Transition Metal‐Chelating Phase Transfer Agents from 3,4‐Disubstituted Benzylhalides

A unified approach to the synthesis of chelating phase transfer agents which uses attachment of various side-chains to a single chelating molecular precursor (such as 2-acetyl-4-chloromethyl phenol, 4-chloromethyl salicylaldehyde, 5-chloromethyl-8-hydroxyquinoline), by alkylation at carbon (on aromatic substrates), at oxygen (on alkanols, oligoethylene glycols) or at nitrogen (dialkylamines), is presented. The reaction of a model precursor, 2-acetyl-4-chloromethyl phenol, is studied in detail. The proton–ligand and proton–metal stability constants and Cu(II) phase transfer properties is determined.