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Katherine M. Byrd Chitra Subramanian Jacqueline Sanchez Hashim F. Motiwala Weiya Liu Prof. Mark S. Cohen Prof. Jeffrey Holzbeierlein Prof. Brian S. J. Blagg 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(20):6921-6931
Development of heat shock protein 90 (Hsp90) C‐terminal inhibitors has emerged as an exciting strategy for the treatment of cancer. Previous efforts have focused on modifications to the natural products novobiocin and coumermycin. Moreover, variations in both the sugar and amide moieties have been extensively studied, whereas replacements for the coumarin core have received less attention. Herein, 24 cores were synthesized with varying distances and angles between the sugar and amide moieties. Compounds that exhibited good anti‐proliferative activity against multiple cancer cell lines and Hsp90 inhibitory activity, were those that placed the sugar and amide moieties between 7.7 and 12.1 Å apart along with angles of 180°. 相似文献
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Marina Frank Dr. Mark D. Johnstone Prof. Dr. Guido H. Clever 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(40):14104-14125
This Review covers design strategies, synthetic challenges, host–guest chemistry, and functional properties of interlocked supramolecular cages. Some dynamic covalent organic structures are discussed, as are selected examples of interpenetration in metal–organic frameworks, but the main focus is on discrete coordination architectures, that is, metal‐mediated dimers. Factors leading to interpenetration, such as geometry, flexibility and chemical makeup of the ligands, coordination environment, solvent effects, and selection of suitable counter anions and guest molecules, are discussed. In particular, banana‐shaped bis‐pyridyl ligands together with square‐planar metal cations have proven to be suitable building blocks for the construction of interpenetrated double‐cages obeying the formula [M4L8]. The peculiar topology of these double‐cages results in a linear arrangement of three mechanically coupled pockets. This allows for the implementation of interesting guest encapsulation effects such as allosteric binding and template‐controlled selectivity. In stimuli‐responsive systems, anionic triggers can toggle the binding of neutral guests or even induce complete structural conversions. The increasing structural and functional complexity in this class of self‐assembled hosts promises the construction of intelligent receptors, novel catalytic systems, and functional materials. 相似文献
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Nickel(II) meso‐Hydroxyporphyrin Complexes Revisited: Palladium‐Catalysed Synthesis,Electronic Structures of Derived Oxy Radicals,and Oxidative Coupling to a Dioxoporphodimethene Dyad 下载免费PDF全文
Dr. Louisa J. Esdaile Dr. Llew Rintoul Mean See Goh Khalissa Merahi Dr. Nathalie Parizel Dr. R. Mark Wellard Dr. Sylvie Choua Prof. Dennis P. Arnold 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(10):3430-3446
We report the synthesis and characterisation of new examples of meso‐hydroxynickel(II) porphyrins with 5,15‐diphenyl and 10‐phenyl‐5,15‐diphenyl/diaryl substitution. The OH group was introduced by using carbonate or hydroxide as nucleophile by using palladium/phosphine catalysis. The NiPor?OHs exist in solution in equilibrium with the corresponding oxy radicals NiPor?O.. The 15‐phenyl group stabilises the radicals, so that the 1H NMR spectra of {NiPor?OH} are extremely broad due to chemical exchange with the paramagnetic species. The radical concentration for the diphenylporphyrin analogue is only 1 %, and its NMR line‐broadening was able to be studied by variable‐temperature NMR spectroscopy. The EPR signals of NiPor?O. are consistent with somewhat delocalised porphyrinyloxy radicals, and the spin distributions calculated by using density functional theory match the EPR and NMR spectroscopic observations. Nickel(II) meso‐hydroxy‐10,20‐diphenylporphyrin was oxidatively coupled to a dioxo‐terminated porphodimethene dyad, the strongly red‐shifted electronic spectrum of which was successfully modelled by using time‐dependent DFT calculations. 相似文献
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Mark Weinstein 《Foundations of Chemistry》2016,18(3):195-212
The periodic table may be seen as the most successful example of inquiry in the history of science, both in terms of practical application and theoretic understanding. As such, it serves as a model for truth as it emerges from inquiry. This paper offers a sketch of a central moment in the history of chemistry that illustrates an intuitive metamathematical construction, a model of emerging truth (MET). The MET, reflecting the structure the surrounds the periodic table, attempts to capture the salient epistemological elements that warrant truth claims based on sets of models that are progressive in light of both empirical and theoretical advance seen over time. 相似文献
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