全文获取类型
收费全文 | 66篇 |
免费 | 3篇 |
专业分类
化学 | 64篇 |
物理学 | 5篇 |
出版年
2022年 | 1篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 2篇 |
2013年 | 5篇 |
2012年 | 1篇 |
2011年 | 5篇 |
2009年 | 1篇 |
2008年 | 3篇 |
2007年 | 4篇 |
2006年 | 3篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有69条查询结果,搜索用时 21 毫秒
1.
P. Ila 《Journal of Radioanalytical and Nuclear Chemistry》1991,148(2):415-422
Total oxygen, in fourteen rock standards and three ores, was determined with an experimental set up employing cyclic activation analysis using a 14 MeV neutron generator gamma-spectroscopy and NaI(T1) detectors. 相似文献
2.
Ila Sircar 《Journal of heterocyclic chemistry》1985,22(4):1045-1048
The synthesis of novel 6-[4-(1H-imidazol-1-yl)phenyl]-1,2,4-triazolo[4,3-b]pyridazines 8a-f and related compounds is described. Although the intermediate hydrazine derivatives 7 and 9 possess good positive inotropic activity, the fused bicyclic pyridazines 8a-f are significantly less potent than the 3(2H)-pyridazinone 5. Compounds 8a-f are potent but nonselective inhibitors of cardiac phosphodiesterase. 相似文献
3.
Domino carbocationic rearrangements of α-[bis(methylthio)methylene]alkyl-2-(heteroaryl)cyclopropyl ketones (X=O, S, NMe) bearing five-membered heteroaryl group have been investigated. Although the cyclopropyl ketones (R1=H) gave similar products like their aryl counterparts under these conditions, the corresponding α-methylcyclopropyl ketones (R1=Me) yielded a variety of unexpected products depending on the nature of heteroaryl group in the substrate cyclopropyl ketones and the type of acid catalyst used. A probable mechanism for the formation of various products in these transformations has been proposed. 相似文献
4.
Peruncheralathan S Khan TA Ila H Junjappa H 《The Journal of organic chemistry》2005,70(24):10030-10035
[reaction: see text] Highly efficient and regioselective synthesis of 1-aryl-3,4-substituted/annulated-5-(methylthio)pyrazoles and 1-aryl-3-(methylthio)-4,5-substituted/annulated pyrazoles has been reported via cyclocondensation of arylhydrazines with either alpha-oxoketene dithioacetals or beta-oxodithioesters. 相似文献
5.
Mahata PK Venkatesh C Syam Kumar UK Ila H Junjappa H 《The Journal of organic chemistry》2003,68(10):3966-3975
A simple, highly efficient, and regioselective synthesis of functionalized quinolines through Vilsmeier cyclization of a variety of alpha-oxoketene-N,S-anilinoacetals has been reported. The cyclization is found to be facile with N,S-acetals bearing strongly activating groups on aniline, whereas yields of quinolines are moderate in other cases. The reaction could also be extended for the synthesis of substituted tricyclic benzo[h]quinoline, pyrido[2,3-h]quinoline, 4,7-diphenylphenanthroline, and tetracyclic quino[8,7-h]quinoline by performing a Vilsmeier reaction on N,S-acetals derived from 1-naphthylamine, m-phenylenediamine, o-phenylenediamine, and 1,5-diaminonaphthalene, respectively. A few of the newly synthesized quinolines are subjected to further transformation to afford 2-unsubstituted (Raney-Ni/Ethanol), quinoline-5,8-quinone (NBS/H(2)SO(4)), or 2-alkyl/aryl aminoquinolines through sequential m-CPBA oxidation to the corresponding (2-methylsulfonyl)quinoline followed by replacement with appropriate amines. Similarly, cycloannulation of a few 2-methylthio-3-benzoylquinolines with hydrazine hydrate under microwave irradiation afforded the corresponding substituted and fused pyrazolo[3,4-b]quinolines in excellent yields, whereas TBTH/AIBN-mediated cyclization of the corresponding 3-(2-bromobenzoyl)-2-methylthioquinolines yielded the corresponding benzothiopyrano-fused quinolines through radical translocation. 相似文献
6.
Hydrogen peroxide activated by boric acid in the presence of sulfuric acid has been shown to be an efficient oxidizing system for direct conversion of aromatic aldehydes and ketones to phenols. 相似文献
7.
The syntheses of methyl 4‐(4‐nitrophenyl)‐3‐oxomorpholine‐2‐carboxylate ( 3a ) and ethyl 4‐(4‐nitrophenyl)‐2‐oxomorpholine‐3‐carboxylate ( 5b ), important building blocks for the synthesis of factor Xa inhibitor rivaroxaban analogs with potential dual antithrombotic activity, via Rh2(OAc)4‐catalyzed O? H and N? H carbene insertion reactions are described. 相似文献
8.
The dialkylthioacetals, cyclic ethanediylthioacetals and 1,3-dithianes are shown to undergo facile dethioacetalization on heating in dimethylsulphoxide under neutral conditions to afford the corresponding carbonyl compounds in good yields. 相似文献
9.
J. N. Vishwakarma M. Mofizuddin H. Ila H. Junjappa 《Journal of heterocyclic chemistry》1988,25(5):1387-1390
Cyclocondensation of 3(5)-alkylamino- and 3(5-arylaminopyrazoles 1a-c and 1d-e with formaldehyde and primary amines affords novel tetrahydropyrazolo[3,4-d]pyrimidines 2 and tetrahydropyrazolo[1,5-a]triazine derivatives 3 respectivley in good yields. 相似文献
10.