Pseudo-halogen behavior of thiophosphoryl azides as a tool for the functionalization of phosphorus macrocycles

Phosphoryl azides are known as azide-transfer agents in organic chemistry; such behavior denotes the pseudo-halogen character of the azide group when linked to a tetracoordinated phosphorus atom, but it was considered up to now only for the functionalization of organic substrates by N3. We show in this paper that the azide can also be considered as a good leaving group, which facilitates the functionalization of the phosphorus atom which bore it. This reaction is first demonstrated on a small thiophosphoryl azide, then applied to the functionalization of more complex macromolecules, i.e. macrocycles incorporating in their structure thiophosphoryl azido groups.