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Wenyu Wang Dr. Regina Cencic Dr. Luke Whitesell Prof. Dr. Jerry Pelletier Prof. Dr. John A. Porco Jr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(34):12006-12010
Synthesis of aza‐rocaglates, nitrogen‐containing analogues of the rocaglate natural products, is reported. The route features ESIPT‐mediated (3+2) photocycloaddition of 1‐alkyl‐2‐aryl‐3‐hydroxyquinolinones with the dipolarophile methyl cinnamate. A continuous photoflow reactor was utilized for photocycloadditions. An array of compounds bearing the hexahydrocyclopenta[b]indole core structure was synthesized and evaluated in translation inhibition assays. 相似文献
755.
Dr. Michael G. Walker Dr. Paul J. Jarman Dr. Martin R. Gill Dr. Xiaohe Tian Dr. Haslina Ahmad Dr. Pattubala A. N. Reddy Luke McKenzie Prof. Julia A. Weinstein Dr. Anthony J. H. M. Meijer Prof. Giuseppe Battaglia Prof. Carl G. W. Smythe Prof. Jim A. Thomas 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(17):5996-6000
Although metal‐ion‐directed self‐assembly has been widely used to construct a vast number of macrocycles and cages, it is only recently that the biological properties of these systems have begun to be explored. However, up until now, none of these studies have involved intrinsically photoexcitable self‐assembled structures. Herein we report the first metallomacrocycle that functions as an intracellular singlet oxygen sensitizer. Not only does this Ru2Re2 system possess potent photocytotoxicity at light fluences below those used for current medically employed systems, it offers an entirely new paradigm for the construction of sensitizers for photodynamic therapy. 相似文献
756.
Christopher Selleck Prof. James A. Larrabee Assoc. Prof. Jeffrey Harmer Assoc. Prof. Luke W. Guddat Dr. Nataša Mitić Waleed Helweh Prof. David L. Ollis Dr. Whitney R. Craig Prof. David L. Tierney Dr. Marcelo Monteiro Pedroso Prof. Gerhard Schenk 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(49):17704-17714
Antibiotic resistance has emerged as a major threat to global health care. This is largely due to the fact that many pathogens have developed strategies to acquire resistance to antibiotics. Metallo‐β‐lactamases (MBL) have evolved to inactivate most of the commonly used β‐lactam antibiotics. AIM‐1 is one of only a few MBLs from the B3 subgroup that is encoded on a mobile genetic element in a major human pathogen. Here, its mechanism of action was characterised with a combination of spectroscopic and kinetic techniques and compared to that of other MBLs. Unlike other MBLs it appears that AIM‐1 has two avenues available for the turnover of the substrate nitrocefin, distinguished by the identity of the rate‐limiting step. This observation may be relevant with respect to inhibitor design for this group of enzymes as it demonstrates that at least some MBLs are very flexible in terms of interactions with substrates and possibly inhibitors. 相似文献
757.
Luke J. Williams Dr. Yunas Bhonoah Dr. Luke A. Wilkinson Dr. James W. Walton 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(11):3650-3660
π-Coordination of aromatic molecules to metals dramatically alters their reactivity. For example, coordinated carbons become more electrophilic and C−H bonds of coordinated rings become more acidic. For many years, this change in reactivity has been used to trigger reactions that would not take place for uncoordinated arenes, however, there has been a recent resurgence in use of this technique, in part due to the development of catalytic reactions in which π-coordination is transient. In this Minireview, we describe the key reaction chemistry of arenes coordinated to a range of transition metals, including stereoselective reactions and industrially relevant syntheses. We also summarise outstanding examples of catalytic processes. Finally, we give perspectives on the future direction of the field, with respect to both reactions that are stoichiometric in activating metals and those employing catalytic metal. 相似文献
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All‐Inorganic Nanocrystals as a Glue for BiSbTe Grains: Design of Interfaces in Mesostructured Thermoelectric Materials
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Dr. Jae Sung Son Hao Zhang Dr. Jaeyoung Jang Dr. Bed Poudel Al Waring Luke Nally Prof. Dr. Dmitri V. Talapin 《Angewandte Chemie (International ed. in English)》2014,53(29):7466-7470
Nano‐ and mesostructuring is widely used in thermoelectric (TE) materials. It introduces numerous interfaces and grain boundaries that scatter phonons and decrease thermal conductivity. A new approach has been developed for the rational design of the interfaces in TE materials by using all‐inorganic nanocrystals (NCs) that serve as a “glue” for mesoscopic grains. For example, circa 10 nm Bi NCs capped with (N2H5)4Sb2Te7 chalcogenidometallate ligands can be used as an additive to BiSbTe particles. During heat treatment, NCs fill up the voids between particles and act as a “glue”, joining grains in hot‐pressed pellets or solution‐processed films. The chemical design of NC glue allowed the selective enhancement or decrease of the majority‐carrier concentration near the grain boundaries, and thus resulted in doped or de‐doped interfaces in granular TE material. Chemically engineered interfaces can be used as to optimize power factor and thermal conductivity. 相似文献
760.
Mechanism of Alkyne Alkoxycarbonylation at a Pd Catalyst with P,N Hemilabile Ligands: A Density Functional Study
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Luke Crawford Prof. David J. Cole‐Hamilton Prof. Eite Drent Prof. Michael Bühl 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(43):13923-13926
A detailed mechanism for alkyne alkoxycarbonylation mediated by a palladium catalyst has been characterised at the B3PW91‐D3/PCM level of density functional theory (including bulk solvation and dispersion corrections). This transformation, investigated via the methoxycarbonylation of propyne, involves a uniquely dual role for the P,N hemilabile ligand acting co‐catalytically as both an in situ base and proton relay coupled with a Pd0 centre, allowing for surmountable barriers (highest ΔG≠ of 22.9 kcal mol?1 for alcoholysis). This proton‐shuffle between methanol and coordinated propyne accounts for experimental requirements (high acid concentration) and reproduces observed regioselectivities as a function of ligand structure. A simple ligand modification is proposed, which is predicted to improve catalytic turnover by three orders of magnitude. 相似文献