A Convenient Synthetic Route to Polyether‐Tagged Cyclam Ligands andTheir Nickel Derivatives
A specific strategy is described for the synthesis of stable polyethylene oxide tagged tetraazamacrocycles (PEO-cyclam) in five steps (overall yields for 12 and 13 48% and 22%, respectively). Various attempts via classical pathways demonstrated: (i) the low reactivity of PEO derivatives, and (ii) the necessity of a stabiliser arm between the cyclam and the PEO chain. Nickel complexes have been prepared and characterised by electrochemistry.