ABSTRACT
Organic electrosynthesis is an emerging field that provides original selectivity while adding features of atom economy, sustainability, and selectivity. Electrosynthesis is often enhanced by redox mediators or electroauxiliaries. The mechanistic understanding of organic electrosynthesis is however often limited by the low lifetime of intermediates and its difficult detection. In this work, we report a computational analysis of the mechanism of an appealing reaction previously reported by Mei and co-workers which is catalyzed by copper and employs iodide as redox mediator. Our scheme combines DFT calculations with microkinetic modeling and covers both the reaction in solution and the electrodic steps. A detailed mechanistic scheme is obtained which reproduces well experimental data and opens perspectives for the general treatment of these processes.
ABSTRACT
The regioselective C-H activation of arenes remains one of the most promising techniques for accessing highly important functionalized motifs. Such functionalizations can generally be achieved through directed and non-directed processes. The directed approach requires a covalently attached directing group (DG) on the substrate to induce reactivity and selectivity and therefore intrinsically leaves a functional group at the point of attachment within the molecule, even after the tailored DG has been removed. Conversely, non-directed methods typically suffer from regioselectivity issues, especially for unbiased substrates. Herein, we report a unique approach that employs weak charge-charge and charge-dipole interactions to enable the meta-selective activation and olefination of arenes to address these challenges in Pd catalysis. The charged moiety can easily be converted to uncharged simple arenes by hydrogenation or cross-coupling. In-depth mechanistic studies prove that the charge is responsible for the observed selectivity. We expect our studies to be generalizable and thereby enable further regioselective transformations.
