排序方式: 共有11条查询结果,搜索用时 31 毫秒
1.
Varinder K. Aggarwal Nekane Barbero Eoghan M. McGarrigle Greg Mickle Raquel Navas José Ramón Suárez Matthew G. Unthank Muhammad Yar 《Tetrahedron letters》2009,50(26):3482-2545
Ellman’s chiral auxiliary is converted into tert-butylsulfinyl chloride on sulfinamide deprotection with HCl and can be recovered in high yield upon treatment with ammonia. The enantiopure auxiliary can be obtained by trapping the sulfinyl chloride with a chiral alcohol followed by treatment of the resulting sulfinate ester with LiNH2. 相似文献
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MK Hossain-Ibrahim K Rezajooi JK MacNally MRJ Mason AR Lieberman PN Anderson 《BMC neuroscience》2006,7(1):8-21
Background
Inflammation around cell bodies of primary sensory neurons and retinal ganglion cells enhances expression of neuronal growth-associated genes and stimulates axonal regeneration. We have asked if inflammation would have similar effects on corticospinal neurons, which normally show little response to spinal cord injury. Lipopolysaccharide (LPS) was applied onto the pial surface of the motor cortex of adult rats with or without concomitant injury of the corticospinal tract at C4. Inflammation around corticospinal tract cell bodies in the motor cortex was assessed by immunohistochemistry for OX42 (a microglia and macrophage marker). Expression of growth-associated genes c-jun, ATF3, SCG10 and GAP-43 was investigated by immunohistochemistry or in situ hybridisation. 相似文献4.
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Meyer-Schuster rearrangements of propargylic alcohols take place readily at room temperature in toluene with 1-2 mol % PPh(3)AuNTf(2), in the presence of 0.2 equiv of 4-methoxyphenylboronic acid or 1 equiv of methanol. Good to excellent yields of enones can be obtained from secondary and tertiary alcohols, with high selectivity for the E-alkene in most cases. A one-pot procedure for the conversion of primary propargylic alcohols into β-arylketones was also developed, via Meyer-Schuster rearrangement followed by Pd-catalayzed addition of a boronic acid. 相似文献
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The nucleide 73Kr has been identified by on-line mass separation as a precursor of β-delayed proton emission. The proton branch is (6.8 ±1.2) × 10−3 proton/decay. The protons populate the ground state and also the first excited 2+ state at 866 keV in 72Se with a relative intensity of (35±9) %. The value of QEC−Bp, where Bp is the proton separation energy for the nucleus 73Br, is found to be 4.85 ±0.30 MeV based on the fraction of proton events preceded by positron decay. 相似文献
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Alan Ironmonger Mark Shipton Fiona Slater Pete Szeto Matthew G. Unthank François-René Alexandre Catherine Caillet Cyril B. Dousson 《Tetrahedron letters》2018,59(22):2154-2156
A highly diastereoselective chloride-mediated dynamic kinetic resolution at phosphorus has been developed to access a key intermediate in the synthesis of GSK2248761A. This procedure utilises a soluble chloride source and a cheap readily available chiral auxiliary. The practicality of this transformation is demonstrated on a multi-gram scale. 相似文献
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Wood BR Langford SJ Cooke BM Lim J Glenister FK Duriska M Unthank JK McNaughton D 《Journal of the American Chemical Society》2004,126(30):9233-9239
Resonance Raman spectra of beta-hematin and hemin are reported for a range of excitation wavelengths including 406, 488, 514, 568, 633, 780, 830, and 1064 nm. Dramatic enhancement of A(1g) modes (1570, 1371, 795, 677, and 344 cm(-1)), ring breathing modes (850-650 cm(-1)), and out-of-plane modes including iron-ligand modes (400-200 cm(-1)) were observed when irradiating with 780- and 830-nm laser excitation wavelengths for beta-hematin and to a lesser extent hemin. Absorbance spectra recorded during the transformation of hemin to beta-hematin showed a red-shift of the Soret and Q (0-1) bands, which has been interpreted as excitonic coupling resulting from porphyrin aggregation. A small broad electronic transition observed at 867 nm was assigned to a z-polarized charge-transfer transition d(xy) --> e(g)(pi). The extraordinary band enhancement observed when exciting with near-infrared excitation wavelengths in beta-hematin when compared to hemin is explained in terms of an aggregated enhanced Raman scattering hypothesis based on the intermolecular excitonic interactions between porphyrinic units. This study provides new insight into the electronic structure of beta-hematin and therefore hemozoin (malaria pigment). The results have important implications in the design and testing of new anti-malaria drugs that specifically interfere with hemozoin formation. 相似文献
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Diphenyl vinyl sulfonium salt and chiral amido-ketones undergo highly diastereoselective epoxy-annulation reactions in good yield. The use of a chiral vinyl sulfonium salt dominates the stereochemical outcome of the annulation reaction (reagent control is greater than substrate control), and this has allowed the kinetic resolution of racemic amido-ketones to be achieved. 相似文献
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Sven P. Fritz Zulfiquar Ali Matthew G. Unthank Eoghan M. McGarrigle Varinder K. Aggarwal 《Helvetica chimica acta》2012,95(12):2384-2398
A versatile and simple method is reported for the synthesis of bicyclic epoxide and aziridine? fused heterocycles (up to 98% yield, up to 96 : 4 er or up to 15 : 1 dr), using a tandem Michael addition/Johnson? Corey? Chaykovsky annulation approach. A new chiral (2‐bromoethyl)sulfonium reagent is described, based on an easily available chiral sulfide; it promotes or enhances stereoselectivity in the reaction. 相似文献