cAAC-Light · New Strategies for Bond Activation and Catalysis with subvalent Main Group Complexes

This proposal aims to explore the feasibility and scope of thermal and light-driven bond activation and catalysis by sub-valent group 14 Main Group (MG) systems stabilized by highly σ-donating cAAC (cyclic (alkyl)amino carbene) ligands, exploiting their reduced HOMO-LUMO energy gaps, including MG-cAAC complexes, directly bonded MG/TM ( TM = transition metal) species and unprecedented hybrid MG/TM systems.We will initially target exotic cationic MG-cAAC complexes to investigate their capacity towards the activation of common E—H bonds (e.g. silanes, boranes or amines,including ammonia), including reversibility studies. This will be followed by exploring the activation of more challenging substrates, particularly the oxidative cleavage of C—H bonds. To enhance the capacity of activating less reactive bonds (e.g. intermolecular C—H, C—X…), as well as to enable more accessible reversibility routes (e.g. reversible H2 activation), we will target a variety of cooperative systems that will rely on the synergistic action of a MG element and a TM in close proximity. Investigating these synergistic effects will set the basis for designing more efficient systems in the search for innovative cooperative catalysis. In particular, this approach will permit the low-valent MG element to act as the activator, while the TM in close proximity may provide additional mechanistic routes for further functionalization. In the long term, we expect that our novel strategy will provide solid grounds for further developments in the vivid areas of low-valent MG chemistry and in particular in their use as catalysts for challenging transformations.