative annulation for the construction of quinoxaline frameworks is reported. Only 0.5 mol % of copper(II) chloride was employed for this cascade transformation displaying excellent functional-group compatibility even with complex bioactive scaffolds.

Electrochemical Organoselenium Catalysis for the Selective Activation of Alkynes: Easy Access to Carbonyl-pyrroles/oxazoles from -Propargyl Enamines/Amides.

Intramolecular electro-oxidative addition of enamines or amides to nonactivated alkynes was attained to access carbonyl-pyrroles or -oxazoles from -propargyl derivatives. Organoselenium was employed as the electrocatalyst, which played a crucial role as a π-Lewis acid and selectively activated the alkyne for the successful nucleophilic addition. The synthetic strategy permits a wide range of substrate scope up to 93% yield.

Regioselective Synthesis of -Aryl 1,2,3-Triazoles via Electro-oxidative Coupling of Enamines and Aryldiazonium Salts.

An efficient synthetic route for the construction of -aryl 1,2,3-triazoles is reported via sequential C-N bond formation and electro-oxidative N-N coupling under metal-free conditions. Readily accessible 2-aminoacrylates and aryldiazonium salts were used as starting materials, and the developed protocol displays excellent functional group tolerance, allowing an extensive range of substrate scope up to 91% isolated yield. Various mechanistic studies, along with the isolation of an intermediate adduct, refer to successive ionic and radical reaction sequences.

Trifluoroethanol as a Unique Additive for the Chemoselective Electrooxidation of Enamines to Access Unsymmetrically Substituted NH-Pyrroles.

An electrochemical method for the synthesis of unsymmetrically substituted NH-pyrroles is described. The synthetic strategy comprises a challenging heterocoupling between two structurally diverse enamines via sequential chemoselective oxidation, addition, and cyclization processes. A series of aryl- and alkyl-substituted enamines were effectively cross-coupled from an equimolar mixture to synthesize various unsymmetrical pyrrole derivatives up to 84 % yield.