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Zhong Ping TAN Lin WANG Jian Bo WANG Department of Chemistry Peking University Beijing 《中国化学快报》2000,(9)
The protection of functional group is unavoidable in multi-step organic synthesis. Alongwith tetrahydropyranyl (THP) ethers, t-butyldimethylsilyl (TBDMS) ethers have beenwidely used for protecting hydroxyl groups. TBDMS ether is more stable to hydrolysisthan trimethylsilyl ether, but is still readily cleaved by a variety of selective conditionsl.The deprotection of TBDMS is usually under mild acidic conditions [AcOH/H,O/THF,3t l: l', or BF, Et,O/CHCI,', etc. '], or with a fluoride… 相似文献
174.
Tomoya Ozaki Prof. Dr. Hideki Yorimitsu Dr. Gregory J. P. Perry 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(62):15387-15391
Despite common occurrence in molecules of value, methods for transforming sulfonamides are distinctly lacking. Here we introduce easy-to-access sulfonyl pyrroles as synthetic linchpins for sulfonamide functionalization. The versatility of the sulfonyl pyrrole unit is shown by generating a variety of products through chemical, electrochemical and photochemical pathways. Preliminary results on the direct functionalization of primary sulfonamides are also provided, which may lead to new modes of activation. 相似文献
175.
Tetrahydropyranyl (THP) ethers have been efficiently and simply deprotected by using Silica supported sodium hydrogen sulphate (NaHSO4‐SiO2) in methanol at room temperature to regenerate the parent alcohols in high yields. 相似文献
176.
Carmela Napolitano Manuela Borriello Francesca Cardullo Daniele Donati Alfredo Paio 《合成通讯》2013,43(14):2031-2035
A rapid and efficient synthesis of 1-benzyl-2-difluoromethyl-piperazine is herein described. The new pathway has the advantage of avoiding orthogonal protection at the two piperazine nitrogen atoms; therefore it is suitable for access to several 1-benzyl 2-substituted piperazines starting from the simple commercially available N,N′-dibenzylethylendiamine. 相似文献
177.
Li Zhan Shuyuan Chang Ting Liu Shanbao Yu Hui Li Minjie Lu Yong Zhu Yu Luo Jiahui Yu Fan Yang Jie Tang 《Tetrahedron letters》2017,58(50):4724-4727
We describe the synthesis and characterization of a type of pH-sensitive pentaerythritol phospholipids, using a trialkoxybenzylidene acetal as the acid-labile moiety. This lipid was prepared by an eight-step synthesis via a latentiation strategy. Liposomes were prepared via the thin film extrusion method. The changes of liposomal sizes were measured by dynamic light scattering. Content release rates of the liposomes as a function of pH were monitored by using a calcein fluorescence dequenching assay. These results indicated that this new liposomal system was capable of releasing its contents under mildly acidic conditions. At last, in vitro cytotoxicity was assayed against three cell lines, suggesting this type of phospholipids was low toxic. 相似文献
178.
Bahram Yadollahi Valiollah Mirkhani Shahram Tangestaninejad Davud Karimian 《应用有机金属化学》2011,25(2):83-86
Herein, we want to report a simple and convenient way for protection‐deprotection of alcohols in the presence of ammonium decatungstocerate(IV) {(NH4)8[CeW10O36]·20H2O} as catalyst under ambient temperature in CH3CN. Using 0.002 mmol of the catalyst, various alcohols and phenols were transformed easily to the corresponding TMS ethers in excellent yields. In the second part, various TMS ethers were successfully converted to the parent hydroxyl compounds in the presence of the ammonium decatungstocerate(IV) catalyst. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
179.
The title compounds can be prepared in good yields in a one-pot procedure from arylglyoxylic acid chlorides, 2-pyridone and O-alkylhydroxylamines. 相似文献
180.
(-)-(4aS,8aR)-5,5-8a-trimethyl-trans-decaline 1 was prepared in a stereoespecific synthesis of 4 steps and 38% yield. The key-step involves an asymmetric Robinson annulation via Michael addition of chiral imine. 相似文献