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Proietti Silvestri I Andemarian F Khairallah GN Yap SW Quach T Tsegay S Williams CM O'Hair RA Donnelly PS Williams SJ 《Organic & biomolecular chemistry》2011,9(17):6082-6088
Silver acetylides and organic azides react under copper(I) catalysis to afford 1,4-disubstituted 1,2,3-triazoles. Mechanistic studies implicate a process involving transmetallation to copper acetylides prior to cycloaddition. This work demonstrates that silver acetylides serve as suitable precursors for entry into copper-mediated coupling reactions. This methodology allows the incorporation of volatile and difficult-to-handle acetylenes into the triazole core. 相似文献
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Dr. Abebe R. Woldu Pooya Talebi Asfaw G. Yohannes Jianyin Xu Xu-Dong Wu Dr. Samira Siahrostami Dr. Liangsheng Hu Prof. Xiao-Chun Huang 《Angewandte Chemie (International ed. in English)》2023,62(29):e202301621
Tin disulfide (SnS2) is a promising candidate for electrosynthesis of CO2-to-formate while the low activity and selectivity remain a great challenge. Herein, we report the potentiostatic and pulsed potential CO2RR performance of SnS2 nanosheets (NSs) with tunable S-vacancy and exposure of Sn-atoms or S-atoms prepared controllably by calcination of SnS2 at different temperatures under the H2/Ar atmosphere. The catalytic activity of S-vacancy SnS2 (Vs-SnS2) is improved 1.8 times, but it exhibits an exclusive hydrogen evolution with about 100 % FE under all potentials investigated in the static conditions. The theoretical calculations reveal that the adsorption of *H on the Vs-SnS2 surface is energetically more favorable than the carbonaceous intermediates, resulting in active site coverage that hinders the carbon intermediates from being adsorbed. Fortunately, the main product can be switched from hydrogen to formate by applying pulsed potential electrolysis benefiting from in situ formed partially oxidized SnS2−x with the oxide phase selective to formate and the S-vacancy to hydrogen. This work highlights not only the Vs-SnS2 NSs lead to exclusively H2 formation, but also provides insights into the systematic design of highly selective CO2 reduction catalysts reconstructed by pulsed potential electrolysis. 相似文献
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Tim Quach Sammi Tsegay Andrew J. Thompson Nikolay V. Kukushkin Dominic S. Alonzi Terry D. Butters Gideon J. Davies Spencer J. Williams 《Tetrahedron: Asymmetry》2012,23(13):992-997
3-O-α-d-Glucopyranosyl-swainsonine was originally proposed17 as a potential inhibitor of the mammalian enzyme endo-α-mannosidase, but its synthesis has not been reported. Herein we report the total synthesis of this enigmatic compound, utilizing a halide-ion catalysed glycosylation of a swainsonine lactam with a glucosyl iodide donor as the key step. The resulting inhibitor was evaluated as an inhibitor of human endo-α-mannosidase, and as a ligand for bacterial orthologs from Bacteroides thetaiotaomicron and Bacteroides xylanisolvens, including active-centre variants, although no evidence for binding or inhibition was observed. The surprising lack of binding was rationalized by using structural alignment with an endo-α-mannosidase inhibitor complex, which identified deleterious interactions with the swainsonine piperidine ring and an essential active site residue. 相似文献
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The conformational, structural and electronic properties of eight acylthiourea derivatives with the general form N-acyl-N′, N′-alkylthiourea have been investigated computationally at the MP2 level of theory and the 6-311G(d) basis set. Transition states between the four stable conformations were identified and characterized. There is a good correlation between the electron density at the bond critical point of each of the three C–N bonds present in the molecules, the calculated bond length, and the rotational barrier around these bonds. The calculations suggest the C(S)-N′ bond to have considerable double bond character which, according to analysis in terms of the Natural Bond Orbitals paradigm, can be attributed to a more favorable delocalization of the N′ lone pair into the antibonding π*(C=S) orbital than the lone pair on the other nitrogen. The influence of the various substituents on the structural and energetic features of the acylthiourea backbone is also investigated. 相似文献
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