Jessica Bieniek: Electrochemical Synthesis of N,N’-Disubstituted Indazolin-3-ones
- Date: May 25, 2022
- Speaker: Jessica Bieniek
The first broadly applicable and sustainable electrochemical synthesis of N,N’ disubstituted indazolin-3-ones by direct intramolecular anodic dehydrogenative N-N coupling reaction is presented. This method features mild reaction conditions, an easy experimental setup, sustainable and inexpensive electrode materials and a low supporting electrolyte concentration, providing access to various indazolin-3-one derivatives in good yields up to 78%. The reaction conditions were optimized applying the statistics-based method Design of Experiments (DoE) and the excellent scalability of the reaction was demonstrated. Additionally, cyclic voltammetry experiments were conducted to get insights into the reaction mechanism. Indazolin-3-ones represent an important class of N-heterocycles due to their broad range of biological activity, such as anti-inflammatory, anticancer and antichagasic properties. However, conventional indazolin-3-one syntheses often involve harsh reaction conditions, the use of toxic reagents in stoichiometric amounts or transition metal catalysts, leading to large amounts of reagent waste, high costs and safety hazards. In contrast, electro-organic chemistry has proven to provide a sustainable and broadly applicable synthetic tool for the synthesis of various N-heterocycles. By applying current as a traceless oxidant, reagent waste can be diminished, work safety increased and costs lowered.