Cu12-Methylsilsesquioxane Cage Decorated with Cu(dppe)2 Moieties for Mild Oxidative Functionalization of Alkanes.

We report a high nuclear (Cu14) complex synthesized via the self-assembly of copper-methylsilsesquioxane induced by the complexation with 1,2-bis(diphenylphosphino)ethane (dppe). The structure includes two cationic CuI(dppe)2 moieties and an anionic silsesquioxane cage of an unprecedented CuII12 structural type. The Cu12 cage fragment exhibits a unique (i) combination of Si4-cyclic/Si2-acyclic silsesquioxane ligands and (ii) encapsulation of two different chloride and carbonate species. This complex acts as a promising precatalyst in the mild oxidation and carboxylation of light alkanes to produce alkyl hydroperoxides, alcohols, ketones, or carboxylic acids. The present study widens the family of copper-methylsilsesquioxane clusters with prospective use in oxidation catalysis.