PdII-mediated integration of isocyanides and azide ions might proceed via formal 1,3-dipolar cycloaddition between RNC ligands and uncomplexed azide
Reaction between equimolar amounts of trans-[PdCl(PPh3)2(CNR)][BF4] (R = t-Bu 1, Xyl 2) and diisopropylammonium azide 3 gives the tetrazolate trans-[PdCl(PPh3)2(N4t-Bu)] (67%, 4) or trans-[PdCl(PPh3)2(N4Xyl)] (72%, 5) complexes. 4 and 5 were characterized by elemental analyses (C, H, N), HRESI+-MS, 1H and 13C{1H} NMR spectroscopies. In addition, the structure of 4 was elucidated by a single-crystal X-ray diffraction. DFT calculations showed that the mechanism for the formal cycloaddition (CA) of N3− to trans-[PdCl(PH3)2(CNMe)]+ is stepwise. The process is both kinetically and thermodynamically favorable and occurs via the formation of an acyclic NNNCN-intermediate. The second step of the fo…
ChemInform Abstract: Metal-Free Regioselective C-C Bond Cleavage in 1,3,5-Triazine Derivatives of β-Diketones.
The reaction of cyanuric chloride (I) with 3 equivalents of ketones (II) in the presence of 3 equivalents of KOH affords adducts (IV), which are converted into deacylated derivatives (III) by treatment with aqueous HCl solution in MeOH.
Aqua complex of iron(III) and 5-chloro-3-(2-(4,4-dimethyl-2,6- dioxocyclohexylidene) hydrazinyl)-2-hydroxybenzenesulfonate: Structure and catalytic activity in Henry reaction
Abstract A water-soluble iron(III) complex [Fe(H2O)3(L)]·5H2O (1) was prepared by reaction of iron(III) chloride with 5-chloro-3-(2-(4,4-dimethyl-2,6-dioxocyclohexylidene)hydrazinyl)-2-hydroxy-benzenesulfonic acid (H3L). The complex was characterized by IR, 1H NMR and ESI-MS spectroscopies, elemental and X-ray crystal structural analyses. The coordination environment of the central iron(III) is a distorted octahedron, three sites being occupied by L3− ligand, which chelates in O,N,O fashion, while three other sites are filled with the water molecules. The uncoordinated water molecules are held in the channels of the overall 3D supramolecular structure by the carbonyl and sulfonyl groups of …
Palladium-ADC complexes as efficient catalysts in copper-free and room temperature Sonogashira coupling
Abstract The metal-mediated coupling between cis-[PdCl2(CNR1)2] [R1 = cyclohexyl (Cy) 1, t-Bu 2, 2,6-Me2C6H3 (Xyl) 3, 2-Cl-6-MeC6H3 4] and hydrazones H2NN CR2R3 [R2, R3 = Ph 5; R2, R3 = C6H4(OMe-4) 6; R2/R3 = 9-fluorenyl 7; R2 = H, R3 = C6H4(OH-2) 8] provided carbene complexes cis-[PdCl2{C(N(H)N CR2R3) N(H)R1}(CNR1)] (9–24) in good (80–85%) yields. Complexes 9–24 showed high activity [yields up to 99%, and turnover numbers (TONs) up to 3.7 × 104] in the Sonogashira coupling of various aryl iodides with a range of substituted aromatic alkynes without the need of copper co-catalyst. The catalytic procedure runs at 80 °C for 1 h in EtOH using K2CO3 as a base. No formation of homocoupling or ac…
Syntheses, Structure, and Reactivity of Chiral Titanium Compounds: Procatalysts for Olefin Polymerization
Titanium complexes with chelating alkoxo ligands have been synthesised with the aim to investigate titanium active centres in catalytic ethylene polymerisation. The titanium complexes cis-[TiCl2(η2-maltolato)2] (1, 89 %), and cis-[TiCl2(η2-guaiacolato)2] (2, 80 %) were prepared by direct reaction of TiCl4 with maltol and guaiacol in toluene. The addition of maltol to [Ti(OiPr)4] in THF results in the formation of species [Ti(OiPr)2(maltolato)2] (3, 82 %). The titanium compound cis-[Ti(OEt)2(η2-maltolato)2] (4, 74 %) was obtained by the transesterification reaction of species 3 with CH3CO2Et. When compound 4 is dissolved in THF a dinuclear species [Ti2(μ-OEt)2(OEt)4(η2-maltolato)2] (5, 45 %)…
New Microbe Killers: Self-Assembled Silver(I) Coordination Polymers Driven by a Cagelike Aminophosphine
New Ag(I) coordination polymers, formulated as [Ag(µ
Metal-free regioselective C–C bond cleavage in 1,3,5-triazine derivatives of β-diketones
Metal-free regioselective activation of a carbon–carbon bond in 1,3,5-triazine derivatives of β-diketones is easily achieved, in the absence of a catalyst, with the assistance of intramolecular hydrogen bonding.
CCDC 880877: Experimental Crystal Structure Determination
Related Article: Maximilian N. Kopylovich, Kamran T. Mahmudov, Matti Haukka, Armando J. L. Pombeiro|2014|New J.Chem.|38|495|doi:10.1039/C3NJ01292A
CCDC 880876: Experimental Crystal Structure Determination
Related Article: Maximilian N. Kopylovich, Kamran T. Mahmudov, Matti Haukka, Armando J. L. Pombeiro|2014|New J.Chem.|38|495|doi:10.1039/C3NJ01292A
CCDC 1414621: Experimental Crystal Structure Determination
Related Article: Mikhail A. Kinzhalov, Alexander S. Novikov, Konstantin V. Luzyanin, Matti Haukka, Armando J. L. Pombeiro, Vadim Yu. Kukushkin|2016|New J.Chem.|40|521|doi:10.1039/C5NJ02564H