Synthesis and characterisation of polymerisable photochromic spiropyrans: towards photomechanical biomaterials
摘要:
A methodology for the synthesis of novel polymerisable spiropyrans with photomechanical properties suitable for subsequent copolymerisation with either vinyl or acrylate-based biomaterials is described. UV-vis spectroscopic characterisation of photoisomerism shows that photochromic behaviour with respect to related non-polymerisable compounds is retained and is solvent dependent. In acetone, conventional spiropyran-merocyanine photochromism is observed for nitro-spiropyran derivatives, whereas in dichloromethane both nitro-spiropyrans and spiropyrans isomerise to merocyanines which rapidly form H-aggregates. The monomers were designed such that an alkyl spacer of variable length, both electronically and sterically, separates the polymerisable moiety from the photochromic core and allows steric aspects of the resulting photomechanical behaviour to be explored. (c) 2006 Elsevier Ltd. All rights reserved.
Preparation of cyclic imides from alkene-tethered amides: application of homogeneous Cu(<scp>ii</scp>) catalytic systems
作者:Zhenghui Liu、Peng Wang、Hualin Ou、Zhenzhong Yan、Suqing Chen、Xingxing Tan、Dongkun Yu、Xinhui Zhao、Tiancheng Mu
DOI:10.1039/c9ra10422d
日期:——
A Cu-based homogeneous catalytic system was proposed for the preparation of imides from alkene-tethered amides. Here, O2 acted as a terminal oxidant and a cheap and easily available oxygen source. The cleavage of CC bonds and the formation of C–N bonds were catalyzed by Cu(II) salts with proper nitrogen-containing ligands under 100 °C. The synthesis approach has potential applications in pharmaceutical
提出了一种基于铜的均相催化体系,用于从烯烃束缚酰胺制备酰亚胺。在这里,O 2充当末端氧化剂和廉价且容易获得的氧源。在 100 °C 下,具有适当含氮配体的 Cu( II ) 盐催化C C 键的断裂和 C-N 键的形成。该合成方法在药物合成中具有潜在的应用。此外,放大实验证实了实际适用性。
Vitamin D derivative with substituent at the 2.beta.-position
申请人:Chugai Seiyaku Kabushiki Kaisha
公开号:US05877168A1
公开(公告)日:1999-03-02
A 1.alpha.-hydroxy-vitamin D derivative represented by formula (I): ##STR1## wherein R.sub.1 represents a hydrogen atom or a hydroxyl group; and R.sub.2 represents a straight-chain or branched lower alkyl, lower alkenyl or lower alkynyl group, which is substituted with a hydroxyl group, a halogen atom, a cyano group, a lower alkoxy group, an amino group or an acylamino group, is disclosed. The compound exhibits calcium metabolism regulating activity and differentiation stimulating activity on tumor cells, etc. and is useful as a treating agent for diseases caused by abnormal calcium metabolism, such as osteoporosis and osteomalacia, or as an antitumor agent.
The total synthesis of (-)-trans-kumausyne has been accomplished in an enantiospecific fashion starting from an L-arabinose derivative. The key step is the stereoselective formation of the substituted tetrahydrofuran via novel cyclization of the beta-silyl cation intermediate, generated by the addition of allylsilane to di-O-isopropylidene-aldehydo-arabinose in the presence of boron trifluoride etherate.
Synthesis and characterisation of polymerisable photochromic spiropyrans: towards photomechanical biomaterials
作者:Colin P. McCoy、Louise Donnelly、David S. Jones、Sean P. Gorman
DOI:10.1016/j.tetlet.2006.11.110
日期:2007.1
A methodology for the synthesis of novel polymerisable spiropyrans with photomechanical properties suitable for subsequent copolymerisation with either vinyl or acrylate-based biomaterials is described. UV-vis spectroscopic characterisation of photoisomerism shows that photochromic behaviour with respect to related non-polymerisable compounds is retained and is solvent dependent. In acetone, conventional spiropyran-merocyanine photochromism is observed for nitro-spiropyran derivatives, whereas in dichloromethane both nitro-spiropyrans and spiropyrans isomerise to merocyanines which rapidly form H-aggregates. The monomers were designed such that an alkyl spacer of variable length, both electronically and sterically, separates the polymerisable moiety from the photochromic core and allows steric aspects of the resulting photomechanical behaviour to be explored. (c) 2006 Elsevier Ltd. All rights reserved.
Attractant pheromones of coleoptera. Communication 1. Simple synthesis of exo- and endo-brevicomins using the oxy-cope rearrangement
作者:�. P. Serebryakov、G. D. Gamalevich、R. I. Shekhtman