Supramolecularly regulated copper-bisoxazoline catalysts for the efficient insertion of carbenoid species into hydroxyl bonds†
The catalytic insertion of copper carbenoids into O–H bonds affords synthetically useful α-alkyl/aryl-α-alkoxy/aryloxy derivatives. Herein, the design, preparation and application of supramolecularly regulated copper(I) complexes of bisoxazoline ligands is reported. We have demonstrated that the catalytic performance of these systems can be modulated by the use of an external molecule (i.e. the regulation agent), which interacts with a polyethyleneoxy chain on the ligand (i.e. the regulation site) via supramolecular interactions. This approach has been applied to an array of structurally diverse alcohols (cycloalkyl, alkyl and aryl derivatives). Moreover, we have used this methodology to synthesise advanced synthetic intermediates of biologically relevant compounds.