N -Phosphorylation of daunorubicin—synthetic approaches and antiproliferative properties of the products

Synthetic approaches to daunorubicin derivatives containing azide and propargyl fragments were developed. A series of phosphonate and bisphosphonate derivatives (including those containing P–C–P fragments) were obtained by the methods of click chemistry and by direct amidation. The obtained compounds show small cytotoxicity not higher than that of parent daunorubicin. Graphical abstract