Conversion of acetonitrile into acetamide in the co-ordination spheres of cis- and trans-M II (amine)2(M = Pt or Pd). Solution and crystal structural studies
摘要:
The preparation and solution behaviour, of mono- and bis-acetonitrile complexes of cis-[Pt(NH3)(2)Cl-2], [Pt(en)Cl-2] (en = ethane-1,2-diamine) and trans-[Pt(NH3)(2)Cl-2] has' been investigated. The nitrile Complexes are hydrolysed to acetamidate, acetamidate-bridged and mixed acetamidate-acetonitrile species. It is shown that an essential feature of monomeric acetamidate complexes with cis configuration is their tendency to dimerize to dinuclear platinum compounds having bridging amidate ligands. The resulting dimers undergo a facile head-to-tail to head-to-head rearrangement without any detectable. intermediate. Solution studies df the mononitrile complex trans-[Pt(NH3)(2)(MeCN)(OH)](+) at around neutral pH reveal the formation of trans-[Pt(NH3)(2)(MeCN)(NHCOMe)](+), suggesting a preceding ligand exchange. The reactions of platinum with MeCN are compared with those of the kinetically labile palladium. The nitrile complex cis-[Pt(NH3)(2)(MeCN)Cl]ClO4 and the mixed-ligand complex trans-[Pt(NH3)(2)(MeCN)(NHCOMe)]ClO4 were characterized by X-ray crystallography: cis-[Pt(NH3)(2)-(MeCN)Cl]ClO4, monoclinic, space group P2(1)/c, a = 10.618(10), b = 10.625(8), c = 9.176(7) Angstrom, beta = 111.20(6)degrees, Z = 4; trans-[Pt(NH3)(2)(MeCN)(NHCOMe)]ClO4, monoclinic, space-group P2(1)/c, a = 8.601 (6), b = 19.508(19), c = 7.625(4) Angstrom, beta = 115.29(5)degrees, Z = 4.
Using a Build-and-Click Approach for Producing Structural and Functional Diversity in DNA-Targeted Hybrid Anticancer Agents
作者:Song Ding、Xin Qiao、Gregory L. Kucera、Ulrich Bierbach
DOI:10.1021/jm301278c
日期:2012.11.26
An efficient screening method was developed for functionalized DNA targeted platinum-containing hybrid anticancer agents based on metal mediated amine-to-nitrile addition, a form of "click" chemistry. The goal of the study was in generate platinum-acridine agents for their use as cytotoxic "warheads" in targeted and multifunctional therapies. This was achieved by introducing hydroxl, carboxylic acid, and azide functionalities in the acridine linker moiety and by varying the nonleaving groups attached to platinum. The assay, which was based on microscale reactions between 6 platinum-nitrile complexes and 10 acridine derivatives, yielded a small library of 60 platinum-acridines. Reactions were monitored, and product mixtures were quantitatively analyzed by automated in-line high-performance liquid chromatography-electrospray mass spectrometry (LC-ESMS) analysis and subjected to cell viability screening using a nonradioactive cell proliferation assay. The new prescreening methodology proves to be a powerful tool for establishing structure-activity relationships and for identifying target compounds.