Diastereoselective synthesis of cyclohexadienes via tandem cyclization strategies.

A new protocol has been developed for the diastereoselective synthesis of 1,3-cyclohexadienes using vinyl malononitriles, dibenzalacetones and NaH as reagents in THF. This transformation is comprised of interesting steps like Michael addition, cyclization and ring-opening reactions.

Hydrogen-Bonded Organic⁻Inorganic Hybrid Based on Hexachloroplatinate and Nitrogen Heterocyclic Cations: Their Synthesis, Characterization, Crystal Structures, and Antitumor Activities In Vitro.

Three new crystal structures containing [PtCl6]2−, pyridinium and benzimidazole groups have been prepared: [PtCl6]·(H-bzm)2·2(H2O) (1), [PtCl6]·(H-bipy)2·2(H2O) (2), [PtCl6]·(H-dimethyl-bipy)2·2(H2O) (3) [H-bzm: benzimidazole cation, H-bipy: 2,2'-bipyridine cation, H-dimethyl-bipy: 4,4'-bimethyl-2,2'-bipyridine cation]. All compounds have been fully characterized by elemental analyses, single-crystal X-ray analyses, IR spectra, TG analyses, and fluorescence studies. Single-crystal X-ray diffraction analysis suggests that the primary synthon contains ⁺N⁻H···Cl−, including ionic bonding and hydrogen bonding interactions. The dimensions are enhanced further by secondary O⁻H ∙∙Cl and N⁻H ∙∙O hydrogen bonding interactions between donor and acceptor atoms located at the periphery of these synthons. Moreover, coulombic attractions between the ions play an important role in reinforcing the structures of these complexes. In addition, antitumor activity against human lung adenocarcinoma cell line (A549) and human nasopharyngeal carcinoma cell line (CNE-2) was performed. These complexes all showed inhibition to the two cell lines, while complex 3 exhibited higher efficiency than complexes 1⁻2.

Two titanium(iv)-oxo-clusters: synthesis, structures, characterization and recycling catalytic activity in the oxygenation of sulfides.

Two 5-sulfosalicylic acid (H3ssal) and 1,10-phenanthroline (Phen) substituted titanium-oxo-clusters, [Ti6O8 (Hssal)2(Phen)6(H2O)4]·4OH·21H2O (TOC-1) and [Ti4O4(Hssal)4(Phen)4]·18H2O·4NH3 (TOC-2), have been synthesized and fully characterized by single crystal X-ray diffraction, FT-IR spectroscopy, elemental analysis, thermogravimetric analysis and fluorescence analysis. The structure of TOC-1 is a hexanuclear cluster containing a {Ti6(µ2-O)8} core, where all titanium ions can be described in a distorted octahedral geometry with both 1,10-phenanthroline and 5-sulfosalicylate serving as chelating ligands, while TOC-2 consists of a tetranuclear {Ti4(µ2-O)4} skeleton forming an approximate plane quadrilateral where both 5-sulfosalicylate and 1,10-phenanthroline ligands chelate to the titanium atom and the oxygen atom bridges two titanium atoms. Moreover, catalytic activity for the selective oxidation of sulfides, methyl phenyl sulfide (MPS) and phenyl sulfide (PPS), has also been explored. The results showed that TOCs 1 and 2 exhibit excellent catalytic performance in the oxidation of sulfides to sulfoxides with H2O2 as an oxidant. In particular, TOC-1 is an efficient homogeneous catalyst and very interestingly it can be recovered by filtration upon cooling and then reused at least four times without losing activity, which is very rare in the oxygenation of organic sulfides.

Crystal structure of 4,4'-(ethene-1,2-di-yl)dipyridinium bis-(3-carb-oxy-benzene-sulfonate).

In the title mol-ecular salt, C12H12N2 (2+)·2C7H5O5S(-), the complete dication is generated by crystallographic inversion symmetry. In the anion, the sulfonic acid group is deprotonated and the dihedral angle between the planes of the carb-oxy-lic acid group and the benzene ring is 12.41 (11)°. In the crystal, the anions are linked into inversion dimers by pairs of O-H⋯O hydrogen bonds, which generate R 2 (2)(16) loops. The dications link the anion dimers into [10-2] chains via N-H⋯O hydrogen bonds.

Synthesis of heterocyclic [3.3.3]propellanes via a sequential four-component reaction.

A highly chemoselective heteroannulation protocol for the synthesis of unreported polysubstituted heterocyclic [3.3.3]propellanes has been developed by sequential four-component reaction of ninhydrin, malononitrile, primary amines, and dialkyl acetylenedicarboxylates under mild conditions in water. To the best of our knowledge, there are no previous reports for the synthesis of these classes of heterocyclic [3.3.3]propellanes. The merit of this sequential Knoevenagel condensation/enamine formation/Michael addition/cyclization sequence is highlighted by its high atom-economy, excellent yields, the use of water as reaction media, and the efficiency of production without the use of any activator or metal promoters. This synthesis serves as a nice addition to group-assistant-purification (GAP) chemistry in which purification via chromatography and recrystallization can be avoided, and the pure products were obtained simply by washing the crude products with 95% ethanol.

Regiocontrolled [2 + 2] photodimerization of Cd(II) metal complexes in both solution and solid state.

The [2 + 2] photodimerization of Cd(II) 1,2-bis-(4-pyridyl)ethylene complex with a 3-D interpenetration network occurred in both the solid state and in the mixture solution of starting materials upon the irradiation of UV lamp with strong power or sunlight.

Novel three-component route to diastereoselective synthesis of trisubstituted vinylphosphonates using phosphites, acetylenic esters, and aroyl chlorides.

Trisubstituted vinylphosphonates have been prepared via three-component reaction using phosphites, acetylenic esters, and aroyl chlorides in good yields. A variety of phosphites, activated acetylenes, and aroyl chlorides have been successfully employed in these reactions. In addition, three-component synthesis of vinylphosphonate provides exclusive E-olefin stereochemistry.

Syntheses, structures, and characterizations of four new lead(II) 5-sulfosalicylate complexes with both chelating and bridging neutral ligands.

Four structurally diverse complexes, {[Pb(Hssal)(2,2'-bipy)](4,4'-bipy)0.5}n (1), [Pb2(Hssal)2(2,2'-bipy)2(4,4'-bipy)(H2O)2] (2), [Pb(Hssal)(phen)(4,4'-bipy)0.5]n (3), and [Pb(Hssal)(2,2'-bipy)(bpe)0.5]n (4), have been synthesized and characterized by elemental analyses, IR, thermogravimetric analyses, fluorescent spectra, and single-crystal X-ray analyses, where Hssal2- is doubly deprotonated 5-sulfosalicylate, 2,2'-bipy is 2,2'-bipyridine, phen is 1,10-phenanthroline, 4,4'-bipy is 4,4'-bipyridine, and bpe is trans-1,2-bis(4-pyridyl)ethylene. The structure of complex 1 possesses a one-dimensional ladderlike chain with guest 4,4'-bipy molecules, while the molecular structure of complex 2 is a dimeric species with a coordinating 4,4'-bipy ligand. Complex 3 consists of a one-dimensional ladderlike chain with monodentate 4,4'-bipyridine but somewhat different from that of complex 1. Complex 4 is a two-dimensional layer structure. In 1-4, all 5-sulfosalicylates are doubly deprotonated, and all carboxylate groups of Hssal2- chelate to PbII ions; however, the coordination modes of sulfonyl groups are different: syn-syn bridging in 1, noncoordinating in 2, syn-skew bridging in 3, and one-atom bridging in 4. The noncoordinating mode of sulfonate in PbII complexes containing 5-sulfosalicylate is first reported in this presentation. The 4,4'-bipy ligands act as guest molecules in 1, dimeric linkers in 2, and monodentates in 3. The pi-pi stacking interactions can be observed in complexes 1-3, whereas there is no such interaction in complex 4. The coordination spheres of PbII ions in 1-4 are controlled by three factors: the activity of a lone pair of electrons, weak Pb-O interactions, and pi-pi stacking interactions. The PbII lone pair in 4 is inactive, whereas in 1-3, they are stereochemically active. The thermal stability and fluorescent property of complexes 1-4 are different from those of PbII complexes only containing chelating ligands, [Pb(Hssal)(2,2'-bipy)(DMF)]n (5), and [Pb(Hssal)(2,2'-bipy)(H2O)]n (6), and [Pb(Hssal)(phen)(DMF)]n (7).

Influence of the reaction conditions on the self-assembly of lead(II) 5-sulfosalicylate coordination polymers with chelating amine ligands.

The synthesis and crystal structures of [Pb(Hssal)(2,2'-bipy)(DMF)]n (1), [Pb(Hssal)(2,2'-bipy)(H2O)]n (2), [Pb(Hssal)(phen)(DMF)]n (3), and [Pb3(ssal)2(phen)3]n (4) were reported, where Hssal2- and ssal3- are doubly and fully deprotonated 5-sulfosalicylates, 2,2'-bipy is 2,2'-bipyridine, and phen is 1,10-phenanthroline. Compounds 1-4 were synthesized by the various reaction conditions, such as reaction temperature, molar ratio, and pH, and these structures are formed by infinite chains or layers where Pb(II) ions are linked by Hssal2- or ssal3- bridges. Compound 1, which has a ladderlike chain, was formed in DMF/H2O. Compound 2 with a H2O molecule coordinated to Pb(II) was prepared by a hydrothermal reaction. Compounds 3 and 4 were synthesized in a higher pH compared to compounds 1 and 2, containing the 2,2'-bipy ligand. In 1-3, 5-sulfosalicylates are doubly deprotonated, whereas in 4, 5-sulfosalicylate is fully deprotonated. Coordination modes of Hssal2- and ssal3- ligands in 1-4 are novel and are first reported in this presentation. Although compounds 1 and 3 have the same structural topology, their aromatic-aromatic interactions are significantly different. The coordination spheres of Pb(II) ions in 1 and 3 are holodirected, whereas in 2 and 4, they feature somewhat hemidirected properties with small holes or gaps. Compound 4 exhibits some interesting features that (1) there is not any solvent in the structure, (2) there are extensively aromatic-aromatic stacking interactions among aromatic rings, and (3) there is also a weak interaction between Pb(II) atoms in the trinuclear motif.

A one-dimensional mixed-anion lead(II) coordination polymer: catena-poly[[(1,10-phenanthroline)lead(II)]-mu-benzoato-mu-nitrato-[(1,10-phenanthroline)lead(II)]-di-mu-benzoato].

In the title polymeric compound, [Pb2(C7H5O2)3(NO3)(C12H8N2)2]n, both independent Pb atoms adopt an eight-coordinate geometry formed by one nitrate, three benzoate and one 1,10-phenanthroline ligand. The one-dimensional polymer consists of dimeric [Pb2(C7H5O2)3(NO3)(C12H8N2)2] units, in which all nitrate and benzoate ligands act in a bridging-chelating coordination mode.

A mixed-valence CuII/CuI anion-cation complex: bis[mu-5-sulfosalicylato(3-)]bis[(di-2-pyridylamine)copper(II)] bis[bis(di-2-pyridylamine)copper(I)] dihydrate.

The title compound, [CuII(2)(C7H3O6S)2(C10H9N3)2][CuI(C10H9N3)2]2.2H2O, consists of anionic CuII moieties, cationic CuI species and uncoordinated water molecules. The anionic dimeric unit consists of one crystallographically independent fully deprotonated 5-sulfosalicylate (2-oxido-5-sulfonatobenzoate) anion, a di-2-pyridylamine group and a CuII atom. Each CuII atom is five-coordinate within a square-pyramidal geometry. The anion lies on a special position of -1 site symmetry. In the cationic monomer, the CuI atom adopts tetrahedral geometry. The cations and anions are connected by O-H...O and N-H...O hydrogen bonds.

Poly[[mu2-aqua-bis[(1,10-phenanthroline)nickel(II)]]-di-mu2,mu4-5-nitro-1,3-benzenedicarboxylato].

The reaction of Ni(CH(3)COO)(2).4H(2)O, 5-nitro-1,3-benzenedicarboxylic acid (H(2)nmbdc), 1,10-phenanthroline and water under hydrothermal conditions yields the first reported two-dimensional nickel coordination polymer with water- and carboxylate-bridged dimeric units, viz. [Ni(2)(C(8)H(3)NO(6))(2)(C(12)H(8)N(2))(2)(H(2)O)](n). The coordination polyhedron of the Ni(II) ion in the title structure is an octahedron defined by an N(2)O(4) donor set. The water molecule is positioned on a mirror plane and the 5-nitro-1,3-benzenedicarboxylate group is located on a twofold axis. Two types of nmbdc(2-) coordination mode are observed: one is a bis-monodentate mode, mu(2)-nmbdc(2-), and the other is a bis-bridging mode, mu(4)-nmbdc(2-). The dimeric unit in the title compound is similar to the structural moiety in urease. In the two-dimensional framework in the title compound, strong stacking interactions between benzene rings (mu(2)-nmbdc(2-) and mu(4)-nmbdc(2-)) and 1,10-phenanthroline ligands are observed.

Tetraaqua(2,2'-bipyridine)nickel(II) terephthalate.

The reaction of nickel(II) nitrate with terephthalic acid and 2,2'-bipyridine in dimethylformamide solution gives the title complex, [Ni(C(10)H(8)N(2))(H(2)O)(4)](C(8)H(4)O(4)). The Ni(II) ion is octahedrally coordinated to one 2,2'-bipyridine and four water molecules and does not coordinate to the terephthalate anion. Hydrogen bonds between the terephthalate anions and the [Ni(2,2'-bipy)(H(2)O)(4)](2+) cations produce a two-dimensional hydrogen-bonding architecture with double sheets.