Synthesis of complex fused polycyclic heterocycles utilizing IMDAF reactions of allylamino- or allyloxy-furyl(hetero)arenes
作者:Matthew L. Read、Andreas Krapp、Pedro O. Miranda、Lise-Lotte Gundersen
DOI:10.1016/j.tet.2011.12.079
日期:2012.2
carrying a halogen and an amino- or hydroxy group have been converted to allylamino- or allyloxy-furyl-(hetero)arenes. These compounds underwent IMDAF reactions to give complex fused polycyclic heterocycles. The reactivity of the substrates was highly dependent on the detailed substitution pattern, however cyclizations occurred with high stereoselectivity in most cases. Experimental findings regarding
The artificial nucleobases 6-(2′-thienyl)-purine (6TP) and 6-(2′-furyl)-purine (6FP) have been investigated in terms of their applicability in metal-mediated base pairs. In principle, these nucleobases should be capable of providing an S,N- and O,N-coordination environment, respectively. Two metal complexes have been synthesized and structurally characterized, using the N9-methylated derivatives of 6TP and 6FP as model nucleobases. The silver(I) complex [Ag(9-Me6TP)(CH3CN)(NO3)]n is of polymeric nature. The thienyl substituent is not involved in metal binding. In contrast, the dinuclear copper(II) complex [Cu(9-Me6FP)Cl2(OH2)]2 clearly shows that the furyl substituent can participate in the coordination of the metal ion. Oligonucleotide double helices comprising a 6TP:6TP or a 6FP:6FP mispair are slightly stabilized in the presence of silver(I). However, a distinction between the formation of a metal-mediated base pair and an unspecific binding event cannot be finally made. Based on these studies, it is proposed that the formation of Hoogsteen-type metal-mediated base pairs should be the more promising alternative compared with the originally anticipated Watson–Crick-type metal-mediated base pairs.
6-Arylpurines carrying a variety of substituents in the 9-position were prepared by Stille coupling between appropriately substituted 6-chloropurines and aryl(tributyl)tin, and the compounds were screened for antibacterial activity against Mycobacterium tuberculosis H-37-Rv. The lowest minimum inhibitory concentration value, 0.78 mug/mL, was found for 9-benzyl-2-chloro-6-(2-furyl)purine. This compound exhibited relatively low cytotoxicity, and it was active against several singly drug-resistant strains of M. tuberculosis.
7-Methyl-6-furylpurine forms dinuclear metal complexes with N3,N9 coordination
Abstract Two dinuclear metal complexes bearing the purinederivative 7-methyl-6-furylpurine (1b) as a ligand are reported. In [Ag2(1b)2(DMSO)2](ClO4)2·DMSO and [Cu2(1b)2(NO3)2], two bridging purinederivatives coordinate the two metal ions via their N3 and N9 positions. In the silver(I) complex, the coordination environment of each metal ion is completed by a DMSO ligand, whereas an additional nitrato