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991.
992.
Wenjun Yang Bo Ling Bowen Hu Haolin Yin Prof. Dr. Jianyou Mao Prof. Dr. Patrick J. Walsh 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(1):167-172
An umpolung 1,4-addition of aryl iodides to enals promoted by cooperative (terpy)Pd/NHC catalysis was developed that generates various bioactive β,β-diaryl propanoate derivatives. This system is not only the first reported palladium-catalyzed arylation of NHC-bound homoenolates but also expands the scope of NHC-induced umpolung transformations. A diverse array of functional groups such as esters, nitriles, alcohols, and heterocycles are tolerated under the mild conditions. This method also circumvents the use of moisture-sensitive organometallic reagents. 相似文献
993.
Ge Huang Prof. Li Yang Qi Yin Zhi-Bin Fang Xiao-Jing Hu An-An Zhang Prof. Jun Jiang Prof. Tian-Fu Liu Prof. Rong Cao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(11):4415-4420
Although many ionic metal–organic frameworks (MOFs) have been reported, little is known about how the charge of the skeleton affects the properties of the MOF materials. Herein we report how the chemical stability of MOFs can be substantially improved through embedding electrostatic interactions in structure. A MOF with a cationic skeleton is impervious to extremely acidic, oxidative, reductive, and high ionic strength conditions, such as 12 m HCl (301 days), aqua regia (86 days), H2O2 (30 days), and seawater (30 days), which is unprecedented for MOFs. DFT calculations suggested that steric hinderance and the repulsive interaction of the cationic framework toward positively charged species in microenvironments protects the vulnerable bonds in the structure. Diverse functionalities can be bestowed by substituting the counterions of the charged framework with identically charged functional species, which broadens the horizon in the design of MOFs adaptable to a demanding environment with specific functionalities. 相似文献
994.
Dr. Ran Du Dr. Jan-Ole Joswig Dr. René Hübner Lin Zhou Dr. Wei Wei Prof. Yue Hu Prof. Dr. Alexander Eychmüller 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(21):8370-8377
Noble-metal aerogels (NMAs) have drawn increasing attention because of their self-supported conductive networks, high surface areas, and numerous optically/catalytically active sites, enabling their impressive performance in diverse fields. However, the fabrication methods suffer from tedious procedures, long preparation times, unavoidable impurities, and uncontrolled multiscale structures, discouraging their developments. By utilizing the self-healing properties of noble-metal aggregates, the freezing-promoted salting-out behavior, and the ice-templating effect, a freeze–thaw method is crafted that is capable of preparing various hierarchically structured noble-metal gels within one day without extra additives. In light of their cleanliness, the multi-scale structures, and combined catalytic/optical properties, the electrocatalytic and photoelectrocatalytic performance of NMAs are demonstrated, which surpasses that of commercial noble-metal catalysts. 相似文献
995.
Jin Chen Dr. Chun-Li Hu Xiao-Han Zhang Dr. Bing-Xuan Li Dr. Bing-Ping Yang Prof. Jiang-Gao Mao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(13):5419-5422
The first alkali-metal vanadium iodate fluoride, CsVO2F(IO3), with a novel 3D anionic framework, has been rationally designed and hydrothermally synthesized. The 3D [VO2F(IO3)]− framework in CsVO2F(IO3) is built from 0D Λ-shaped cis-[VO3F(IO3)2]4− polyanions via corner-sharing of oxo anions and bridging of the iodate groups. CsVO2F(IO3) displays both a strong second-harmonic generation (SHG) 1.1 times as strong as KTiOPO4 (KTP) under 2.05 μm laser radiation and high laser-induced damage threshold (LIDT) of 107.9 MW cm−2. This work provides a new route to design SHG crystals with stable 3D anionic structures from low-dimensional structural building units. 相似文献
996.
Congcong Pei Dr. Chao Liu Dr. You Wang Dan Cheng Rongxin Li Weikang Shu Chaoqi Zhang Wenli Hu Dr. Aihua Jin Dr. Yannan Yang Prof. Jingjing Wan 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(27):10923-10927
High-throughput metabolic analysis is of significance in diagnostics, while tedious sample pretreatment has largely hindered its clinic application. Herein, we designed FeOOH@ZIF-8 composites with enhanced ionization efficiency and size-exclusion effect for laser desorption/ionization mass spectrometry (LDI-MS)-based metabolic diagnosis of gynecological cancers. The FeOOH@ZIF-8-assisted LDI-MS achieved rapid, sensitive, and selective metabolic fingerprints of the native serum without any enrichment or purification. Further analysis of extracted serum metabolic fingerprints successfully discriminated patients with gynecological cancers (GCs) from healthy controls and also differentiated three major subtypes of GCs. Given the low cost, high-throughput, and easy operation, our approach brings a new dimension to disease analysis and classification. 相似文献
997.
Dr. Mingzhe Chen Dr. Jin Xiao Dr. Weibo Hua Dr. Zhe Hu Dr. Wanlin Wang Dr. Qinfen Gu Prof. Yuxin Tang Prof. Shu-Lei Chou Prof. Hua-Kun Liu Prof. Shi-Xue Dou 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(29):12174-12181
Titanium-based polyanions have been intensively investigated for sodium-ion batteries owing to their superior structural stability and thermal safety. However, their low working potential hindered further applications. Now, a cation and anion dual doping strategy is used to boost the redox potential of Ti-based cathodes of Na3Ti0.5V0.5(PO3)3N as a new cathode material for sodium ion batteries. Both the Ti3+/Ti4+ and V3+/V4+ redox couples are reversibly accessed, leading to two distinctive voltage platforms at ca. 3.3 V and ca. 3.8 V, respectively. The remarkably improved cycling stability (86.3 %, 3000 cycles) can be ascribed to the near-zero volume strain in this unusual cubic symmetry, which has been demonstrated by in situ synchrotron-based X-ray diffraction. First-principles calculations reveal its well-interconnected 3D Na diffusion pathways with low energy barriers, and the two-sodium-extracted intermediate NaTi0.5V0.5(PO3)3N is also a stable phase according to formation energy calculations. 相似文献
998.
Dr. Rahul Kisan Kawade Chaowei Hu Nikolas R. Dos Santos Noelle Watson Dr. Xinsong Lin Dr. Kenneth Hanson Dr. Igor V. Alabugin 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(34):14458-14463
3-Point annulations, or phenalenannulations, transform a benzene ring directly into a substituted pyrene by “wrapping” two new cycles around the perimeter of the central ring at three consecutive carbon atoms. This efficient, modular, and general method for π-extension opens access to non-symmetric pyrenes and their expanded analogues. Potentially, this approach can convert any aromatic ring bearing a -CH2Br or a -CHO group into a pyrene moiety. Depending upon the workup choices, the process can be directed towards either tin- or iodo-substituted product formation, giving complementary choices for further various cross-coupling reactions. The two-directional bis-double annulation adds two new polyaromatic extensions with a total of six new aromatic rings at a central core. 相似文献
999.
Mengmeng Zhang Dr. Jiajun Wang Hui Xue Dr. Jinfeng Zhang Prof. Dr. Shengjie Peng Dr. Xiaopeng Han Prof. Dr. Yida Deng Prof. Dr. Wenbin Hu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(42):18621-18625
Cu2O is a typical photoelectrocatalyst for sustainable hydrogen production, while the fast charge recombination hinders its further development. Herein, Ni2+ cations have been doped into a Cu2O lattice (named as Ni-Cu2O) by a simple hydrothermal method and act as electron traps. Theoretical results predict that the Ni dopants produce an acceptor impurity level and lower the energy barrier of hydrogen evolution. Photoelectrochemical (PEC) measurements demonstrate that Ni-Cu2O exhibits a photocurrent density of 0.83 mA cm−2, which is 1.34 times higher than that of Cu2O. And the photostability has been enhanced by 7.81 times. Moreover, characterizations confirm the enhanced light-harvesting, facilitated charge separation and transfer, prolonged charge lifetime, and increased carrier concentration of Ni-Cu2O. This work provides deep insight into how acceptor-doping modifies the electronic structure and optimizes the PEC process. 相似文献
1000.
Hui Hu Xiaoping Hu Prof. Yuanhong Liu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(43):19137-19141
An efficient copper-catalyzed regioselective C−H alkenylation and borylative alkylation of quinoline N-oxides with vinyl arenes in the presence of pinacol diborane has been developed. The reaction proceeds through the borylcupration of the vinyl arenes followed by nucleophilic attack of the resulting alkyl copper species to the quinoline N-oxides. Benzoquinone and KOtBu were identified as the necessary additives at the second step of the reaction that are crucial for the success of the reaction. A wide range of C2-functionalizaed quinolines were obtained with good functional group tolerance, which may find utilities in pharmaceuticals and synthetic chemistry. 相似文献