全文获取类型
收费全文 | 127篇 |
免费 | 1篇 |
专业分类
化学 | 83篇 |
晶体学 | 2篇 |
力学 | 2篇 |
数学 | 26篇 |
物理学 | 15篇 |
出版年
2023年 | 3篇 |
2022年 | 6篇 |
2021年 | 7篇 |
2020年 | 2篇 |
2019年 | 5篇 |
2018年 | 4篇 |
2017年 | 7篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 7篇 |
2013年 | 16篇 |
2012年 | 8篇 |
2011年 | 14篇 |
2010年 | 7篇 |
2009年 | 2篇 |
2008年 | 4篇 |
2007年 | 3篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2004年 | 2篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1977年 | 2篇 |
1976年 | 3篇 |
排序方式: 共有128条查询结果,搜索用时 31 毫秒
51.
A convenient synthetic protocol for the synthesis of imidazo[1,2-a]pyridine has been developed by employing one-pot three-component Ugi reaction by employing aromatic amidine, aromatic aldehyde, and isocyanide using 5 mol % of bromodimethylsulfonium bromide (BDMS) at room temperature. In addition, they also exhibit interesting fluorescence properties, which may be useful for fluorescent probe. Mild reaction conditions, non-aqueous work-up procedure, good yields, short reaction time, and no need of chromatographic separation are some of the salient features of the present protocol. 相似文献
52.
Basha MT Chartres JD Pantarat N Ali MA Mirza AH Kalinowski DS Richardson DR Bernhardt PV 《Dalton transactions (Cambridge, England : 2003)》2012,41(21):6536-6548
The iron coordination and biological chemistry of a series of heterocyclic dithiocarbazate Schiff base ligands is reported with regard to their activity as Fe chelators for the treatment of Fe overload and also cancer. The ligands are analogous to tridentate heterocyclic hydrazone and thiosemicarbazone chelators we have studied previously which bear NNO and NNS donor sets. The dithiocarbazate Schiff base ligands in this work also are NNS chelators and form stable low spin ferric and ferrous complexes and both have been isolated. In addition an unusual hydroxylated ligand derivative has been identified via an Fe-induced oxidation reaction. X-ray crystallographic and spectroscopic characterisation of these complexes has been carried out and also the electrochemical properties have been investigated. All Fe complexes exhibit totally reversible Fe(III/II) couples in mixed aqueous solvents at potentials higher than found in analogous thiosemicarbazone Fe complexes. The ability of the dithiocarbazate Schiff base ligands to mobilise Fe from cells and also to prevent Fe uptake from transferrin was examined and all ligands were effective in chelating intracellular Fe relative to known controls such as the clinically important Fe chelator desferrioxamine. The Schiff base ligands derived from 2-pyridinecarbaldehyde were non-toxic to SK-N-MC neuroepithelioma (cancer) cells but those derived from the ketones 2-acetylpyridine and di-2-pyridyl ketone exhibited significant antiproliferative activity. 相似文献
53.
Shaik Firoj Basha Tangella Nagendra Prasad Veera Babu Gudise Vadiga Shanthi Kumar Naveen Mulakayala 《合成通讯》2013,43(22):3181-3190
AbstractA facile one-pot synthesis of ethyl 5-methyl-4,7-dihydrotetrazolo[1,5-a]pyrimidine, 5-tert-butyl-4,7-dihydrotetrazolo[1,5-a]pyrimidine, 6,6-dimethyl-5,6,7,9-tetrahydrotetrazolo[5,1-b]quinazolin-8(4H)-one and 5,6,7,9-tetrahydrotetrazolo[5,1-b]quinazolin-8(4H)-one derivatives were described via a three-component reaction of aldehyde, 5-aminotetrazole and diketones in PEG-400 under microwave irradiation at 110?°C for 30?min. A wide range of diketones such as ethylacetoacetate, tert-butyl acetoacetate, 5,5-dimethylcyclohexane-1,3-dione and 1,3-cyclohexanedione were utilized to carry out the synthesis of different dihydrotetrazolo[1,5-a]pyrimidines and tetrahydrotetrazolo[1,5-a]quinazolinones. This method has the advantage of green protocol, operational simplicity, high yields, recyclability of the solvent and involves isolation of the final product without column purification. The scope of this reaction tolerates with aromatic, heteroaromatic and alicyclic aldehydes. 相似文献
54.
A series of novel menthone oxime ethers were synthesized in three steps starting from (–)-menthol. Analysis of the 13C NMR chemical shift differences between α carbons of oxime derivatives (O-alkyl oximes) provides a convenient and reliable means of assigning oxime stereochemistry. It has been found that carbons syn to the oxime are shifted more upfield than carbons anti to the oxime moiety. Significant E products were obtained. 相似文献
55.
V. Siddaiah G. Mahaboob Basha G. Padma Rao U. Viplava Prasad R. Suryachendra Rao 《合成通讯》2013,43(5):627-634
Hantzsch 1,4-dihydropyridines and polyhydroquinoline derivatives were synthesized in good yields by PEG-mediated, catalyst–free synthesis under solvent-free conditions. The products were directly recrystallized from hot methanol. The reaction gave excellent yields with low- as well as high-molecular-weight polyethylene glycols. 相似文献
56.
57.
58.
Zang Q Javed S Ullah F Zhou A Knudtson CA Bi D Basha FZ Organ MG Hanson PR 《Synthesis》2011,2011(17):2743-2750
The development of a 'click, click, cy-click' process utilizing a double aza-Michael reaction to generate functionalized 1,2,5-thiadiazepane 1,1-dioxides is reported. Optimization in flow, followed by scale out of the inter-/intramolecular double aza-Michael addition has also been realized using a microwave-assisted, continuous flow organic synthesis platform (MACOS). In addition, a facile one-pot, sequential strategy employing in situ Huisgen cycloaddition post-double aza-Michael has been accomplished, and is applicable to library synthesis. 相似文献
59.
60.
Basha S. K. Thaslim Kalla Reddi Mohan Naidu Varalakshmi M. Sudhamani H. Appa Rama Moorthy Chul Hong Sung Raju Chamarthi Naga 《Molecular diversity》2022,26(5):2703-2715
Molecular Diversity - Silica-supported lanthanum (III) chloride (SiO2–LaCl3·7H2O) was prepared and characterized by infrared spectroscopy, X-ray diffraction analysis, scanning electron... 相似文献