Synthesis of N-tetrasubstituted cyclam derivatives appended with sulfonyl or sulfinyl groups via aza-Michael addition

A novel tetrabranched neurotensin(8–13) cyclam derivative: Synthesis, 64Cu-labeling and biological evaluation

“…As summarized in Table 3, log D values (1-octanol/buffer system) showed that 64 Cu complexes of cyclam 1 and cyclamtetrapropionic acid 2 almost completely remain in the aqueous phase (N99.9%). The introduction of NT (8)(9)(10)(11)(12)(13) fragments into the ligand architecture leads to a slight increase of the lipophilicity, yielding distribution ratios for 64 Cu ⊂ 4, 64 Cu ⊂ 5 and 64 Cu ⊂ 7 in the same range as obtained for copper(II) complexes of bombesin conjugates with bispidine and TACN derivatives which showed rapid blood clearance and excretion via the renal pathway [66,67].…”

“…The dd bands of the copper(II) complexes with 4, 5 and 7 have the maximum at about 710 nm which is indicative for apical interactions of pendant arms of the copper(II)-N4 chromophore [64][65][66][67]. Molar absorptivity rises as the number of N-substituents is increased.…”

Functionalisation of Macroheterocycles with Preserving and Changing Their Sizes

“…Tetraphenylsulfonyl- (34) and optically pure tetraphenylsulfenyl-(35) substituted with cycles used for complexation with Cu 2+ and Eu 2+ ions are accordingly obtained by the interaction of unsubstituted cyclam (32) and a slight excess of phenyl vinyl sulfone (36) and (R)-р-tolyl vinyl sulfoxide (37) under aza-Michael reaction conditions (Scheme 8). [39] Tetra-N-substituted cyclen with carbamide side chains (38) are readily obtained by treatment with butyl isocyanate (4 equiv) of unsubstituted cyclen (31) (Scheme 9). [40] Aminocarboxylate derivatives turned out to be extremely valuable for obtaining highly stable chelates with lanthanoids.…”

C-Branched chiral (racemic) macrocyclic amino acids: structure of their Ni(ii), Zn(ii) and Cu(ii) complexes

“…1), generally carboxylic acids or their derivatives 3 (2)(3)(4), amines, 4 and more rarely phosphonic 5 and sulfonyl groups. 6 These structural modifications modulate the selectivity of a given chelating cavity from first-row transition divalent metal ions to the lanthanides. 7 The versatility of these structures as metal binding agents has been exploited in different fields ranging from antitumor agents, 8 biomedical applications (among others, contrast agents and shift reagents in magnetic resonance imaging (MRI) based techniques) 9 to luminescent sensors in optical methods.…”