Xing‐Ben Wang  Zhan‐Jiang Zheng  Jia‐Le Xie  Xing‐Wei Gu  Qiu‐Chao Mu  Guan‐Wu Yin  Fei Ye  Zheng Xu  Li‐Wen Xu 《Angewandte Chemie (International ed. in English)》2020,59(2):790-797

A novel and unusual palladium‐catalyzed [4+2] annulation of cyclopropenes with benzosilacyclobutanes is reported. This reaction occurred through chemoselective Si?C(sp²) bond activation in synergy with ring expansion/insertion of cyclopropenes to form new C(sp²)?C(sp³) and Si?C(sp³) bonds. An array of previously elusive bicyclic skeleton with high strain, silabicyclo[4.1.0]heptanes, were formed in good yields with excellent diastereoselectivity under mild conditions. An asymmetric version of the reaction with a chiral phosphoramidite ligand furnished a variety of chiral bicyclic silaheterocycle derivatives with good enantioselectivity (up to 95.5:4.5 er). Owing to the mild reaction conditions, the good stereoselectivity profile, and the ready availability of the functionalized precursors, this process constitutes a useful and straightforward strategy for the synthesis of densely functionalized silacycles.  相似文献   

    

Hongfeng Li  Peng Wu  Yawen Xiao  Meng Shao  Yu Shen  Yun Fan  Huanhuan Chen  Ruijie Xie  Wenlei Zhang  Sheng Li  Jiansheng Wu  Yu Fu  Bing Zheng  Weina Zhang  Fengwei Huo 《Angewandte Chemie (International ed. in English)》2020,59(12):4763-4769

Metal–organic frameworks (MOFs) are promising materials with fascinating properties. Their widespread applications are sometimes hindered by the intrinsic instability of frameworks. However, this instability of MOFs can also be exploited for useful purposes. Herein, we report the use of MOFs as metal ion precursors for constructing functional nanocomposites by utilizing the instability of MOFs. The heterogeneous growth process of nanostructures on substrates involves the release of metal ions, nucleation on substrates, and formation of a covering structure. Specifically, the synthesized CoS with carbon nanotubes as substrates display enhanced performance in a lithium‐ion battery. Such strategy not only presents a new way for exploiting the instability of MOFs but also supplies a prospect for designing versatile functional nanocomposites.  相似文献   

    

Xingchen Jiao  Kai Zheng  Qingxia Chen  Xiaodong Li  Yamin Li  Weiwei Shao  Jiaqi Xu  Junfa Zhu  Yang Pan  Yongfu Sun  Yi Xie 《Angewandte Chemie (International ed. in English)》2020,59(36):15497-15501

Reported here is the first highly selective conversion of various waste plastics into C₂ fuels under simulated natural environment conditions by a sequential photoinduced C?C cleavage and coupling pathway, where single‐use bags, disposable food containers, food wrap films, and their main components of polyethylene, polypropylene, and polyvinyl chloride can be photocatalytically transformed into CH₃COOH without using sacrificial agents. As an example, polyethylene is photodegraded 100 % into CO₂ within 40 h by single‐unit‐cell thick Nb₂O₅ layers, while the produced CO₂ is further photoreduced to CH₃COOH. Various methods and experiments disclose that O₂ and ^.OH radicals trigger the oxidative C?C cleavage of polyethylene to form CO₂, while other investigations show that the yielded CH₃COOH stems from CO₂ photoreduction by C?C coupling of ^.COOH intermediates. This two‐step plastic‐to‐fuel conversion may help to simultaneously address the white pollution crisis and harvest highly valuable multicarbon fuels in natural environments.  相似文献   

    

Jing Zhang  Meng Liu  Chuanhua Wu  Gaoyuan Zhao  Peiqi Chen  Lin Zhou  Xingang Xie  Ran Fang  Huilin Li  Xuegong She 《Angewandte Chemie (International ed. in English)》2020,59(10):3966-3970

The first total synthesis of the Euphorbia diterpenoid pepluanol B in both racemic and enantioenriched form involves 20 steps from a known bicyclic diol. This synthesis features an unprecedented bromo‐epoxidation to control the eight‐membered‐ring conformation. In addition, salient reactions for the construction of the tetracyclic backbone include a sterically challenging aldol reaction to establish the quaternary center, a ring closing metathesis (RCM) to forge the eight‐membered ring, and a diastereoselective cyclopropanation to assemble the embedded cyclopropane motif.  相似文献   

    

Yiren Zhong  Yujun Xie  Sooyeon Hwang  Qian Wang  Judy J. Cha  Dong Su  Hailiang Wang 《Angewandte Chemie (International ed. in English)》2020,59(33):14003-14008

The energetic chemical reaction between Zn(NO₃)₂ and Li is used to create a solid‐state interface between Li metal and Li_6.4La₃Zr_1.4Ta_0.6O₁₂ (LLZTO) electrolyte. This interlayer, composed of Zn, ZnLi_x alloy, Li₃N, Li₂O, and other species, possesses strong affinities with both Li metal and LLZTO and affords highly efficient conductive pathways for Li⁺ transport through the interface. The unique structure and properties of the interlayer lead to Li metal anodes with longer cycle life, higher efficiency, and better safety compared to the current best Li metal electrodes operating in liquid electrolytes while retaining comparable capacity, rate, and overpotential. All‐solid‐state Li||Li cells can operate at very demanding current–capacity conditions of 4 mA cm^?2–8 mAh cm^?2. Thousands of hours of continuous cycling are achieved at Coulombic efficiency >99.5 % without dendrite formation or side reactions with the electrolyte.  相似文献   

    

Chen‐Xi Ye  Shuming Chen  Feng Han  Xiulan Xie  Sergei Ivlev  K. N. Houk  Eric Meggers 《Angewandte Chemie (International ed. in English)》2020,59(32):13552-13556

A transformation of fluxional into configurationally stable axially chiral N‐arylpyrroles was achieved with a highly atroposelective electrophilic aromatic substitution catalyzed by a chiral‐at‐metal rhodium Lewis acid. Specifically, N‐arylpyrroles were alkylated with N‐acryloyl‐1H‐pyrazole electrophiles in up to 93 % yield and with up to >99.5 % ee, and follow‐up conversions reveal the synthetic utility of this new method. DFT calculations elucidate the origins of the observed excellent atroposelectivity.  相似文献   

    

Yixin Xie  Yinzhi Fang  Zhen Huang  Amanda M. Tallon  Christopher W. am Ende  Joseph M. Fox 《Angewandte Chemie (International ed. in English)》2020,59(39):16967-16973

Since tetrazines are important tools to the field of bioorthogonal chemistry, there is a need for new approaches to synthesize unsymmetrical and 3‐monosubstituted tetrazines. Described here is a general, one‐pot method for converting (3‐methyloxetan‐3‐yl)methyl carboxylic esters into 3‐thiomethyltetrazines. These versatile intermediates were applied to the synthesis of unsymmetrical tetrazines through Pd‐catalyzed cross‐coupling and in the first catalytic thioether reduction to access monosubstituted tetrazines. This method enables the development of new tetrazine compounds possessing a favorable combination of kinetics, small size, and hydrophilicity. It was applied to a broad range of aliphatic and aromatic ester precursors and to the synthesis of heterocycles including BODIPY fluorophores and biotin. In addition, a series of tetrazine probes for monoacylglycerol lipase (MAGL) were synthesized and the most reactive one was applied to the labeling of endogenous MAGL in live cells.  相似文献   

    

Fan Xie  Nathan A. Seifert  Wolfgang Jger  Yunjie Xu 《Angewandte Chemie (International ed. in English)》2020,59(36):15703-15710

Chirality recognition in dimers of tetrahydro‐2‐furoic acid (THFA) was studied in a conformer‐specific manner using rotational spectroscopy and theoretical approaches. THFA shows a strong preference for the trans‐ over the cis‐COOH configuration. Two drastically different scenarios are possible for the detectable (THFA)₂: a kinetically preferred dimer bound by feeble interactions between two trans THFAs or a thermodynamically favored dimer with a double hydrogen‐bonded ring structure between two cis subunits. To identify the conformers responsible for the extremely dense rotational spectra observed, it was essential not only to locate several hundred homo/heterochiral (THFA)₂ minima in ab initio calculations but also to evaluate the energetic connectivities among the minima. The study further reveals an interesting chirality dependent structure–energy ordering relationship. A method for enantiomeric excess (ee) determination of THFA is presented using a recently proposed chiral self‐tag approach.  相似文献   

    

Meng Zhao  Hong‐Jie Peng  Bo‐Quan Li  Xiao Chen  Jin Xie  Xinyan Liu  Qiang Zhang  Jia‐Qi Huang 《Angewandte Chemie (International ed. in English)》2020,59(23):9193-9193

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Chengyi Wang  Zihe Zhang  Weiwei Liu  Qinming Zhang  Xin‐Gai Wang  Zhaojun Xie  Zhen Zhou 《Angewandte Chemie (International ed. in English)》2020,59(41)

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