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471.
Kelly L. Cosgrove 《Tetrahedron》2010,66(16):3050-5675
A practical entry into δ-ethoxycarbonyl-α,β-unsaturated nitriles is described. α,β-Unsaturated aldehydes were converted to cyanohydrins, by employing either KCN in aqueous acid, or by using TMSCN with catalytic K2CO3, followed by acid hydrolysis of the TMS ether. These cyanohydrins underwent a Claisen rearrangement employing a modified Johnson-Claisen protocol to yield unsaturated nitriles in good yields and with moderate E/Z selectivity. 相似文献
472.
Fang Fang 《Tetrahedron》2010,66(20):3593-6201
A novel class of atropos dibridged biphenyl phosphoramidites bearing a D2-symmetric biphenyl backbone was prepared and applied as chiral ligands in the copper-catalyzed allylic alkylation with Grignard reagent. The alkylation products were obtained in quantitative yields with high regioselectivities up to 94:6 of SN2′/SN2 ratio and enantiomeric excesses up to 91.1% for SN2′ products. The unique D2-symmetric backbone ligands have the advantages of easy preparation and sufficient reusability of their key intermediates from the undesired isomers. 相似文献
473.
B.V. Subba Reddy N. Sivasankar Reddy Ch. Madan J.S. Yadav 《Tetrahedron letters》2010,51(37):4827-8621
A variety of alkenes undergo smooth amidation with nitriles in the presence of HBF4·OEt2 at room temperature under mild conditions to afford the corresponding secondary amides in good to excellent yields. This is a highly efficient method for the preparation of α-aryl ethyl amides especially from vinyl arenes without any side reactions such as olefin polymerization. The use of readily available and easy to handle reagent HBF4·OEt2 makes this method simple, convenient, and practical. 相似文献
474.
Selectfluor-promoted fluorination of piperidinyl olefins 总被引:1,自引:0,他引:1
Meng-Yang Chang Nien-Chia Lee Ming-Fang Lee Yu-Ping Huang Chung-Han Lin 《Tetrahedron letters》2010,51(45):5900-5903
A simple and straightforward synthesis of 1-substituted-4-aryl-5-fluoro-1,2,3,6-tetrahydropyridine (3) or 1-substituted 4-diarylmethanoyl-4-fluoropiperidine (6) by the treatment of piperidinyl exo- or endo-olefin with 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate (Selectfluor) is reported. Two transformations from endo-olefin 1 to allylic fluoride 3 and from exo-olefin 2 to fluorohydrin 6 proceed via allylic fluorination and fluorohydroxylation in moderate yields. It presents two novel reactions promoted by Selectfluor and broadens the scope of application. 相似文献
475.
Madhesan Balakrishnan 《Tetrahedron letters》2010,51(42):5571-5573
A cross-coupling reaction between a homoallylic alcohol and styrene is described to broaden the scope of the titanium alkoxide tether-mediated coupling reactions. Particularly noteworthy is exceptional 1,3-diastereoselectivity by o-vinylanisole in coupling with a Z-homoallylic alcohol. 相似文献
476.
477.
Youtian Fu Ling Zhang Maolin Sun Liming Cao Lei Yang Prof. Dr. Ruihua Cheng Prof. Dr. Yueyue Ma Prof. Dr. Jinxing Ye 《European journal of organic chemistry》2023,26(35):e202300553
Due to the high oxidation potentials of electron-deficient aromatic hydrocarbons, it is difficult to achieve the direct oxidative C(sp2)−H bonds functionalizations of such substrates. Herein, we develop a Ritter-type amination of electron-deficient aromatics by merging electricity and sulfate. This practical and straightforward method provides a series of acetanilides from simple electron-deficient arenes, including mono-, di- and tri-substituted arenes (22 examples, up to 75 %) with moderate to good yields under mild conditions. This method is characterized by cheap and readily available regents, atom and step economy. 相似文献
478.
An-Jing Wang Yu-Die Zhang Wen-Jing Nan Shan Liu Prof. Dr. Wen-Ming Shu Prof. Dr. Yin-Xiang Gong 《European journal of organic chemistry》2023,26(19):e202300154
Here we report the preparation of primary α-ketoamides via a highly efficient molecular iodine-mediated oxidative amidation of aryl methyl ketones with ammonium carbamodithioate. A self-sequenced iodination/nucleophilic substitution/Kornblum oxidation/amidation mechanism was proposed. In this mechanism, α-thiocyanatoacetophenone is the key intermediate. 相似文献
479.
《Mendeleev Communications》2023,33(1):73-76
Novel 2-amino-4-(aminomethyl)thiazole derivatives were designed and synthesized by a facile method including the Hantzsch construction of thiazole core followed by amidation and nucleophilic substitution steps. Bioassay results showed that 4-(tert-butyl)-N-[4-(piperazin-1-ylmethyl)thiazol-2-yl]-benzamide and 4-(tert-butyl)-N-{4-[(4-piperidinopiperidin-1-yl)methyl]thiazol-2-yl}benzamide possessed similar activities compared with 5-fluorouracil. The 4-piperidino-piperidin-1-yl-containing derivative also suppressed proliferation of cultured tumor cells by inducing apoptosis. 相似文献