全文获取类型
收费全文 | 143篇 |
免费 | 4篇 |
专业分类
化学 | 102篇 |
晶体学 | 2篇 |
力学 | 4篇 |
数学 | 15篇 |
物理学 | 24篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 8篇 |
2019年 | 9篇 |
2018年 | 9篇 |
2017年 | 6篇 |
2016年 | 5篇 |
2015年 | 3篇 |
2014年 | 9篇 |
2013年 | 16篇 |
2012年 | 13篇 |
2011年 | 9篇 |
2010年 | 7篇 |
2009年 | 4篇 |
2008年 | 7篇 |
2007年 | 3篇 |
2006年 | 9篇 |
2005年 | 3篇 |
2004年 | 1篇 |
2003年 | 3篇 |
2002年 | 3篇 |
1999年 | 1篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1936年 | 1篇 |
排序方式: 共有147条查询结果,搜索用时 15 毫秒
1.
The stereoselective intramolecular cyclizations of bis(cinnamyl)tosylamides and dimethyl bis(cinnamyl)malonates mediated by cerium(IV) ammonium nitrate leading to the synthesis of 3,4-trans-disubstituted pyrrolidines and cyclopentanes are described. 相似文献
2.
P. Kumar K. N. Dhawan K. Kishor K. P. Bhargava R. K. Satsangi 《Journal of heterocyclic chemistry》1982,19(3):677-679
The Condensation of 3,4-disubstituted phenylethylamine and benzaldehyde furnished l-phenyl-6,7-disubstituted-1,2,3,4-tetrahydroisoquinolines l. which on reaction with 1,3-dibromopropane gave l-phenyl-6,7-disubstituted-2-(3-bromoprophyl)-1,2,3,4-tetrahydroisoquinolines 2. The reaction of 2 with different secondary amines resulted in the synthesis of 3. The compounds 3 were screened for their in vitro antituberculer activity against Mycobacterium smegmatis, and some of them have been found to be total inhibitors of M. Smegmatis 相似文献
3.
A new, green, regioselective, one-step, tandem reaction of an aldehyde possessing a non-enolizable carbonyl function with a highly substituted cyclohex-2-enone, under amine catalysis afforded highly substituted phenols or 2-arylidenecyclohexanones, respectively. The yields and regioselectivities were good. Evidence for a pathway involving formation of novel push-pull dienamines is presented along with examples demonstrating the amenability of the process to combinatorial chemistry. 相似文献
4.
A novel and green approach for the two-carbon homologation of aldehydes using amino acid catalysis has been developed and further extended to the generation of pharmaceutically active cyano-esters via four-component reactions in one-pot. 相似文献
5.
Patel Janki J. Modh Rahul P. Asamdi Manjoorahmed Chikhalia Kishor H. 《Molecular diversity》2021,25(4):2271-2287
Molecular Diversity - Practical synthesis and biological activities of quinazolinyl–triazinyl semicarbazides (10a–j) and quinazolinyl–triazinyl thiosemicarbazides (11a–j)... 相似文献
6.
Patel Anuj P. Shaikh Mohammedumar M. Gurjar Kamlesh K. Chikhalia Kishor H. 《Research on Chemical Intermediates》2021,47(5):2049-2061
Research on Chemical Intermediates - Indenoquinolinones have been synthesized from 2-haloquinoline-3-carbaldehyde through Pd-mediated simultaneous C–H (aldehyde) and C–X bond... 相似文献
7.
We have developed a new technology called multi-catalysis for the sequential one-pot synthesis of highly functionalized heterocycles. A practical and novel multi-component aniline-, self- and Br?nsted acid-catalyzed selective process for the sequential one-pot synthesis of highly substituted 2-(2-hydroxy-aryl)-cyclopentane-1,3-diones, 3,9-dihydro-2H-cyclopenta[b]chromen-1-ones and 3,3-dimethyl-2,3,4,9-tetrahydro-xanthen-1-ones is reported. Direct combination of aniline- and self-catalyzed cascade olefination-hydrogenation (O-H) and Br?nsted acid-catalyzed cascade oxy-Michael-dehydration (OM-DH) of 1,3-diones, salicylic aldehydes and organic-hydrides is developed in one-pot to furnish the highly functionalized 3,9-dihydro-2H-cyclopenta[b]chromen-1-ones and 3,3-dimethyl-2,3,4,9-tetrahydro-xanthen-1-ones with high yields. 相似文献
8.
[reaction: see text] Reaction of the Huisgen zwitterion, derived from triphenylphosphine and dialkyl azodicarboxylate, with allenic esters affords highly functionalized pyrazolines and pyrazoles. The crystal structure of pyrazoline derivative 7a showed extensive C-H...O interactions. Pyrazole formation proceeds via a novel nitrogen to carbon migration of the carboalkoxy group. 相似文献
9.
Pamela Alex Jugal Kishor I. G. Sharma 《Journal of Thermal Analysis and Calorimetry》2013,112(1):45-50
The aim of this work is to evaluate the feasibility of preparation of Nb10Hf1Ti alloy by magnesiothermic reduction of its oxides. DTA studies were conducted to identify the reduction temperature for co reduction of the mixed oxides of Nb2O5, HfO2, and TiO2 by magnesium under reducing atmosphere. Based on DTA analysis, experiments were carried out to prepare Nb10Hf1Ti alloy by magnesiothermic reduction of their oxides at 750 °C. The reduced product was analyzed for its phases by X-ray diffraction. The excess Mg was leached out, the alloy mixture was vacuum dried, pelletized, sintered, and electron beam melted to get a consolidated alloy of the required composition. The alloy was characterized using different techniques such as optical microscopy, scanning electron microscopy, and chemical analysis. Microstructural observations revealed the formation of coarse grain structure in the consolidated alloy. The alloy product was also evaluated for its micro hardness. 相似文献
10.
Satish N. Dighe Ravindra V. Bhattad Raghunath R. Kulkarni Kishor S. Jain 《合成通讯》2013,43(23):3522-3527
The synergy of the combined use of DMSO and an ionic liquid viz. (bbim)+Br? has brought about a rapid and efficient esterification of sodium carboxylates with acyl and alkyl halides under ambient conditions in excellent isolated yields (90–95%) in short reaction times (12–40 min). 相似文献