共查询到20条相似文献,搜索用时 0 毫秒
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Muriel Funck 《Tetrahedron letters》2010,51(49):6399-6402
A series of resorcin[4]arene and pyrogallol[4]arene macrocycles have been synthesized efficiently within 5 min, affording crystalline products suitable for single crystal X-ray diffraction, utilising microwave irradiation in a ‘one-pot’ reaction whilst controlling the selective formation of the rccc cone stereoisomer. 相似文献
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Takehiko Yamato Carol Pérez-Casas Shofiur Rahman Zeng Xi Mark R. J. Elsegood Carl Redshaw 《Journal of inclusion phenomena and macrocyclic chemistry》2007,58(1-2):193-197
A novel receptor possessing two complexation sites and bearing 1,3-alternate conformation based on thiacalix[4]arene, confirmed by single crystal X-ray analysis, was prepared. The tetrathiacalix[4]arene
diamide shows strong intramolecular hydrogen bonding. The binding behavior towards K+ and halides has been examined by 1H NMR titration experiments. 相似文献
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The preparation of an 1,3-alternate calix[4]arene phosphorus ligand, 25,27-bis(2-(diphenylphosphino)ethoxy)-26,28-bis(1-propyloxy)calix[4]arene (3), is presented. Ligand 3 is obtained in three steps in 64% overall yield. Reaction of 3 with [Rh(cot)2]BF4 produced the encapsulated rhodium complex [Rh[(P,P)-diphen-calix[4]arene]]BF4 (4). As revealed by a single-crystal X-ray diffraction study, the rhodium center has a bent coordination environment with a P-Rh-P angle of 135.66(3) degrees. Palladation of 3 employing [Pd(MeCN)4](BF4)2 yielded the chelate palladium complex 7 in which the palladium center has a slightly bent configuration. Treatment of the ligand with Pd(cod)Cl2 and [Pd(eta3-C4H7)(THF)2]BF4 leads to the isolation of the monometallic complex. Full characterization includes X-ray structural studies of compounds 3, 4, and 6. 相似文献
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《Journal of Coordination Chemistry》2012,65(13):2118-2124
The calix[4]arene-based podand which incorporates two salicylideneamine units in 1,3-alternate positions of the lower rim has been prepared and subjected to complexation studies with transition metal ions. The nickel and copper complexes form a 2 : 2 stoichiometric metallic macrocyclic framework. 相似文献
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Seri N Simaan S Botoshansky M Kaftory M Biali SE 《The Journal of organic chemistry》2003,68(18):7140-7142
The use of a chiral solvating agent enabled the determination of the NMR-silent ring-inversion process of the ketocalixarene 3. Spectroscopic and crystal data indicate that 3 adopts the unusual 1,3-alternate conformation. 相似文献
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Possible rearrangement mechanisms of hydrogen-bond arrays formed at the lower rim of tetrahydroxycalix[4]arene and tetrahydroxythiacalix[4]arene were studied by means of density functional theory and the resolution identity approximation modification of M?ller-Plesset perturbation theory (RI-MP2). Influence of solvent to height of energy barriers was quantified by use of the conductorlike screening model (COSMO) of implicit solvent (chloroform). Generally, two types of mechanisms were investigated. The first is represented by a synchronous single-step jump of all four hydroxyl protons. Pathways of the second mechanism include the rotation of one or more hydroxyl groups around the CAr-O bond. Theoretical results, in agreement with recently published experimental data (Lang et al. J. Chem. Phys. 2005, 122, 044056), prefer a jump mechanism for the methylene-bridged calix[4]arene. Concerning the thiacalix[4]arene, results obtained by COSMO as well as RI-MP2 calculations show that the rotational mechanism is very competitive and it could even be more favorable. 相似文献
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<正>Refluxing calix[4]-1,3-substituted benzaldehyde derivative(4) with glycine hydrazide derivative,we obtained a novel calix[4]arene hydrazone derivative(5) via"1+2"condensation in a yield of 78%.In the reaction of compound 4 with L-leucine hydrazide derivative at room temperature,lariat calix[4]-1,3-aza-crown(6) with chiral amino acid group as branched chain was synthesized via"1+1"addition in a yield of 70%.The preliminary extraction experiments suggested that hosting compounds 5 and 6 possessed good complexation abilities forα-amino acids. 相似文献
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The synthesis of calix[4]arene based dendrimers containing up to seven calix[4]arene moieties is described, including the X-ray crystal structure of a tris-calix[4]arene branching derivative. 相似文献
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Víctor García-López Jovana V. Milić Michal Zalibera Dmytro Neshchadin Martin Kuss-Petermann Laurent Ruhlmann Julia Nomrowski Nils Trapp Corinne Boudon Georg Gescheidt Oliver S. Wenger François Diederich 《Tetrahedron》2018,74(39):5615-5626
A light-actuated resorcin[4]arene cavitand equipped with two quinone (Q) and two opposite Ru(II)-based photosensitizing walls was synthesized and investigated. The cavitand is capable of switching from an open to a contracted conformation upon reduction of the two Q to the corresponding SQ radical anions by intramolecular photoinduced electron transfer in the presence of a sacrificial donor. The molecular switch was investigated by cyclic and rotating disc voltammetry, UV–Vis–NIR spectroelectrochemistry, transient absorption, NMR, and EPR spectroscopy. This study provides the basis for the development of future light-activated switches and molecular actuating nanodevices. 相似文献
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Arisa Jaiyu 《Tetrahedron letters》2007,48(10):1817-1821
A series of stilbene-bridged calix[4]arenes was synthesized through an intramolecular reductive McMurry coupling of bisbenzaldehyde calix[4]arene in high yields. Tetra- and pentaethylene glycol chains were tethered to the phenolic groups of calix[4]arene to form stilbene-bridged calix[4]arene crown-5 and crown-6, respectively. The presence of stilbene bridge over the calix[4]arene rim effectively prevented the connection of the polyether chains in the cone conformation resulting in the exclusive formation of 1,3-alternate stilbene-bridged calix[4]arene crown product. Compared to the cone analogues, the 1,3-alternate calix[4]arene crown ethers showed a greater extraction ability and selectivity toward Cs+. 相似文献
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St'astný V Stibor I Císarová I Sýkora J Pojarová M Lhoták P 《The Journal of organic chemistry》2006,71(14):5404-5406
A novel type of doubly bridged thiacalix[4]arenes in the 1,3-alternate conformation has been prepared by direct aminolysis reaction of easily accessible thiacalix[4]arene tetraacetates with alpha,omega-diamines. Despite the high excess of diamine, both sites of a 1,3-alternate conformer can be intramolecularly bridged to form the cagelike structures in high yields. Optimum results were obtained using 1,2-ethanediamine as bridging units. X-ray analysis of the novel cagelike molecules revealed a highly preorganized array of -C(O)-NH- bonds pointing to the interior of the cavity. 相似文献