Abstract We report here the facile, room temperature, catalyst free, one pot synthesis of aliphatic bridged diaryloxy compounds, cyclic and crownethers. Anhydrous potassium carbonate (K2CO3) as a mild base along with dimethyl sulfoxide generates the phenoxide ion which facilitates the nucleophilic substitution of bromoalkanes to yield the corresponding crownethers.
An Efficient Synthetic Strategy for Geometrically Pure Symmetrical and Unsymmetrical Hydroxystilbenes via McMurry Coupling
作者:Subrata Chattopadhyay、Narayan V. Mayekar、Sandip K. Nayak
DOI:10.1055/s-2003-41004
日期:——
Intramolecular reductive deoxygenation of ethylene-dioxy tethered symmetrical and unsymmetrical aromatic bis(carbonyl) ethers with the low-valenttitanium (LVT) reagent (TiCl 4 -Zn-THF) yielded chromatographically separable E/Z-isomers of corresponding cyclic stilbenes which were further dealkylated to obtain geometrically pure hydroxystilbenes. The intramolecular McMurry coupling of the tethered bis(carbonyl)
Use of Polyoxetane Resin-Supported Quaternary Onium Salts as a Polymeric Phase-Transfer Catalyst for Preparing Ethers from Hydroxy Compounds and Alkyl Halides
作者:Masatoshi Motoi、Katsuhiko Shimamura、Chikako Shimamura、Satoru Muramoto、Shigeyoshi Kanoh、Hiroshi Suda
DOI:10.1246/bcsj.62.2553
日期:1989.8
bromine of the pendant groups of such polyoxetane resins was quaternized with tributylamine or tributylphosphine in DMF in order to examine the phase-transfer catalyzing ability of the resultant quaternary onium bromides in the etherification reaction between alkyl halides and alcohols or phenols. These reactions gave the desired products in fairly good yields within reaction periods of 1–3 h, indicating
Microwave-Assisted Synthesis of Bis(enaminoketones): Versatile Precursors for Novel Bis(pyrazoles)<i>via</i>Regioselective 1,3-Dipolar Cycloaddition with Nitrileimines
作者:Ahmed H. M. Elwahy、Ahmed F. Darweesh、Mohamed R. Shaaban
DOI:10.1002/jhet.952
日期:2012.9
Synthesis of bis(enaminones) 6a, 6b, 6c and 7a, 7b, 7c was accomplished by the reaction of bis(acetophenones) 3a, 3b, 3c and 4a, 4b, 4c with dimethylformamide–dimethylacetal, under microwave irradiation. 1,3‐Dipolar cycloaddition of bis(enaminones) 6a and 7b, 7c with nitrileimines in refluxing benzene led to the regioselective synthesis of the novelbis(pyrazoles) 11a, 11b, 11c, 11d, 11e, 11f, 11g
双(苯乙酮)3a,3b,3c和4a,4b,4c与二甲基甲酰胺-二甲基乙缩醛在微波辐射下的反应完成了双(烯胺酮)6a,6b,6c和7a,7b,7c的合成。双(烯胺)6a和7b,7c与亚硝基亚胺在回流的苯中的1,3-偶极环加成反应导致新的双(吡唑)11a,11b,11c的区域选择性合成,11d,11e,11f,11g,11h,产率为62-89%。双(吡唑)11b,11c与水合肼缩合,以高收率得到相应的双(吡唑并[3,4- d ]哒嗪)14a,14b。
Bis(enaminones) as Versatile Precursors for Novel Bis([1,2,4]triazolo[1,5‐<i>a</i>]pyrimidines) and Bis(2‐thioxo‐2,3‐dihydropyrido[2,3‐<i>d</i>]pyrimidin‐4(1<i>H</i>)‐ones)
作者:Ibrahim M. Z. Fares、Ahmed E. M. Mekky、Ismail A. Abdelhamid、Ahmed H. M. Elwahy
DOI:10.1002/jhet.3575
日期:2019.7
Novel bis([1,2,4]triazolo[1,5‐a]pyrimidines) and bis(2‐thioxo‐2,3‐dihydropyrido[2,3‐d]pyrimidin‐4(1H)‐ones) were prepared utilizing bis(enaminones) as precursors. The structures of the prepared compounds were elucidated by several spectral tools as well as elemental analyses.
新颖的bis([1,2,4] triazolo [1,5- a ]嘧啶)和bis(2-thioxo-2,3-dihydropyrido [2,3- d ] pyrimidin-4(1 H)-ones)是。以双(烯胺酮)为前体制备。通过几种光谱工具以及元素分析阐明了所制备化合物的结构。