Asymmetric Syntheses of Protected Derivatives of Carnosadine and Its Stereoisomers as Conformationally Constrained Surrogates for Arginine

Template synthesis and physicochemical studies of 14-membered hexaazmacrocyclic complexes with Co(II), Ni(II), Cu(II) and Zn(II): a comparative spectroscopic approach on DNA binding with Cu(II) and Ni(II) complexes

“…A multiplet in the region 3.29-3.35 ppm may be assigned to the methylene protons (-N-CH 2 -N-, 8H) of the condensed aldehyde moiety. The aromatic ring protons show two sharp multiplets in the 7.49-7.92 ppm region, but no band could be identified for aldehydic protons, indicating that the proposed macrocyclic skeleton has been formed [28]. 13 C-NMR spectra of the zinc complexes show the expected number and positions of signals.…”

Synthesis and Characterization of 16, 17membered Tetra Aza Macrocyclic Complexes.

“…Another multiplet observed for all the complexes in the region 2.582.60 ppm may be assigned to the methylene proton between the nitrogen atoms (CH 2 N). The spectra of all the complexes showed multiplet in the region 6.216.40 ppm which corresponds (20) to the secondary amino protons (CNH). No compound exhibited signal corresponding to the carboxylic or secondary amino protons, which supports the proposed structure shown in Scheme 1.…”

Synthesis and characterization of N2S2-tin macrocyclic complexes of Co(II), Ni(II), Cu(II) and Zn(II)

“…The 1 H NMR spectra of Zn(II) dithiadiaza-tin macrocyclic complexes recorded in DMSO-d 6 show a multiplet in the 6.63-6.78 ppm region which can be assigned (Burgess et al, 1994) to the secondary amino protons of the o-bromoaniline indicating the replacement of primary amino proton by the diorganotin moiety. The 1 H-NMR spectra of the complexes do not show any signal corresponding to primary amino protons of the condensed o-bromoaniline moiety, suggesting that the proposed macrocyclic frameworks have been formed.…”