title: Synthesis of mono- and di-[12]aneN3 ligands and study on the catalytic cleavage of RNA model 2-hydroxypropyl-p-nitrophenyl phosphate with their metal complexes.
abstract: A series of mono- and di-[12]aneN(3) ligands 1-6, which contain different substituents on the coordinating backbone, different linkers between two [12]aneN(3) units and different N-methylation on the [12]aneN(3) units, have been synthesized and fully characterized. The catalytic activities of their metal complexes on the cleavage of RNA model phosphate 2-hydroxypropyl-p-nitrophenyl phosphate (HPNPP) varied with the structures of the ligands and metal ions. Click reactions afforded an efficient method to prepare a series of [12]aneN(3) ligands, however, the incorporation of triazole moieties reduced the catalytic activities due to their coordination with metal ions and the strong inhibition from the triflate counter ion. Dinuclear zinc(II) complexes containing an m-xylyl bridge showed higher catalytic activities with synergistic effects up to 700-fold. Copper(II) complexes with the ligands without triazole moieties proved to be highly reactive and showed strong cooperativity between the two copper(II) ions. In terms of k(2), dinuclear complexes Zn(2)-3b, Zn(2)-3d, Zn(2)-4b, and Cu(2)-4b afforded activities of 7.9 × 10(5), 3.9 × 10(4), 9.0 × 10(4), and 8.1 × 10(4)-fold higher than that of methoxide. The ortho arrangement of the two [12]aneN(3) units and the presence of 5- or 2-positioned substituents in the benzene ring as well as N-methylation of [12]aneN(3) units greatly reduced the catalytic activities due to the steric effects. These results clearly indicate that the structures of the linker between two [12]aneN(3) units play very important role in their catalytic synergistic effects.
authors: College of Chemistry, Beijing Normal University, Xinjiekouwai Street 19, Beijing, 100875, China.
authors: Zhi-Fo
authors: ZF
authors: Guo
authors: Hao
authors: H
authors: Yan
authors: Zhi-Fen
authors: ZF
authors: Li
authors: Zhong-Lin
authors: ZL
authors: Lu
mesh_terms: D002384:Catalysis; D060326:Chemistry Techniques, Synthetic; D003300:Copper / Q000737:chemistry; D008024:Ligands; D008745:Methylation; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010755:Organophosphates; D009943:Organophosphorus Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D012313:RNA / Q000737:chemistry*; D013237:Stereoisomerism; D015032:Zinc / Q000737:chemistry
chemical_list: C436487:2-(hydroxypropyl)-4-nitrophenyl phosphate; D008024:Ligands; D009942:Organometallic Compounds; D010755:Organophosphates; D009943:Organophosphorus Compounds; D012313:RNA; D003300:Copper; D015032:Zinc