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A series of the functionalised pillar[5]arene ureidopyrimidinone derivatives were successfully synthesised by the condensation reaction of mono-amido-functionalised pillar[5]arenes with 2-(1-Imidazolylcarbonylamino)-6-methyl-4-pyrimidinone in dry chloroform. 1H NMR, 2D NOESY spectra and single crystal structure clearly indicated that novel [1]rotaxanes were formed by insertion of longer alkylene chain into the cavities of the pillar[5]arenes. On the other hand, the ureidopyrimidinone-functionalised pillar[5]arenes tend to form the dimer in chloroform and in solid state through the self-complementary quadruple hydrogen bonding of the ureidopyrimidinone. [ABSTRACT FROM AUTHOR]

Series of novel p-tert-butyldihomooxacalix[4]arene mono-Schiff bases including dithiocarbonylhydrazones and dicarbonohydrazones were conveniently synthesized by condensation reaction of p-tert-butyldihomooxacalix[4]arene O-alkoxy-substituted benzaldehydes with benzyl hydrazinecarbodithioate and N'-(2-hydroxybenzylidene)hydrazinecarbohydrazide. More importantly, the similar condensation of p-tert-butyldihomooxacalix[4]arene mono-substituted benzaldehydes with various N,N′-alkylenebis(hydrazinecarbothioamides) afforded interesting dithiosemicarbazone-bridged bis(p-tert-butyldihomooxacalix[4]arenes). [ABSTRACT FROM AUTHOR]

A series of novel functionalized p-tert-butyldihomooxacalix[4]arene mono-Schiff bases were conveniently synthesized by two-step reaction process. The synthetic rout included alkylation of p-tert-butyldihomooxacalix[4]arene with O-chloroalkoxy-substituted benzaldehydes and sequential condensation with 2-hydroxybenzohydrazide, 2-picolinohydrazideand aminothiourea. The single crystal structures of two p-tert-butyldihomooxacalix[4]arenederivatives were determined by X-ray single crystal diffraction method. The coordination abilities of dihomooxacalix[4]arene mono-Schiff bases towards transition metal ions were preliminarily investigated by UV-Vis spectra. [ABSTRACT FROM AUTHOR]

The addition reaction of mono-amide-functionalized pillar[5]arenes with 1,4-diisothiocyanatobenzene or 1,4-diisothiocyanatohexane in chloroform resulted in various dithioureado-bridged bis-pillar[5]arenes. 1H and 2D NMR spectroscopy as well as X-ray single crystal structure indicated that the longer dithioureado chain threaded into both cavities of the two pillar[5]arenes to form the unique bis-[1]rotaxane structures in solution and in solid state. [ABSTRACT FROM AUTHOR]

A series of thiourea-functionalised pillar[5]arene derivatives3nmwere constructed from a series of mono-amide-functionalised pillar[5]arenes2n. The formation of their free forms or (pseudo)[1]rotaxane structures were controlled by their axle lengths or solvents, which were investigated by1H NMR spectroscopy. Some of (pseudo)[1]rotaxane structures were also supported by their single-crystal structures. [ABSTRACT FROM AUTHOR]

A series ofp-tert-butylcalix[4]arene 1,3-diimidazolium salts were successfully prepared by the alkylation ofp-tert-butylcalix[4]arene with dibromoalkanes, and sequential substitution reaction with 1-alkylimidazole. Furthermore, coordination reactions ofp-tert-butylcalix[4]arene 1,3-diimidazolium salts with silver oxide and mercury acetate gave novel Ag and Hg complexes of bis(N-heterocyclic carbenes) onp-tert-butylcalix[4]arene platform. The single-crystal structures of fourp-tert-butylcalix[4]arene 1,3-diimidazolium salts and three metal complexes were successfully determined by X-ray diffraction. An Ag–Ag argentophilic interaction (Ag–Ag bond length is 3.1599(6) Å) is formed between the two Ag–NHC complexes and a dimetallic coordination mode exists in Hg–NHC complexes. [ABSTRACT FROM PUBLISHER]

A simple and efficient synthesis of ammonium 3,5-dicyano-4-aryl-2,6-pyridinedionates was accomplished via one-pot, three-component reaction of aromatic aldehydes, amines, and cyanoacetamide. This unprecedented methodology had some potential advantages such as the common available starting material, short reaction time, good yield, broad substrate scope, and convenient operation. [ABSTRACT FROM PUBLISHER]

The calix[4]arene-based podand which incorporates two terpyridine functions in 1,3-alternate positions with flexible propylene spacers at lower rim has been prepared and subjected to complexation studies with some transition metal ions. Single-crystal structures of Mn(II), Co(II), and Zn(II) complexes were determined by X-ray diffraction. These metal complexes are formed with a 2 : 1 ratio of metal and ligand. Coordination of each metal is five-coordinate distorted trigonal-bipyramidal geometry by three nitrogen atoms from a terpyridyl unit and two chloride atoms. [ABSTRACT FROM AUTHOR]

[image omitted] Under microwave irradiation, the one-pot multicomponent condensation reaction of three molar aromatic aldehydes with two molar cyclic ketones having free α,α'-methylene positions such as cyclopentanone or cyclohexanone in the presence of ammonium acetate and acetic acid afforded dicyclocalkenopyridines with two α-arylidene groups in good yields. In similar reaction conditions, 1-tetralone, which has only one α-methylene position, results in 10-aryl-2,3:5,6-dibenzoacridines. [ABSTRACT FROM AUTHOR]

Under microwave irradiation, vanillin was alkylated with α,ω-dihaloalkane to give 4,4'-alkylene-bridging vanillins, which in turn underwent one-pot multicomponent reactions with excess of ethyl acetoacetate and ammonium bicarbonate to give 4,4'-alkoxy-bridging bisdihydropyridines in moderate yields. The structures of the synthetic bisdihydropyridines were characterized with 1H NMR, 13C NMR, and high-performance liquic chromatography/mass spectroscopy. [ABSTRACT FROM AUTHOR]

The calix[4]arene-based podand, which incorporates two Schiff-base functions derived from S-alkyldithiocarbazate in 1,3-alternate positions on the lower rim has been prepared and reacted with transition metal ions. X-ray single crystal diffraction of nickel and copper complexes shows that two iminothiolate domains are monoanionic bidentate planar chelators to coordinate one metal in distorted tetrahedral geometry. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

A dicopper complex of p-tert-butylcalix8arene bearing eight salicylaldehyde acylhydrazone domains was prepared and its single crystal structure determined, in which only four acylhydrazone domains act as monoanionic tridentate planar chelators to coordinate to two copper ions. [ABSTRACT FROM AUTHOR]

Acetoacetylferrocene reacted with benzidine and 4,4'-diaminodiphenylmethane in absolute ethanol to give the diketoimines 2a-b in high yields. Determined by X-ray structure analysis, 2a crystallized in monoclinic crystal system - space group P21/c with cell parameters: a=10.8595(2), b=12.4095(2), c=12.2021(2) Å, β=97.6390(10), Z=2, V=1631.10(5) Å3. The unit cell contains two independent molecules to form helical crystal structure stabilized by hydrogen bond interactions with helical angle is 39.3°. [ABSTRACT FROM AUTHOR]

Lead acetate reacts with 2-pyridinecarboxadehyde isophthalylhydrazone (H2pcph) giving a dinucleic [Pb2(pcph)Ac2] complex. As shown by X-ray crystal analysis, each lead ion is coordinated by one hydrazide nitrogen, one pyridine nitrogen, one carbonyl oxygen, and one acetate oxygen, giving rise to a unusually N2O2 distorted planar square coordination geometry. [ABSTRACT FROM AUTHOR]

Bimetallic complexes 3a-e of 1,1'-bisacetylacetoferrocene (2) were prepared by reactions of transition metal acetates M(OAc)2 (M = Co2+, Mn2+, Cu2+, Ni2+, Zn2+) with the 2 in refluxing methanol. The X-ray structures of the cobalt and manganese complexes were determined showing very similar centrosymmetric macrocyclic dimeric frameworks constituted by linkage of two Co2+ or Mn2+ ions and two 1,1'-diacetoacetylferrocene units with two additional methanols as bridges dividing this macrocyclic framework into two small cyclic subunits. The UV-Vis spectra and electronic properties were also studied. [ABSTRACT FROM AUTHOR]

In a system of ammonium acetate and acetic acid under microwave irradiation, N-phenacylpyridinium chloride 1 reacted with 2 mol of aromatic aldehydes 2a–h to give 2,4,6-triarylpyrimidine 3a–h, reacted with pyridinecarboxaldehyde 4a–c and acetophenone 5 to yield bipyridine derivatives 6a–c. The structure of the products was characterized with 1H NMR, 13C NMR, IR, and mass spectroscopy. [ABSTRACT FROM AUTHOR]

In the solid–liquid system of potassium hydroxide as base and polyethylene glycol (PEG-400) as phase transfer catalyst, 2-furfuryl alcohol reacts with a family of alkylene dihalides (CH2, (CH2)4, (CH2)5, CH2CH2OCH2CH2) in refluxing benzene to yield furfuryl diethers in good yield (61–82%). [ABSTRACT FROM AUTHOR]

In the presence of KF-Al2O3 as a solid base, 2-methylbenzoxazole 1 in DMF and 1-phenyl-3-methylpyrazol-5-one 2 in methanol, respectively, reacted with aromatic aldehydes to give 2-styrylbenzoxazoles 4a–f in high yields and 1-phenyl-3-mehtyl-4-arylmethylenepyrazol-5-ones 5a–f in moderate yields. [ABSTRACT FROM AUTHOR]