The present invention relates to the use of certain osmium containing complexes such as cytotoxic agents particularly for the treatment of cancer. There is also provided novel osmium containing complexes, as well as pharmaceutical formulations comprising such complexes.
Iron-Catalyzed 1,4-Addition of α-Olefins to Dienes
作者:Benoît Moreau、Jessica Y. Wu、Tobias Ritter
DOI:10.1021/ol802524r
日期:2009.1.15
A new intermolecular, stereo- and regioselective iron-catalyzed 1,4-addition of α-olefins to 1,3-dienes using as low as 1 mol % of an iminopyridine−ferrous chloride complex was developed. Importantly, both double bonds of the linear 1,4-diene addition products are obtained with absolute stereocontrol.
Chiral oxaziridines in the enantioselective synthesis of isoxazolidines
作者:Luigino Troisi、Sara De Lorenzis、Marilena Fabio、Francesca Rosato、Catia Granito
DOI:10.1016/j.tetasy.2008.09.016
日期:2008.10
The stereoselective synthesis of oxaziridines with three stereogenic centres is presented in this paper. The chirality is provided by asymmetric induction, and a possible mechanism for the induced stereoselectivity is also discussed. These small heterocycles undergo the [3+2] cycloaddition reaction with aryl ethenes to afford enantiomerically pure isoxazolidines of controlled configurations. This class
Atom transfer polymerisation of methyl methacrylate: use of chiral aryl/alkyl pyridylmethanimine ligands; with copper(I) bromide and as structurally characterised chiral copper(I) complexes
作者:David M. Haddleton、David J. Duncalf、Dax Kukulj、Alex M. Heming、Andrew J. Shooter、Andrew J. Clark
DOI:10.1039/a800467f
日期:——
The use ofchiral catalysts in the living radical polymerisation of methyl methacrylate via atom transfer polymerisation (ATP) has been investigated in an effort to control the stereochemistry of the polymer backbone. Two enantiomerically pure chiral catalysts have been prepared and used in the ATP of methyl methacrylate: the structurally characterised complex, bis[N-(1-phenylethyl)-2-pyridylmethanimine]copper() tetrafluoroborate, [Cu(C14H14N2)2 ][BF4 ], and the reaction product of copper() bromide with N-(1-cyclohexylethyl)-2-pyridylmethanimine, [Cu(C14H20N2)2 ][Br]. Both catalysts were found to be suitable for the ATP of methyl methacrylate in conjunction with either ethyl 2-bromo-2-methylpropanoate in xylene at 90 °C or 4-methoxybenzenesulfonyl chloride in diphenyl ether at 90 °C. The system yields polymer of relatively narrow polydispersity; however, the use of these chiral catalysts did not significantly affect the stereochemistry of the polymer backbone. This may be due to the chiral centre being too distant from the propagating site to exert any influence over the monomer addition step, or that the reaction proceeds via a completely free-radical mechanism. This is, however, the first time a discrete, structurally characterised copper complex has been used as an effective ATP catalyst. The bond lengths of the complexed ligand indicate the oxidation state of the copper to be +1 in the complex.
为了控制聚合物骨架的立体化学,我们研究了手性催化剂在通过原子转移聚合(ATP)进行甲基丙烯酸甲酯活自由基聚合过程中的应用。我们制备了两种对映体纯手性催化剂,并将其用于甲基丙烯酸甲酯的 ATP:一种是具有结构特征的复合物双[N-(1-苯基乙基)-2-吡啶基甲基亚胺]四氟硼酸铜[Cu(C14H14N2)2 ][BF4],另一种是溴化铜与 N-(1-环己基乙基)-2-吡啶基甲基亚胺的反应产物[Cu(C14H20N2)2 ][Br]。研究发现,这两种催化剂都适用于甲基丙烯酸甲酯与二甲苯中的 2-溴-2-甲基丙酸乙酯(90 °C)或二苯醚中的 4-甲氧基苯磺酰氯(90 °C)的 ATP 反应。该体系产生的聚合物具有相对较窄的多分散性;然而,使用这些手性催化剂并不会对聚合物骨架的立体化学产生显著影响。这可能是由于手性中心距离传播位点太远,无法对单体加成步骤产生任何影响,也可能是由于反应完全通过自由基机理进行。不过,这是首次将结构上独立的铜络合物用作有效的 ATP 催化剂。络合配体的键长表明了络合物中铜的氧化态为 +1 。
Synthesis of optically active imidazopyridinium salts and the corresponding NHCs
作者:Michael A. Schmidt、Mohammad Movassaghi
DOI:10.1016/j.tetlet.2006.10.157
日期:2007.1
A convergent synthesis of chiral imidazo-[1,5-a]-pyridinium salts is described by facile introduction of a stereogenic center via the N2 substituent. Conversion of these opticallyactivesalts to the corresponding N-heterocyclic carbenes (NHCs) and their trapping with sulfur followed by optical activity measurements are discussed.
通过经由N 2取代基容易地引入立体异构中心来描述手性咪唑-[1,5- a ]-吡啶鎓盐的会聚合成。讨论了将这些旋光性盐转化为相应的N-杂环卡宾(NHC),并用硫将其捕获,然后进行旋光性测量。