Anion-pi Confined Catalysis – APICOCAT

Anion-pi interactions are non-covalent interactions between an electron deficient aromatic surface with a positive quadrupolar moment and an anion. They are largely underexplored, particularly in the field of catalysis because of their recent discovery. They are often described as the counterpart of cation-pi interactions, which are well known to participate in transition state stabilization in enzymes, and as such promise to access exceptional activities and selectivities. Enzymes are known to transform substrates with high specificity and delivering product with high chemo and stereo selectivity. These characteristics are made possible by burying the active site into a well-defined pocket surrounded by amino acid side chains, allowing transition state stabilization by multiple non-covalent interactions. To mimic enzymes, covalent molecular cages are of interest because they could reproduce the defined microenvironment found in Nature’s catalysts. Anion-pi interactions are new to Nature interactions, and we propose to incorporate these interactions into molecular cages to develop new reactivity. This proposal will aim at synthesizing electron deficient molecular cages based on a preorganized unit having a C3 symmetry axis, functionalized by three electron deficient aromatic surfaces having a large positive quadrupolar moment and capped with an additional endohedral catalytic or recognition unit. Once obtained, the molecular cages will be characterized by different spectroscopic methods to grasp the effect of confinement on the electronic and physicochemical properties of the functional units. These objects will then be used for the selective recognition of environmental and biological relevant anions such as nitrates, carbonates or phosphates. Finally, stereoselective reactions will be investigated by the anion-pi confined catalysts with the aim to deliver unprecedented activity and stereoselectivity and to develop new catalytic reactions.