Intramolecular Anodic Olefin Coupling Reactions: Using Competition Studies to Probe the Mechanism of Oxidative Cyclization Reactions
A competition experiment was designed so that the relative rates of anodic cyclization reactions under various electrolysis conditions can be determined. Reactions with ketene dithioacetal and enol ether-based substrates that use lithium methoxide as a base were shown to proceed through radical cation intermediates that were trapped by a sulfonamide anion. Results for the oxidative coupling of a vinyl sulfide with a sulfonamide anion using the same conditions were consistent with the reaction proceeding through a nitrogen-radical.
Hai-Chao Xu and Kevin D. Moeller
Org. Lett., 2010, 12 (8), 1720–1723