- Copper-mediated ortho C–H primary amination of anilines
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We report herein a copper-mediated ortho C–H primary amination of anilines by using cheap and commercially available benzophenone imine as the amination reagent. The protocol show good functional group tolerance and heterocyclic compatibility. Late-stage diversification of drugs demonstrate the synthetic utility of this protocol.
- Cheng, Tai-Jin,Wang, Xing,Xu, Hui,Dai, Hui-Xiong
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- Copper-catalyzed regioselective 2-amination of o-haloanilides with aqueous ammonia
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An efficient Cu(II)-vasicine catalytic system has been developed for intramolecular C[sbnd]N bond formation. In this way, regioselective 2-amination of o-haloanilides with aqueous ammonia in EtOH has been achieved. This strategy provides several advantages, such as good regioselectivity, high yields and functional group tolerance.
- Tang, Yan-Ling,Li, Mei-Ling,Gao, Jin-Chun,Sun, Yun,Qu, Lu,Huang, Feng,Mao, Ze-Wei
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supporting information
(2021/04/02)
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- Investigation of dioxygen activation by copper(ii)-iminate/aminate complexes
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The activation of dioxygen by metal ions is critical in chemical and bio-chemical processes. A scientific challenge is the elucidation of the activation site of dioxygen in some copper metalloproteins, which is either the metal center or the substrate. In an effort to address this challenge, we prepared a series of new copper(ii) complexes (1·2H2O, 2·CH3OH, 3) with bio-inspired amidate ligands and investigated their activity towards dioxygen activation. The secondary amine group ligated to copper(ii) of the complex 1·2H2O in methyl alcohol is oxidized (2e?) by air dioxygen in a stepwise fashion to an imine group, affording complex 2. The copper(ii) complex 2 in methyl alcohol induces the 4e? oxidation by air dioxygen of the imine functionality ligated to copper(ii) to an azinate group, resulting in the isolation of a dinuclear azinate copper(ii) compound (4). Experimental and computational studies, including X-band c. w. EPR, UV-vis and ESI-MS spectroscopy and density functional theory computations, indicate a direct attack of the dioxygen on the-HC═N-group ligated to copper(ii), and a possible mechanism of the oxidation of the-HC═N-functionality ligated to copper(ii) to an azinate group is provided. This unprecedented activation of dioxygen by a copper substrate paves the way for further exploration of the O2 activation mechanisms in enzymes and the development of effective catalysts in O2-involved green organic synthesis.
- Papanikolaou, Michael G.,Hadjithoma, Sofia,Chatzikypraiou, Dimitra S.,Papaioannou, Dionysios,Drouza, Chryssoula,Tsipis, Athanassios C.,Miras, Haralampos N.,Keramidas, Anastasios D.,Kabanos, Themistoklis A.
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p. 16242 - 16254
(2018/11/30)
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- Liposome-based gene delivery systems containing a steroid derivative: computational and small angle X-ray diffraction study
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In this study, the structural properties and the phase behaviour of mixed composition neutral liposomes containing a functionalized steroid are reported. With the aim to design neutral liposomes able to coordinate cations and to complex DNA, we synthesized cholesteryl-2-(picolinamido)-phenylcarbamate (CHOLp) containing an N-aryl picolinamide group as chelating agent linked to the steroid structure via a carbamate moiety. The phase behaviour of mixtures of the functionalized cholesterol (CHOLp) and dioleoyl-phosphatidylcholine (DOPC) was investigated by means of X-ray diffraction. Simultaneously, atomistic molecular dynamics simulations of DOPC/CHOLp bilayers as a function of CHOLp molar fractions were carried out to investigate the specific effects of the polar steroid on the structural and dynamic properties of these zwitterionic bilayers. The molecular modelling studies have been performed both in absence and in presence of bivalent cations salts in order to assess the CHOLp ability to coordinate metal ions. The results show good stability of the resulting DOPC/CHOLp bilayers which is improved by the presence of salt. This is particularly evident at low amount of CHOLp where a high order of the lipid tails can be observed, suggesting stabilization of the corresponding DOPC liposomes. This feature can be ascribed to the polar nature and structural properties of the ligand. In fact, due to the presence of the aromatic moieties, CHOLp combines two different behaviours, namely a propensity to realize both intermolecular π-stacking interactions and cation-π bonding mainly evident in CaCl2. The last feature confirms for CHOLp a role as a cation-mediated complexation agent for DNA. The X-ray diffraction data on the capability of DOPC/CHOLp liposomes to complex DNA was also reported.
- Galeazzi,Bruni,Crucianelli,Laudadio,Marini,Massaccesi,Mobbili,Pisani
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p. 54070 - 54078
(2015/07/01)
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