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991.
Weijie Yu Shengchun Wang Meng He Zhou Jiang Yi Yu Jinping Lan Jin Luo Pengjie Wang Prof. Xiaotian Qi Prof. Tao Wang Prof. Aiwen Lei 《Angewandte Chemie (International ed. in English)》2023,62(17):e202219166
Precisely introducing two similar functional groups into bulk chemical alkenes represents a formidable route to complex molecules. Especially, the selective activation of two electrophiles is in crucial demand, yet challenging for cross-electrophile-coupling. Herein, we demonstrate a redox-mediated electrolysis, in which aryl nitriles are both aryl radical precursors and redox-mediators, enables an intermolecular alkene 1,2-diarylation with a remarkable regioselectivity, thereby avoiding the involvement of transition-metal catalysts. This transformation utilizes cyanoarene radical anions for activating various aryl halides (including iodides, bromides, and even chlorides) and affords 1,2-diarylation adducts in up to 83 % yield and >20 : 1 regioselectivity with more than 80 examples, providing a feasible approach to complex bibenzyl derivatives. 相似文献
992.
Mingjie Zeng Changyue Yu Yibing Wang Jingjing Wang Jiang Wang Hong Liu 《Angewandte Chemie (International ed. in English)》2023,62(22):e202300424
We report a ligand-controlled CoII-catalyzed C(sp3)−C(sp3) coupling hydroalkylation for direct and β-selective synthesis of 2-deoxy-C-glycosides from glycals. This reaction proceeds by a radical pathway for alkyl halide activation and is β-selective through ligand control. This approach may inspire the development of further stereoselective coupling reactions with potential application in the field of carbohydrates. 相似文献
993.
Rémi Lavernhe Dr. Qian Wang Prof. Dr. Jieping Zhu 《Angewandte Chemie (International ed. in English)》2023,62(22):e202303537
Transition-metal-catalyzed [4+2] heteroannulation of α,β-unsaturated oximes and their derivatives with alkynes has been developed into a powerful strategy for the synthesis of pyridines. It nevertheless lacks regioselectivity when unsymmetrically substituted alkynes are used. We report herein the unprecedented synthesis of polysubstituted pyridines by a formal [5+1] heteroannulation of two readily accessible building blocks. A copper-catalyzed aza-Sonogashira cross-coupling between β,γ-unsaturated oxime esters and terminal alkynes affords ynimines, which, without isolation, undergo an acid-catalyzed domino reaction involving ketenimine formation, 6π-electrocyclization and aromatization to afford pyridines. Terminal alkynes served as a one-carbon donor to the pyridine core in this transformation. Di- through pentasubstituted pyridines are accessible with complete regioselectivity and excellent functional-group compatibility. The first total synthesis of anibamine B, an indolizinium alkaloid with potent antiplasmodial activity, was accomplished featuring this reaction as a key step. 相似文献
994.
995.
Jiahui Xian Suisheng Li Hui Su Peisen Liao Shihan Wang Yawei Zhang Wenqian Yang Jun Yang Yamei Sun Yaling Jia Qinglin Liu Prof. Qinghua Liu Prof. Guangqin Li 《Angewandte Chemie (International ed. in English)》2023,62(26):e202304007
How to transfer industrial exhaust gases of nitrogen oxides into high-values product is significantly important and challenging. Herein, we demonstrate an innovative method for artificial synthesis of essential α-amino acids from nitric oxide (NO) by reacting with α-keto acids through electrocatalytic process with atomically dispersed Fe supported on N-doped carbon matrix (AD-Fe/NC) as the catalyst. A yield of valine with 32.1 μmol mgcat−1 is delivered at −0.6 V vs. reversible hydrogen electrode, corresponding a selectivity of 11.3 %. In situ X-ray absorption fine structure and synchrotron radiation infrared spectroscopy analyses show that NO as nitrogen source converted to hydroxylamine that promptly nucleophilic attacked on the electrophilic carbon center of α-keto acid to form oxime and subsequent reductive hydrogenation occurred on the way to amino acid. Over 6 kinds of α-amino acids have been successfully synthesized and gaseous nitrogen source can be also replaced by liquid nitrogen source (NO3−). Our findings not only provide a creative method for converting nitrogen oxides into high-valued products, which is of epoch-making significance towards artificial synthesis of amino acids, but also benefit in deploying near-zero-emission technologies for global environmental and economic development. 相似文献
996.
Hui Luo Dr. Kejun Bu Dr. Yanfeng Yin Dong Wang Cuimi Shi Songhao Guo Tonghuan Fu Jiayuan Liang Bingyan Liu Dr. Dongzhou Zhang Prof. Liang-Jin Xu Prof. Qingyang Hu Prof. Yang Ding Prof. Shengye Jin Prof. Wenge Yang Prof. Biwu Ma Prof. Xujie Lü 《Angewandte Chemie (International ed. in English)》2023,62(37):e202304494
Low-dimensional (low-D) organic metal halide hybrids (OMHHs) have emerged as fascinating candidates for optoelectronics due to their integrated properties from both organic and inorganic components. However, for most of low-D OMHHs, especially the zero-D (0D) compounds, the inferior electronic coupling between organic ligands and inorganic metal halides prevents efficient charge transfer at the hybrid interfaces and thus limits their further tunability of optical and electronic properties. Here, using pressure to regulate the interfacial interactions, efficient charge transfer from organic ligands to metal halides is achieved, which leads to a near-unity photoluminescence quantum yield (PLQY) at around 6.0 GPa in a 0D OMHH, [(C6H5)4P]2SbCl5. In situ experimental characterizations and theoretical simulations reveal that the pressure-induced electronic coupling between the lone-pair electrons of Sb3+ and the π electrons of benzene ring (lp-π interaction) serves as an unexpected “bridge” for the charge transfer. Our work opens a versatile strategy for the new materials design by manipulating the lp-π interactions in organic–inorganic hybrid systems. 相似文献
997.
Minghui Liu Prof. Guigang Zhang Xiaocong Liang Dr. Zhiming Pan Dr. Dandan Zheng Prof. Sibo Wang Prof. Zhiyang Yu Yidong Hou Prof. Xinchen Wang 《Angewandte Chemie (International ed. in English)》2023,62(37):e202304694
In situ photo-deposition of both Pt and CoOx cocatalysts on the facets of poly (triazine imide) (PTI) crystals has been developed for photocatalytic overall water splitting. However, the undesired backward reaction (i.e., water formation) on the noble Pt surface is a spontaneously down-hill process, which restricts their efficiency to run the overall water splitting reaction. Herein, we demonstrate that the efficiency for photocatalytic overall water splitting could be largely promoted by the decoration of Rh/Cr2O3 and CoOx as H2 and O2 evolution cocatalysts, respectively. Results reveal that the dual cocatalysts greatly extract charges from bulk to surface, while the Rh/Cr2O3 cocatalyst dramatically restrains the backward reaction, achieving an apparent quantum efficiency (AQE) of 20.2 % for the photocatalytic overall water splitting reaction. 相似文献
998.
Liangshen Duan Qin Nie Yongxin Hu Liming Wang Kaiyan Guo Zhuoyi Zhou Xu Song Yuanhong Tu Hui Liu Thomas Hansen Jian-song Sun Qingju Zhang 《Angewandte Chemie (International ed. in English)》2023,62(33):e202306971
Herein, we described the first synthesis of the pentasaccharide and decasaccharide of the A. baumannii ATCC 17961 O-antigen for developing a synthetic carbohydrate-based vaccine against A. baumannii infection. The efficient synthesis of the rare sugar 2,3-diacetamido-glucuronate was achieved using our recently introduced organocatalytic glycosylation method. We found, for the first time, that long-range levulinoyl group participation via a hydrogen bond can result in a significantly improved β-selectivity in glycosylations. This solves the stereoselectivity problem of highly branched galactose acceptors. The proposed mechanism was supported by control experiments and DFT computations. Benefiting from the long-range levulinoyl group participation strategy, the pentasaccharide donor and acceptor were obtained via an efficient [2+1+2] one-pot glycosylation method and were used for the target decasaccharide synthesis. 相似文献
999.
Xiaoyang Cheng Xiaotian Jiang Shuhu Yin Lifei Ji Yani Yan Guang Li Rui Huang Prof. Chongtai Wang Prof. Honggang Liao Prof. Yanxia Jiang Prof. Shigang Sun 《Angewandte Chemie (International ed. in English)》2023,62(34):e202306166
To achieve the Fe−N−C materials with both high activity and durability in proton exchange membrane fuel cells, the attack of free radicals on Fe−N4 sites must be overcome. Herein, we report a strategy to effectively eliminate radicals at the source to mitigate the degradation by anchoring CeO2 nanoparticles as radicals scavengers adjacent (Scaad-CeO2) to the Fe−N4 sites. Radicals such as ⋅OH and HO2⋅ that form at Fe−N4 sites can be instantaneously eliminated by adjacent CeO2, which shortens the survival time of radicals and the regional space of their damage. As a result, the CeO2 scavengers in Fe−NC/Scaad-CeO2 achieved ∼80 % elimination of the radicals generated at the Fe−N4 sites. A fuel cell prepared with the Fe−NC/Scaad-CeO2 showed a smaller peak power density decay after 30,000 cycles determined with US DOE PGM-relevant AST, increasing the decay of Fe−NCPhen from 69 % to 28 % decay. 相似文献
1000.
Shuyan Gong Mingze Sun Yiyang Lee Nigel Becknell Jiangwei Zhang Zhongqi Wang Liang Zhang Zhiqiang Niu 《Angewandte Chemie (International ed. in English)》2023,62(4):e202214516
Single crystal surfaces with highly coordinated sites very often hold high specific activities toward oxygen reduction reaction (ORR) and others. Transposing their high specific activity to practical high-surface-area electrocatalysts remains challenging. Here, ultrathin Pt(100) alloy surface is constructed via epitaxial growth. The surface shows 3.1–6.9 % compressive strain and bulk-like characteristics as demonstrated by site-probe reactions and different spectroscopies. Its ORR activity exceeds that of bulk Pt3Ni(100) and Pt(111) and presents a 19-fold increase in specific activity and a 13-fold increase in mass activity relative to commercial Pt/C. Moreover, the electrochemically active surface area (ECSA) is increased by 4-fold compared to traditional thin films (e.g. NSTF), which makes the catalyst more tolerant to voltage loss at high current densities under fuel cell operation. This work broadens the family of extended surface catalysts and highlights the knowledge-driven approach in the development of advanced electrocatalysts. 相似文献