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651.
Takahiko Akiyama Prof. Dr. Takuya Katoh Keiji Mori Dr. 《Angewandte Chemie (International ed. in English)》2009,48(23):4226-4228
Let′s resolve our differences : Implementation of an enantioselective Michael addition followed by an intramolecular aldol reaction catalyzed by two phosphoric acids has enabled the synthesis of cyclohexenone derivatives with excellent enantioselectivities. Prominent kinetic resolution was observed in the latter reaction. Ar=aromatic group, X=H, halogen, Y=H, Me, halogen.
652.
Norbert Jux Priv.‐Doz. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(24):4284-4286
More π, please! A free‐base, benzannelated triphyrin with a [2.1.1] bridging pattern ( 1 ) and an azulene‐derived tetracationic all‐carbon porphyrinoid ( 2 ) are discussed. Compound 1 can be used to form metal triphyrin complexes, and 2 shows potential in molecular electronics and as a receptor for weakly binding anions.
653.
654.
Yuan He Jiang Lou Prof. Dr. Zhengkun Yu Prof. Dr. Yong-Gui Zhou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(22):4941-4946
Concise construction of furan and thiophene units has played an important role in the synthesis of potentially bioactive compounds and functional materials. Herein, an efficient Lewis acid ZnCl2 catalyzed [4+1] annulation of alkylthio-substituted enaminones is reported, that is, α-oxo ketene N,S-acetals with sulfur ylides to afford 2-acyl-3-aminofuran derivatives. In a similar fashion, [4+1] annulation of the corresponding enaminothiones, that is, α-thioxo ketene N,S-acetals, with sulfur ylides efficiently proceeded to give multisubstituted 3-aminothiophenes. This method features wide substrate scopes as well as broad functional group tolerance, offering a concise route to highly functionalized furans and thiophenes. 相似文献
655.
Yuka Sakurai Dr. Yohei Ogiwara Prof. Dr. Norio Sakai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(57):12972-12977
A palladium-catalyzed annulation of acyl fluorides with norbornene is described. This study reports the first example of an annulation of acyl fluorides in the presence of a transition-metal catalyst. Polycyclic ketones are obtained from the cleavage of the C−F and C−H bonds of the acyl fluoride and the rearrangement of the carbonyl moiety by decarbonylation and CO reinsertion. 相似文献
656.
Dr. Alberto Insuasty Dr. Subashani Maniam Prof. Steven J. Langford 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(29):7058-7073
This review focuses on describing all known synthetic strategies leading to core-annulation of naphthalene diimides (NDIs). Strategies presented involve the formation of four-, five- and six-membered ring annulations bearing different heteroatomic and carbocyclic derivatives, including annulenes. The core-annulation method opens the possibility for obtaining designer molecules with tuneable electronic characteristics such as a reduced energy band gap, and enhanced intermolecular overlap of π-systems that improve electronic coupling between molecules—which is highly desirable for charge transport properties summarised in the final pages for applications in electronic devices such as organic field-effect transistors (OFETs) and organic photovoltaic (OPV) cells. Molecular recognition in pH and fluoride sensing, or as a DNA probe, are some of additional applications of core-annulated NDIs presented here. Additionally, recent advances in core modification of NDIs are presented, opening an entire new chemical avenue to be explored. Finally, the outlook on the future prospect of annulated NDIs in various applications is summarised. 相似文献
657.
Dr. Elżbieta Gońka Long Yang Ralf Steinbock Dr. Fabio Pesciaioli Dr. Rositha Kuniyil Prof. Dr. Lutz Ackermann 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(71):16246-16250
The widespread applications of substituted diketopyrrolopyrroles (DPPs) call for the development of efficient methods for their modular assembly. Herein, we present a π-expansion strategy for polyaromatic hydrocarbons (PAHs) by C−H activation in a sustainable fashion. Thus, twofold C−H/N-H activations were accomplished by versatile ruthenium(II)carboxylate catalysis, providing step-economical access to diversely decorated fluorogenic DPPs that was merged with late-stage palladium-catalyzed C−H arylation on the thus-assembled DPP motif. 相似文献
658.
We report a Ni‐catalyzed cascade annulation reaction that proceeds through two sequential carbometallation steps followed by C?CN reductive elimination. This reaction transforms two simple starting materials into complex, carbocyclic nitriles. 相似文献
659.
《Tetrahedron letters》2019,60(43):151204
Unusual stereo- and regioselective methods for epoxy-bridge cleavage in perhydro-3a,6-epoxyisoindolones, under the action of the BF3·Et2O/Ac2O system, were discovered. The reaction pathway strongly depends on the characteristics of the isoindolone ring substituents and allows the synthesis of a wide diversity of isoindole-containing heterocycles. The obtained isoindolinones belong to a new class of anti-viral agents possessing a high activity against influenza virus A/Puerto Rico/8/34 (H1N1) in in vitro experiments. 相似文献
660.
A novel rhodium-catalyzed oxidative [5 + 1] annulation of 2-vinylanilines with α-diazocarbonyl compounds for the construction of quinoline-2-carboxylate derivatives has been developed. A series of functional groups such as methyl, methoxy, fluoro, chloro, bromo, cyano, and even thienyl substituents were tolerated well. This methodology has the potential for use in the pharmaceutical industry. 相似文献