A Strategy for the Synthesis of Phosphorus‐Containing Macrocycles—Ligands for Exceptional Coordination Geometries

The shape of rings to come! The novel synthetic strategy for macrocycles containing differently functionalized ligands is based on a coupling reaction between two alkali‐metal‐fixed carbanionic centers I and two specifically connected, electrophilic phosphorus centers II (see scheme, Do=donor atom). Twofold PC‐bond formation first results in a metallamacrocycle III , which is subsequently converted by protonation into the neutral ring system IV . The formation of unprecedented coordination geometries of Cu I and Ni 0 centers is shown by the X‐ray crystal structures of the complexes V .