首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
《中国化学》2018,36(7):566-566
The inside cover picture shows Chiral β‐lactams and cyclobutanones are present in numerous natural and pharmaceutical products. A direct preparation of chiral four‐membered rings via metal‐catalyzed asymmetric hydrogenation has not been described yet. In this article, we report an Ir/BiphPHOX‐catalyzed asymmetric hydrogenation of α‐alkylidene β‐lactams and cyclobutanones for the direct preparation of β‐lactams and cyclobutanones bearing an α‐substituted stereocenter. Our tropos phosphine‐oxazoline biphenyl ligand is essential for the preparation of the desired products with high enantioselectivities. More details are discussed in the article by Zhang et al. on page 612–618.

  相似文献   


2.
《中国化学》2018,36(3):173-173
The control of stereoselectivity in radical reactions is of great importance, but remains a formidable challenge. The cover picture shows that the enantiomerically pure compounds can be prepared in radical transformations using chiral transition metal complexes as catalysts. Recent advances are summarized in the review by Kong et al. on page 247–256.

  相似文献   


3.
《中国化学》2018,36(5):373-373
The cover picture shows the complexity of the reaction mechanism of zeolites catalyzed methanol‐to‐olefins (MTO) conversion. The MTO process plays a vital role in the production of light olefins from nonpetroleum resources. Despite of the successful industrialization of the MTO process in China, the detailed reaction mechanism is not yet well understood. The theoretical studies on the MTO hydrocarbon pool mechanism by the Group of Xie are summarized in the Chemistry Author Up Close by Xie et al. on page 381–386.

  相似文献   


4.
《中国化学》2017,35(9):1338-1338
The inside cover picture shows secondary and tertiary amines, which are important intermediates in organic synthesis for the preparation of natural products, pharmaceutical and agronomical compounds. The direct reductive amination of aldehydes and ketones represents a powerful tool for the preparation of secondary and tertiary amines. Here, direct and general reductive amination of aldehydes and ketones with amines and nitroaromatics was presented under H2 using recyclable iridium catalysts, and lots of secondary and tertiary amines were produced in high yields. Moreover, the heterogeneous iridium catalysts Ir@NC(600‐2h) can be reused several times without evident deactivation. More details are discussed in the article by Huang et al. on page 1371–1377.

  相似文献   


5.
《中国化学》2017,35(7):1025-1025
The cover picture shows shows the construction of crown etherstoppering [3]rotaxanes based on N ‐hetero crown ether host. Usually, crown ethers play the role of host macrocycles to combine with the guest molecules in the construction of rotaxanes. Based on the fact that crown ethers have large dimension, two [3]rotaxanes containing four crown ether units were designed and synthesized, of which, two N ‐hetero crown ether components were employed as the macrocyclic hosts to assemble the mechanically interlocked framework by using a template‐directed clipping reaction while bis (metaphenylene‐26‐crown‐8) located on two sides of template diammonium acting as the stoppering groups of [3]rotaxanes. More details are discussed in the article by Yin et al. on page 1050–1056.

  相似文献   


6.
《中国化学》2017,35(10):1650-1650
The back cover picture shows a photocatalytic remediation of polycyclic aromatic hydrocarbons (PAHs) from wastewater with graphene oxide (GO) enwrapped silver phosphate as visible light‐driven photocatalysts. PAHs are a class of highly mutagenic and carcinogenic organic pollutants that pose serious threats to human health and the ecosystem. GO/Ag3PO4 was synthesized by a simple precipitation method. The photocatalysts exhibited superior photocatalytic activity and stability. The degradation efficiency of naphthalene, phenanthrene and pyrene could reach 49.7%, 100.0% and 77.9%, respectively within 5 min irradiation. Meanwhile, the efficiencies of 44.6%, 95.2% and 83.8% were achieved for naphthalene, phenanthrene and pyrene degradation even after 5 times of recycling in the GO/Ag3PO4‐PAHs photocatalysis system. More details are discussed in the article by Bao et al. on page 1549–1558.

  相似文献   


7.
《中国化学》2018,36(1):1-1
The cover picture shows a protocol of a palladium‐catalyzed arylation of vinylarenes with diaryliodonium salts with the assistance of visible light. A palladium‐vinylarene complex may be excited via the visible light irradiation, where the kinetic isotope effect (kH/kD) was around 1.1. However under darkness, the reaction proceeded very slowly, and the kinetic isotope was found as 3.6, indicating the C—H bond cleavage step is the rate‐determining step. This protocol avoided high reaction temperature and enabled us to access a series of ortho tetra‐substituted vinylarene atropisomers with high enantiospecificity. More details are discussed in the article by Gu et al. on page 11–14.

  相似文献   


8.
《中国化学》2017,35(8):1335-1335
The inside back cover picture shows the allosteric modulation of human serum albumin (HSA) induced by the Peptide SA06 ligand. Peptide SA06 is a reported peptide ligand comprising 20 amino acids, and is known to non‐covalently bind with HSA to extend the lifetime and improve the pharmacokinetic performance of drug molecules. The structural evidence on the allosteric interaction between peptide ligand and HSA, and the structure‐affinity relations of the binding mechanism have been revealed in this work, which can also shed light on optimization of therapeutic properties in the affinity‐controlled delivery systems. More details are discussed in the article by Wang et al. on page 1270–1277.

  相似文献   


9.
《中国化学》2018,36(10):889-889
The cover picture shows an electricity powered dehydrogenative [3+2] annulation reaction of (hetero)arylamines with tethered di‐, tri, and tetra‐substituted alkenes for the preparation of indoline and azaindoline products. The electrochemical reactions proceed through H2 evolution and thus avoid the use of stoichiometric chemical oxidants. This method, which is applicable to the preparation of highly functionalized (aza)indoline scaffold, enables the total synthesis of (±)‐hinckdentine A in 12 steps. More details are discussed in the article by Xu et al. on page 909–915.

  相似文献   


10.
《中国化学》2017,35(8):1336-1336
The back cover picture shows schematic of direct in situ liquid cell TEM observation of electron bean induced growth and self‐assembly of nanoclusters in water with the aid of a triblock copolymer. The growth and self‐assembly of the Pt nanoclusters with the aid of triblock copolymer F127 are directly observed, and a surfactant guided nanocluster formation mechanism is proposed. Dramatic differences are found on the cluster forming behavior and final morphologies between thick and thin liquid regions. The difference in precursor availability and charging effects are attributed to the different growth behavior in different thickness regions. More details are discussed in the article by Chen et al. on page 1278–1283.

  相似文献   


11.
《中国化学》2018,36(9):888-888
The back cover picture shows Genkwadane A was isolated from the flower buds of Daphne genkwa which shows bioactivity against HeLa, HepG2, HT‐1080, MCF‐7, A549, U‐937, K562 and HL60 cell lines. It is the first time that a daphnane diterpenoid bearing a 1,10‐double bond was isolated. In this paper, B. Liu and co‐workers report asymmetric synthesis of the ring A substructure of genkwadane A in 10 steps from D‐tartrate derivative. More details are discussed in the article by Liu et al. on page 831–836.

  相似文献   


12.
《中国化学》2017,35(9):1478-1478
The back cover picture shows the asymmetric synthesis of α ‐substituted mercaptoglycine via nickel(II) complex. The α ‐substituted mercaptoglycine is an important framework of various peptide drugs and nickel(II) complex can be utilized to generate single enantiomer of α ‐substituted amino acid efficiently. This work establishes an efficient method to access α ‐substituted mercaptoglycine with good yield and high stereoselectivity, which can promote the design of new peptide drugs in a broad scope. More details are discussed in the article by Wang et al. on page 1383‐1390.

  相似文献   


13.
《中国化学》2018,36(7):671-671
Inside Back Cover picture shows The carps trying hard to make a successful jump over the Dragon Gate will change into fish‐dragons, which is a legend handed down in China over generations. The back cover picture shows photochemical and electrochemical CO2 transformations with organic compounds through the utilization of solar energy or electric energy, producing a series of valuable products, including carboxylic acids and hetero‐cyclic compounds. The combined utilization of both clean energy and CO2 has attracted increasing attention in sustainable development of renewable energy and green chemistry. Recent advances are summarized by He et al. on page 644–659.

  相似文献   


14.
《中国化学》2018,36(7):672-672
The back cover picture shows a convenient and practicable synthesis of novel 2‐(trifluoromethyl)‐6‐arylimidazo[2,1‐b][1,3,4]‐thiadiazole (bis‐)Mannich base derivatives containing various substitutedpiperazine motif. Based on the C‐Mannich reaction of unusual intermediate – 2‐(trifluoromethyl)‐6‐arylimidazothiadiazole, with (4‐substituted) piperazine and formaldehyde in ethanol and acetic acid, the target compounds have been achieved conveniently with satisfying yields. Meanwhile, the cover picture shows that some of the target compounds possess favourable pesticidal activities (e.g. fungicidal and insecticidal). This research will provide important information for relevant synthetic studies of imidazole‐fused‐heterocycle derivatives and their applications in agrochemical area. More details are discussed in the article by Wang et al. on page 635–638.

  相似文献   


15.
《中国化学》2017,35(10):1480-1480
The inside cover picture shows the excellent catalytic performance of mesoporous Nb and Nb‐W oxides catalysts for the conversion of glucose to 5‐hydroxymethylfurfural. The catalytic activity and selectivity for all Nb‐W oxides vary according to the ratio of Brønsted to Lewis acid sites. The highest HMF selectivity of 52% was achieved over Nb7W3 oxide catalyst. More details are discussed in the article by He et al. on page 1529–1539.

  相似文献   


16.
《中国化学》2018,36(2):172-172
The back cover picture shows an efficient dual enantioselective synthesis of 1‐substituted 1,2,3,4‐tetrahydroisoquinoline, which was realized through iridium‐catalyzed hydrogenation of 1‐substituted 3,4‐dihydroisoquinolines. Only tuning the amount of N‐bromosuccinimide, this reaction promoted by (R)‐BINAP is able to furnish both enantiomers of products up to 89% ee (S) and 98% ee (R), respectively. Dual activation role of N‐bromosuccinimide is proposed to be responsible for the reversal of enantioselectivity under two hydrogenation conditions. More details are discussed in the article by Zhou et al. on page 139–142.

  相似文献   


17.
《中国化学》2018,36(8):674-674
The inside cover picture shows Metal‐organic layer (MOL), the two‐dimensional analog of metal‐organic framework (MOF), is a new member of two‐dimensional materials. This tutorial review summarizes current synthetic approaches for MOL preparation. More details are discussed in the article by Wang et al. on page 754–764.

  相似文献   


18.
《中国化学》2018,36(2):85-85
The cover picture shows a series of Cp*Rh‐based molecular Borromean rings (BRs), which consist of three chemically independent rings that are locked in such a way that no two of the three rings are linked with each other. Interestingly, the structure of BRs is very similar to Kong Ming Lock (孔明锁), a kind of Chinese traditional six‐piece burr puzzle. In this work, some of as‐synthesized BRs display high stability in solution. The reason is related to the length ratio of the long‐arm linker and short‐arm linker, where smaller aspect ratios of the metallarectangles promote improved stability of the BRs in solution. Increasing the width of the metallaligand or pyridyl ligand hinders the formation of BRs and leads to unoccupied monomeric rectangles, which were further used as catalysts. More details are discussed in the article by Jin et al. on page 106–111.

  相似文献   


19.
《中国化学》2018,36(2):171-171
The inside back cover picture shows the construction of neutral supramolecular polymeric films containing well‐defined metallacycles as the main scaffolds through combination of coordination‐driven self‐assembly with post‐electropolymerization. A new 120° triphenylamine substituted dicarboxylate donor ligand and the complementary 120° triphenylamine functionalized di‐Pt(II) acceptor were employed to build neutral multi‐triphenylamine functionalized 2‐D metallacycles with the well‐defined shape and size via the formation of oxygen‐to‐platinum coordination bonds. Subsequent post‐electropolymerization of the obtained neutral multi‐triphenylamine containing metallacycles allowed for fabrication of a new type of neutral polymeric film with well‐controlled cavity sizes and thickness, which may have potential applications in neutral molecule detection, separation, and capture. More details are discussed in the article by Yang et al. on page 134–138.

  相似文献   


20.
《中国化学》2018,36(4):372-372
A highly enantioselective one‐pot Strecker reaction of α‐fluoroalkyl α‐aryl ketones, anilines, and TMSCN is disclosed, which simultane‐ously reuses water byproduct and catalyst from the ketimine formation step as a promoter and an additive to improve the reactivity and enantioselectivity of the subsequent Strecker reaction, respectively. The picture shows that the chiral bifunctional tertiary amine mediated asymmetric Strecker reaction is irrigated by the water generated in the p‐TsOH catalyzed ketimine formation, and fertilized by the remaining acid catalyst. More details are discussed in the article by Zhou et al. on page 321–328.

  相似文献   


设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号