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991.
Ravindra P. Jumde Melissa Guardigni Robin M. Gierse Alaa Alhayek Di Zhu Zhoor Hamid Sandra Johannsen Walid A. M. Elgaher Philipp J. Neusens Christian Nehls Jrg Haupenthal Norbert Reiling Anna K. H. Hirsch 《Chemical science》2021,12(22):7775
Target-directed dynamic combinatorial chemistry (tdDCC) enables identification, as well as optimization of ligands for un(der)explored targets such as the anti-infective target 1-deoxy-d-xylulose-5-phosphate synthase (DXPS). We report the use of tdDCC to first identify and subsequently optimize binders/inhibitors of the anti-infective target DXPS. The initial hits were also optimized for their antibacterial activity against E. coli and M. tuberculosis during subsequent tdDCC runs. Using tdDCC, we were able to generate acylhydrazone-based inhibitors of DXPS. The tailored tdDCC runs also provided insights into the structure–activity relationship of this novel class of DXPS inhibitors. The competition tdDCC runs provided important information about the mode of inhibition of acylhydrazone-based inhibitors. This approach holds the potential to expedite the drug-discovery process and should be applicable to a range of biological targets.Target-directed dynamic combinatorial chemistry was used for hit-identification and subsequent hit-optimization for the anti-infective target 1-deoxy-d-xylulose-5-phosphate synthase resulting in novel inhibitors with low micromolar affinities. 相似文献
992.
We prove a conjecture dating back to a 1978 paper of D.R. Musser [11], namely that four random permutations in the symmetric group Sn generate a transitive subgroup with probability for some independent of n, even when an adversary is allowed to conjugate each of the four by a possibly different element of . In other words, the cycle types already guarantee generation of a transitive subgroup; by a well known argument, this implies generation of An or except for probability as . The analysis is closely related to the following random set model. A random set is generated by including each independently with probability . The sumset is formed. Then at most four independent copies of are needed before their mutual intersection is no longer infinite. © 2015 Wiley Periodicals, Inc. Random Struct. Alg., 49, 409–428, 2016 相似文献
993.
Eric A. Carlen Elliott H. Lieb Robin Reuvers 《Communications in Mathematical Physics》2016,344(3):655-671
Unlike bosons, fermions always have a non-trivial entanglement. Intuitively, Slater determinantal states should be the least entangled states. To make this intuition precise we investigate entropy and entanglement of fermionic states and prove some extremal and near extremal properties of reduced density matrices of Slater determinantal states. 相似文献
994.
Simultaneous X‐ray fluorescence and scanning X‐ray diffraction microscopy at the Australian Synchrotron XFM beamline
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Michael W. M. Jones Nicholas W. Phillips Grant A. van Riessen Brian Abbey David J. Vine Youssef S. G. Nashed Stephen T. Mudie Nader Afshar Robin Kirkham Bo Chen Eugeniu Balaur Martin D. de Jonge 《Journal of synchrotron radiation》2016,23(5):1151-1157
Owing to its extreme sensitivity, quantitative mapping of elemental distributions via X‐ray fluorescence microscopy (XFM) has become a key microanalytical technique. The recent realisation of scanning X‐ray diffraction microscopy (SXDM) meanwhile provides an avenue for quantitative super‐resolved ultra‐structural visualization. The similarity of their experimental geometries indicates excellent prospects for simultaneous acquisition. Here, in both step‐ and fly‐scanning modes, robust, simultaneous XFM‐SXDM is demonstrated. 相似文献
995.
Fen Su Dr. Juan Zou Xiaokang Lv Fengfei Lu Yijie Long Kun Tang Benpeng Li Prof. Dr. Huifang Chai Prof. Xingxing Wu Prof. Dr. Yonggui Robin Chi 《Angewandte Chemie (International ed. in English)》2023,62(23):e202303388
The development of catalyst-controlled methods for direct functionalization of two distinct C−H bonds represents an appealing approach for C−C formations in synthetic chemistry. Herein, we describe an organocatalytic approach for straightforward acylation of C(sp3)−H bonds employing readily available aldehyde as “acyl source” involving dehydrogenative coupling of aldehydes with ether, amine, or benzylic C(sp3)−H bonds. The developed method affords a broad range of ketones under mild conditions. Mechanistically, simple ortho-cyanoiodobenzene is essential in the oxidative radical N-heterocyclic carbene catalysis to give a ketyl radical and C(sp3) radical through a rarely explored intermolecular hydrogen atom transfer pathway, rendering the acylative C−C formations in high efficiency under a metal- and light-free catalytic conditions. Moreover, the prepared products show promising anti-bacterial activities that shall encourage further investigations on novel agrochemical development. 相似文献
996.
Dr. Victorino Vallejos González Justin Kahle Christopher Hüßler Dr. Robin Heckershoff Prof. Dr. A. Stephen K. Hashmi Dr. Bernhard Birenheide Dr. Adrian Hauser Prof. Dr. Joachim Podlech 《European journal of organic chemistry》2023,26(33):e202300545
The synthesis of three penta- and three hexahelicenes containing two terminal thiophene units is described. The syntheses of pentahelicenes consist of 1,4-bisalkynylation of a benzene precursor and double Suzuki coupling in 2,3-position to introduce thiophene units. The ortho,ortho’ fusion yielding the final products was achieved with Fürstner's protocol using platinum(II) chloride or JohnPhos-complexed gold(I) as catalysts. A similar approach to hexahelicenes started with a naphthalene derivative, where 2,7-bisalkynylation and subsequent double Suzuki coupling with thiophene-2-boronic acid at 1,8-position furnished precursors, in which ortho,ortho’ fusion to the respective hexahelicenes was achieved with platinum(II) chloride or, favourably, with indium(III) chloride. UV/Vis spectra and cyclic voltammograms were recorded for all helicenes and HOMO/LUMO gaps were calculated with DFT methods. 相似文献
997.
Hannah Wineinger Dr. Volodymyr Smetana Ethan Hiti Prof. Dr. Glib Baryshnikov Dr. Fengrui Qu Prof. Dr. Hans Ågren Prof. Dr. Anja-Verena Mudring Prof. Dr. Robin D. Rogers 《欧洲无机化学杂志》2023,26(31):e202300450
Using Ce(III) as both a representative lanthanide and actinide analog, the ability of mixtures of acidic and basic azoles to allow direct access to homoleptic N-donor f-element complexes in one pot reactions from hydrated salts as starting materials was examined by reacting mixtures of 4-amino-1,2,4-triazole (4-NH2-1,2,4-Triaz), 5-amino-tetrazole (5-NH2-HTetaz), and 1,2,3-triazole (1,2,3-HTriaz) in 1 : 1 and 1 : 3 ratios with CeCl3 ⋅ 7H2O, [C2mim]3[CeCl6] ([C2mim]+=1-ethyl-2-methylimidazolium), and Ce(NO3)3 ⋅ 6H2O. Although unsuccessful in our goal, structural analysis revealed that neutral 4-NH2-1,2,4-Triaz is structure directing via η2μ2κ2 bridging, with the formation of the dinuclear complexes [Ce2Cl2(μ2-4-NH2-1,2,4-Triaz)4(H2O)8]Cl4 ⋅ 4H2O, [Ce2(μ2-4-NH2-1,2,4-Triaz)4(4-NH2-1,2,4-Triaz)2(Cl)6], and [4-NH2-1,2,4-HTriaz][Ce2(μ2-4-NH2-1,2,4-Triaz)2(μ2-NO3)(NO3)6(H2O)2]. When the synthetic conditions favored hydrolysis, the hexanuclear Ce(III) complex [Ce6(μ3-O)4(μ3-OH)2(μ3-Cl)2(Cl)6(μ2-4-NH2-1,2,4-Triaz)12] ⋅ 7H2O was isolated. This unexpected hydrolysis product represents the first example of a high nuclearity lanthanide complex where all Ln atoms are pairwise connected through 12 N-donor ligands or 12 neutral bridging ligands of any type, a rare example of incorporation of non-oxo coordinating anions in the M6X8 core, and the first reported Ce(III) hexanuclear complex of this type. 相似文献
998.
Busch GK Tate EW Gaffney PR Rosivatz E Woscholski R Leatherbarrow RJ 《Chemical communications (Cambridge, England)》2008,(29):3369-3371
We report an effective strategy for generating N-terminal cysteinyl proteins by proteolytic cleavage using the enzyme 3C pro, suitable for a wide range of applications via native chemical ligation. 相似文献
999.
1000.
Bon RS Sprenkels NE Koningstein MM Schmitz RF de Kanter FJ Dömling A Groen MB Orru RV 《Organic & biomolecular chemistry》2008,6(1):130-137
Alkylation and oxidation of 2H-2-imidazolines, followed by regioselective deprotection, thionation and microwave-assisted Liebeskind-Srogl reaction, efficiently led to 2-aryl-2-imidazolines as new analogues of p53-hdm2 interaction inhibitors (Nutlins). 相似文献