نتایج جستجو برای: sulfonatocalix4 arene

تعداد نتایج: 2973  

Journal: :Chemical communications 2013
Lingyan Gao Chengyou Han Bo Zheng Shengyi Dong Feihe Huang

It was demonstrated that a novel [3]pseudorotaxane could be separated by column chromatography during the synthesis of a copillar[5]arene. Single crystal X-ray analysis revealed that this [3]pseudorotaxane consisted of the copillar[5]arene and its monomer in a molar ratio of 2 : 1.

Journal: :Chemical communications 2012
Tomoki Ogoshi Daiki Yamafuji Takamichi Aoki Tada-aki Yamagishi

A [2]rotaxane constructed from a per-ethylated pillar[6]arene as a wheel and a pyridinium derivative as an axle was prepared. The wheel segment of the per-ethylated pillar[6]arene moved from one station to another along the axle as a result of thermal stimuli.

Journal: :Chemical communications 2011
Tomoki Ogoshi Keisuke Kitajima Shuhei Fujinami Tada-aki Yamagishi

The reaction of 1,4-dimethoxybenzene and paraformaldehyde using AlBr(3) yields multiple-deprotected pillar[5]arenes. A1/B2 di-deprotected pillar[5]arene can be isolated by silica gel chromatography and washing procedures. The X-ray structure and polymerization of the A1/B2 di-deprotected pillar[5]arene are reported.

Journal: :Chemical communications 2015
James W Walton Jonathan M J Williams

We present nucleophilic aromatic substitution of unsubstituted aryl chlorides via a mechanism that is catalytic in [CpRu(p-cymene)]PF6 and involves a Ru(η(6)-arylchloride) intermediate. From the spectroscopic evidence we infer that arene exchange is the rate limiting step in this process and develop several new Ru(ii) complexes that lower the activation barrier to arene exchange.

Journal: :Organic letters 2013
Chia-Chen Tsai Ying-Tsai Cheng Li-Ching Shen Kai-Chi Chang I-Ting Ho Jean-Ho Chu Wen-Sheng Chung

A biscalixarene framework, without long alkyl chains, has been readily synthesized in three steps starting from the parent calix[4]arene. The biscalix[4]arene 1 was able to form organogels in various alcoholic solvents; furthermore, it exhibited an excellent phase selective gelation property that is potentially useful in oil spill recovery.

Journal: :Chemical communications 2012
Carl Redshaw Mark R J Elsegood Joseph A Wright Hugo Baillie-Johnson Takehiko Yamato Stephen De Giovanni Anja Mueller

Vanadyl bearing calix[4]arene ligands have undergone evaluation against several cell lines, and show varying degrees of toxicity. For vanadyl complexed to a sulfonylcalix[4]arene, monitoring of the strong blue fluorescence revealed slow uptake kinetics. The complex is exclusively found in the cytoplasm of the cells and uptake is not due to active endocytotic mechanisms.

Journal: :international journal of environmental research 0
h. bagheri sadeghi department of chemistry, islamic azad university, central tehran branch, tehran, iran h. sid kalal department of waste management, nfrs, nuclear science and technology institute, aeoi, p. o. box 11365-3486, tehran, iran h. hoveidi graduate faculty of environment, university of tehran, p.o. box 14155-6135, tehran, iran z. molavi department of chemistry, islamic azad university, central tehran branch, tehran, iran n. adeli asl graduate faculty of environment, university of tehran, p.o. box 14155-6135, tehran, iran

a new cesium ion selective pvc membrane based on parent calix [4] arene was developed for potentiometric determination of cesium in environmental samples. the electrode based on p-5,11,17,23tetra(tertbutyl) 25,26,27,28-tetrahydroxy calix[4]arene(thc) as ionophor ,dibutyl phthalate (dbp)as plasticizer ,sodium tetra phenyl borate(natpb)and oleic acid as lipophilic salt and additive showed the bes...

2002
Larry E. Overman Carolyn E. Owen G. Greg Zipp

Planar chiral h6-arene chromium(0) complexes are finding increasing application in the synthesis of enantioenriched compounds by serving as enantiopure starting materials or ligands for catalytic asymmetric processes.[1,2] Whereas early methods of generating enantiopure 1,2-disubstituted h6-arene chromium(0) complexes relied on resolution of racemates,[3] many methods have been developed recent...

Journal: :Chemical communications 2012
Bernd Schmidt Nelli Elizarov

A sequence of acetamide directed oxidative Heck reaction and deacetylation-diazotation-Heck coupling allows the traceless removal of the acetamide group and its dual exploitation as a catalyst directing group and a leaving group.

Journal: :Journal of the American Chemical Society 2010
Amanda E King Lauren M Huffman Alicia Casitas Miquel Costas Xavi Ribas Shannon S Stahl

Recent studies have highlighted the ability of Cu(II) to catalyze the aerobic oxidative functionalization of C-H bonds; however, very little is known about the mechanisms of these reactions. Here, we describe the Cu(II)-catalyzed C-H methoxylation and amidation of a macrocylic arene substrate with O(2) as the stoichiometric oxidant. Kinetic and in situ spectroscopic studies demonstrate the invo...

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