Recyclable copper catalyst on chitosan for facile preparation of alkyl/aryl mixed phosphates via deaminated esterification between diphenylphosphoryl azides and aliphatic alcohols

An efficient methodology was established for the preparation of alkyl/aryl mixed phosphates under aerobic conditions promoted by a easily recoverable heterogeneous catalyst. This highly active copper catalyst was obtained by directly mixing of copper precursor with chitosan solution, followed by a simple work-up process. In this catalytic system, different phosphoryl azides and aliphatic alcohols were employed to generate desired products in moderate to excellent yields with good functional group tolerance. This protocol provided a practical application of the chitosan supported heterogeneous copper catalyst towards a novel P-O bond formation.