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排序方式: 共有169条查询结果,搜索用时 15 毫秒
101.
A variety of allylic, benzylic, primary, and secondary saturated alcohols have been converted into the corresponding iodides using NaI supported on KSF clay. Selective conversion of allylic and benzylic alcohols in the presence of primary and secondary saturated alcohols has also been demonstrated. 相似文献
102.
Direct reductive amination of aldehydes and ketones were accomplished efficiently using high-capacity, ionene-based, polymer-supported borohydride reagent in isopropyl alcohol at reflux under neutral conditions. The reagent is easily prepared by mixing aqueous solution of 2,4-ionene bromide with an alkaline solution of sodium borohydride at room temperature. The generality of reaction was established using both aliphatic and aromatic aldehydes, ketones, and amines. 相似文献
103.
A regioselective and highly efficient method for bromination of phenol and aniline derivatives using ethylenebis(N-methylimidazolium) ditribromide (EBMIDTB) as an efficient reagent in dichloromethane at ambient temperature is reported. The reagent can be recovered and reused several times. 相似文献
104.
New β-acetamido ketone derivatives are synthesized through a one-pot, four-component reaction of benzaldehyde, dimedone, acetyl chloride, and acetonitrile in the presence of cellulose sulfuric acid as an efficient reusable catalyst. The procedure offers advantages in terms of good yields, short reaction times, mild reaction conditions, and reusability of the catalyst. 相似文献
105.
Fatemeh JahaniMahmood Tajbakhsh Hamid GolchoubianSamad Khaksar 《Tetrahedron letters》2011,52(12):1260-1264
A simple and efficient method for the chemoselective N-Boc protection of the amine moiety in a variety of compounds is described using di-tert-butyl dicarbonate and guanidine hydrochloride as an organocatalyst in ethanol at 35-40 °C. Selective mono-N-Boc protection of diamines and chemoselective protection of hydroxylamines without formation of any side products is achieved. Amino acids and peptides are N-Boc protected efficiently in excellent yields under convenient reaction conditions. 相似文献
106.
Satoshi Suzuki Shunsuke Sasaki Amir Sharidan Sairi Riki Iwai Ben Zhong Tang Gen‐ichi Konishi 《Angewandte Chemie (International ed. in English)》2020,59(25):9856-9867
Twenty years ago, the concept of aggregation‐induced emission (AIE) was proposed, and this unique luminescent property has attracted scientific interest ever since. However, AIE denominates only the phenomenon, while the details of its underlying guiding principles remain to be elucidated. This minireview discusses the basic principles of AIE based on our previous mechanistic study of the photophysical behavior of 9,10‐bis(N,N‐dialkylamino)anthracene ( BDAA ) and the corresponding mechanistic analysis by quantum chemical calculations. BDAA comprises an anthracene core and small electron donors, which allows the quantum chemical aspects of AIE to be discussed. The key factor for AIE is the control over the non‐radiative decay (deactivation) pathway, which can be visualized by considering the conical intersection (CI) on a potential energy surface. Controlling the conical intersection (CI) on the potential energy surface enables the separate formation of fluorescent (CI:high) and non‐fluorescent (CI:low) molecules [control of conical intersection accessibility ( CCIA )]. The novelty and originality of AIE in the field of photochemistry lies in the creation of functionality by design and in the active control over deactivation pathways. Moreover, we provide a new design strategy for AIE luminogens (AIEgens) and discuss selected examples. 相似文献
107.
Mahmood Tajbakhsh Rahman Hosseinzadeh Farhad Ramzanian‐Lahmali Marzieh Sadatshahabi 《中国化学会会志》2005,52(5):1005-1009
2,6‐Dicarboxypyridinium fluorochromate as a new, rapid, and efficient reagent was prepared and used for the oxidative deprotection of oximes, phenylhydrazones, and semicarbazones to their carbonyl analogues under solvent‐free conditions at room temperature. 相似文献
108.
Noguchi T Tanaka N Nishimata T Goto R Hayakawa M Sugidachi A Ogawa T Asai F Fujimoto K 《Chemical & pharmaceutical bulletin》2007,55(10):1494-1504
A series of cinnamylindoline derivatives were synthesized, and their factor Xa (FXa) inhibitory activities and selectivity over trypsin were evaluated. Among them, some novel derivatives showed potent FXa inhibitory activities and good selectivity over trypsin. Especially, (E)-2-{5-[1-(acetimidoyl)piperidin-4-yloxy]-2-[2-(5-amidino-2-hydroxyphenyl)ethen-1-yl]indolin-1-ylsulfonyl}acetic acid (22f) having 2-hydroxycinnamyl moiety exhibited the most potent FXa inhibitory activity in vitro. Furthermore, 22f also exhibited potent anticoagulant activities in vitro. 相似文献
109.
A heteropolyacid efficiently catalyzed the cyclocondensation reaction of 2‐aminobenzamide and salicylamide with aldehydes and ketones to afford good yields of benzoxazine and quinazoline ring systems in an aqueous medium. The method gives clean reactions, has simple workup procedure, and uses environment friendly conditions. 相似文献
110.
Moslem Mansour Lakouraj Mahmood Tajbakhsh Farhad Ramzanian-Lehmali Keyvan Ghodrati 《Monatshefte für Chemie / Chemical Monthly》2008,139(5):537-541
Oxidative deprotection of trimethylsilyl and tetrahydropyranyl ethers, and deprotection of phenylhydrazones, semicarbazones,
and oximes to their corresponding carbonyl compounds carried out in water at reflux condition using ionene supported peroxodisulfates
is reported. The reagents are recyclable and products are obtained in excellent yield under environmentally benign conditions
without overoxidation to carboxylic acid.
Correspondence: Moslem Mansour Lakouraj, Department of Chemistry, Mazandaran University, Babolsar, Iran. 相似文献