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51.
Jun LIU Qing Hua BIAN Ming An WANG Hong Chao GUO Min WANG 《中国化学快报》2006,17(5):606-608
Optically active TADDOL (α, α, α′, α′-tetraaryl-1, 3-dioxolane-4, 5-dimethanol) and the related ligands have played a significant role in asymmetric reactions1. Although several hundreds of different TADDOLs and TADDOL analogues have already been de 相似文献
52.
Ling Chen Dr. Thi Minh Thi Le Prof. Dr. Jean-Philippe Bouillon Prof. Dr. Thomas Poisson Prof. Dr. Philippe Jubault 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(42):e202201254
The catalytic asymmetric synthesis of highly functionalized cyclopropanes from α-substituted allyl sulfones and silanes is reported. The reaction, using α-aryl diazoacetates or diacceptor diazo reagents, catalyzed by a chiral rhodium complex (Rh2((S)-BTPCP)4), furnished the corresponding cyclopropanes in moderate to high yields (27–97 %), high diastereoselectivities (68 : 32 to 20 : 1 d.r.) and moderate to excellent ee (40–99 %). This methodology offers a privileged access to an underexplored class of enantioenriched cyclopropanes with a high level of functionality, an asset for further post-functionalization and their incorporation into more complex structure. 相似文献
53.
Alexey O. Chagarovskiy Olga A. IvanovaEkaterina M. Budynina Igor V. Trushkov Mikhail Ya. Melnikov 《Tetrahedron letters》2011,52(34):4421-4425
A novel Lewis acid catalyzed [3+2] cyclodimerization of 2-arylcyclopropane-1,1-dicarboxylates is reported. It is the first example of a reaction wherein a donor-acceptor cyclopropane provides two carbons in a newly formed ring. The described cyclodimerization represents a general convenient approach to polyfunctionalized cyclopentanes. 相似文献
54.
The novel procedure for synthesis of cyclopropyl lactams incorporating benzothiazole structure units from cis‐2‐aryl‐1‐benzoyl‐3,3‐dicynocyclopropane and 2‐cyanomethyl‐1,3‐benzothiazole has been achieved. This method is highly stereoselective and environmentally friendly. 相似文献
55.
Jeffrey H. Byers Peter H. Goff Nicholas J. Janson Michael G. Mazzotta John E. Swigor 《合成通讯》2013,43(11):1865-1871
The phenylseleno radical–catalyzed addition of dimethyl 2‐ethynylcyclopropane‐1,1‐dicarboxylate to electron–rich olefins has been achieved. This radical process leads to formation of highly substituted ethynylcyclopentane products through a [3+2] annulation. 相似文献
56.
57.
Rika Okuma Tomoki Kuwahara Takafumi Yoshikane Mizuki Watanabe Patricia Dranchak James Inglese Satoshi Shuto Yuki Goto Hiroaki Suga 《化学:亚洲杂志》2020,15(17):2631-2636
Here we report the construction of an mRNA‐encoded library of thioether‐closed macrocyclic peptides by using an N‐chloroacetyl‐cyclopropane‐containing exotic initiator whose structure is more constrained than the ordinary N‐chloroacetyl‐α‐amino acid initiators. The use of such an initiator has led to a macrocycle library with significantly suppressed population of lariat‐shaped species compared with the conventional libraries. We previously used a conventional library and identified a small lariat thioether‐macrocycle with a tail peptide with a C‐terminal free Cys whose sidechain plays an essential role in potent inhibitory activity against a parasitic model enzyme, phosphoglycerate mutase. On the other hand, the cyclopropane‐containing macrocycle library has yielded a larger thioether‐macrocycle lacking a free Cys residue, which exhibits potent inhibitory activity to the same enzyme with a different mode of action. This result indicates that such a cyclopropane‐containing macrocycle library would allow us to access mechanistically distinct macrocycles. 相似文献
58.
Abstract N-Aryl-trans,trans-α-carboxyl-β-benzoyl-γ-aryl-γ-butyrolactams were synthesized in high yields with high stereoselectivity by the reaction of electron-deficient cyclopropane derivatives, cis-1-benzoyl-2-aryl-6,6-dimethyl-5,7-dioxo-spiro-[2 5]-4,8-octadiones, with aromatic amines. The reaction mechanism was proposed. 相似文献
59.
Min CHEN Rong QIAN Hai‐Yan JIANG Xiang ZHANG Jing ZHOU Wei‐Guo CAO Yin‐Long GUO 《中国化学》2008,26(5):923-928
Electrospray ionization mass spectrometry (ESI‐MS) was utilized to perform monitoring of the intermediates in the reaction of 1,2,3‐trisubstituted electron‐deficient cyclopropane derivatives, cis‐1‐thien‐2′‐oyl‐2‐(p‐subustituted phenyl‐6,6‐dimethyl)‐5,7‐dioxaspiro[2.5]‐4,8‐octadiones, with methanol. Key intermediates, either cationic or protonated forms of neutral species, were intercepted and characterized by ESI‐MS and its tandem version (ESI‐MS/MS). Therefore, the mechanism of the ring‐opening process for electron‐deficient cyclopropane derivatives was fully confirmed by the intermediates monitored. 相似文献
60.
Prof. Dr. Takeshi Hanamoto 《Chemical record (New York, N.Y.)》2023,23(9):e202200270
The fluorinated building block strategy and the direct fluorination strategy are of great importance for the synthesis of new fluorinated molecules. These strategies complement each other and can be combined to develop a new methodology for the construction of a wide variety of fascinating organofluorine compounds. In our opinion, the versatile building blocks used in this method should satisfy the following conditions: 1) readily prepared from commercially available reagents; 2) easy to handle; 3) storage under ordinary conditions without noticeable decomposition; 4) wide applicability. Based on the aforementioned requirements, we focused on the use of vinyl sulfonium salts. This brief review describes the synthesis of five types of fluorinated vinyl sulfonium salts and their reactions. Especially, we featured typical fluorinated groups containing trifluoromethyl (CF3), difluoromethyl (CF2H), monofluoromethyl (CFH2), monofluoro (F) or β-bromotetrafluoroethyl (BrCF2CF2) moieties in combination with vinyl sulfonium salts. 相似文献