Affiliation:
1. Polymer Chemistry and Catalysis Leibniz-Institute for Catalysis Albert-Einstein-Str. 29a 18059 Rostock Germany
2. Department of Biotechnology and Enzyme Catalysis Institute of Biochemistry University of Greifswald Felix Hausdorff-Str. 4 17487 Greifswald Germany
3. Institute of Chemistry Technical University of Berlin Straße des 17. Juni 115 10623 Berlin Germany
Abstract
AbstractAllylic functionalization reactions are an important tool for constructing many organic compounds, as they allow for the insertion of the versatile allyl group. Numerous catalytic processes have been developed, primarily utilizing noble metals such as palladium and pre‐functionalized substrates. Conversely, the copper‐catalyzed oxidative C−H derivatization route, whether thermal or photocatalyzed, remains relatively underdeveloped. This is mostly due to the lack of a general concept and corresponding mechanistic understanding. Here we present a comprehensive analysis of the mechanism of this transformation. We utilized a range of spectroscopic techniques, including UV‐Vis, NMR, and EPR, single crystal x‐ray diffraction, as well as cyclovoltammetry, and DFT calculations. We propose that there are no free organic radicals involved in this cross‐dehydrogenative coupling, and that the reaction pathway is analogous to the well‐known Karash‐Sosnovsky reaction.