cis-diprotected cyclams and cyclens: A new route to symmetrically or asymmetrically 1,4-disubstituted tetraazamacrocycles and to asymmetrically tetrasubstituted derivatives

Abstract : The use of cyclam and cyclen oxamides as intermediates for the synthesis of N1,N4-disubstituted tetraazamacrocycles is reported. This pathway affords a general strategy for the preparation of symmetrically or asymmetrically disubstituted derivatives in good yields. Also these intermediates proved convenient synthons for the preparation of asymmetrically tetrasubstituted macrocycles, leading to a new class of potentially dinucleating ligands. © The Royal Society of Chemistry 1999.