SYNTHESIS OF UNSYMMETRICAL DINUCLEATING LIGANDS BEARING NITROGEN AND OXYGEN DONOR ATOMS

The synthesis of unsymmetrical dinucleating ligands bearing nitrogen a nd oxygen donor atoms is described. The Schiff-base condensation of fu nctionalised salicylaldehyde derivatives with primary amines gave rise to unsymmetrical unsaturated ligands, whereas condensation with secon dary amines followed by in situ reduction of the iminium species with sodium borohydride, led to the formation of unsymmetrical saturated li gands. The latter were also prepared by tandem Mannich reactions of 4- chlororesorcinol. Copyright (C) 1996 Elsevier Science Ltd