A variety of novel ligands have been generated by Vilsmeier formylation of
Hantzsch pyridines. These compounds which we call DOTTADs contain two aldeh
yde, imine or amine functions flanking a central pyridine nitrogen and can
be homochiral or crown derivatives. The synthesis and manipulation of these
systems is discussed. (C) 2000 Elsevier Science Ltd. Ail rights reserved.