Innovative low-valent tetrylene photo- and cooperative catalysis via a rational design of ligands.

ended

Catalysis is a key technology in the European economy, industry and sustainable growth for a resilient future. However, many catalytic methods in use today are not outstanding in fundamental aspects such as activity, selectivity, substrate scope, toxicity or even cost efficiency. The rich structural diversity and associated reactivity provided by heavy elements from the Main Group offer unique opportunities for the prospective substitution of traditional catalysts based on precious metals by less expensive, more abundant, and potentially less toxic Main Group compounds. Sub-valent Ge(II) and Sn(II) derivatives are particularly appealing due to their reduced HOMO-LUMO gaps and thus increased reactivity. Nevertheless, bond activation processes lead to very stable and unreactive products in higher oxidation states (+IV). As such, catalytic turnover via reductive regeneration of the active species is highly challenging. To address this problem, an interdisciplinary approach will be used combining fundamental aspects stemming from a priori independent areas of Chemistry. Rationally designed ambiphilic and bifunctional derivatives will be used as ligands for low-valent tetrylenes to induce cooperativity between Main Group elements and Transition Metals and promote novel reactivity in small molecule activation and functionalization. Another objective is to demonstrate that selective irradiation of well-designed mononuclear tetrylene will allow photoactivation of chemical bonds that are thermally inert towards many of these divalent species. However, we envision that the main advantage of using light will be in facilitating reductive elimination processes in the cases where thermal catalytic turnover is hampered by this rate-limiting step. For this reason, these studies will also be extended to our hybrid systems, in what constitutes a completely innovative research area, and where the possible synergies and cooperative mechanisms will be analyzed.