Hydrogenation of terminal and internal olefins using a biowaste-derived heterogeneous cobalt catalyst

Hydrogenation of olefins is achieved using biowaste-derived cobalt chitosan catalysts. Characterization of the optimal Co@Chitosan-700 by STEM (scanning transmission electron microscopy), EELS (electron energy loss spectroscopy), PXRD (powder x-ray diffraction), and elemental analysis revealed the formation of a distinctive magnetic composite material with high metallic Co content. The general performance of this catalyst is demonstrated in the hydrogenation of 50 olefins including terminal, internal, and functionalized derivatives, as well as renew-ables. Using this nonnoble metal composite, hydrogenation of terminal C==C double bonds occurs under very mild and benign conditions (water or methanol, 40\ub0 to 60\ub0C). The utility of Co@Chitosan-700 is showcased for efficient hydrogenation of the industrially relevant examples diisobutene, fatty acids, and their triglycerides. Because of the magnetic behavior of this material and water as solvent, product separation and recycling of the catalyst are straightforward

Crystal structures of 1-2-(dicyclohexylphosphinophenyl)pyrol-2- dicyclohexylphosphino-rhodium(I) norborna-2,5-diene tetrafluoroborate tetrahydrofuran hemisolvate, [Rh(C34H5INP 2)(C7H8)] [BF4] · 0.5C 4H8O, and 1-2-(dicyclohexylphosphinophenyl)-pyrol-2- dicyclohexylphosphino-rhodium(I) (Z,Z)-cycloocta...

Title full: Crystal structures of 1-2-(dicyclohexylphosphinophenyl)pyrol-2- dicyclohexylphosphino-rhodium(I) norborna-2,5-diene tetrafluoroborate tetrahydrofuran hemisolvate, [Rh(C34H5INP 2)(C7H8)] [BF4] · 0.5C 4H8O, and 1-2-(dicyclohexylphosphinophenyl)-pyrol-2- dicyclohexylphosphino-rhodium(I) (Z,Z)-cycloocta-1,5-diene tetrafluoroborate, [Rh(C34H5INP2)(C8H12)] [BF4]. C43H63BF4NO0.50P2 Rh, monoclinic, P121/n1 (no. 14), a = 10.341(2) Å, b = 16.063(3) Å, c = 27.425(5) Å, β = 98.76(3)°, V= 4502.4 Å3, Z = 4, Rgt(F) = 0.060, wRref(F 2) = 0.143, T = 200 K. C42H63BF 4NP2Rh, monoclinic, P121/c1 (no. 14), a = 10.503(2) Å, b = 17.665(4) Å, c = 21.946(4) Å, β = 101.95(3)°, V= 3983.5 Å3, Z = 4, Rgt(F) = 0.045, wRref(F2) = 0.013, T =200 K. © by Oldenbourg Wissenschaftsverlag,

Selective palladium-catalysed synthesis of diesters: alkoxycarbonylation of a CO2-butadiene derived delta-lactone

Novel unsaturated C-10 diesters are produced via the alkoxycarbonylation of delta-lactone 1 (3-ethylidene-6-vinyltetrahydro-2H-pyran-2-one), derived from the telomerization of CO2 and butadiene. The key for the selective valorization of 1 is the use of a catalytic system based on PdCl2, a chelating phosphine bearing electron-withdrawing groups and an acidic promoter. The unsaturated C-10 methyl diester can be easily hydrogenated on Pd/C under mild conditions to afford its corresponding saturated diester. Subsequent hydrogenation using the homogeneous [Ru(acac)(3)]/Triphos catalysts gives 2-ethyloctane-1,8-diol in high yield. The overall procedure allows synthesizing new building blocks for the manufacturing of renewable polymers and polymer processing materials

Functional Elastomers via Sequential Selective Diene Copolymerization / Hydrophosphorylation Catalysis

International audienc

Efficient Dehydrogenation of Formic Acid Using an Iron Catalyst

Hydrogen is one of the essential reactants in the chemical industry, though its generation from renewable sources and storage in a safe and reversible manner remain challenging. Formic acid (HCO2H or FA) is a promising source and storage material in this respect. Here, we present a highly active iron catalyst system for the liberation of H2 from FA. Applying 0.005 mole percent of Fe(BF4)2·6H2O and tris[(2-diphenylphosphino)ethyl]phosphine [P(CH2CH2PPh2)3, PP3] to a solution of FA in environmentally benign propylene carbonate, with no further additives or base, affords turnover frequencies up to 9425 per hour and a turnover number of more than 92,000 at 80°C. We used in situ nuclear magnetic resonance spectroscopy, kinetic studies, and density functional theory calculations to explain possible reaction mechanisms

Efficient catalysts for telomerization of butadiene with amines

In situ-generated N-heterocyclic carbene (NHC) palladium catalysts and isolated NHC-palladium complexes have been tested for the telomerization reaction of 1,3-butadiene with primary and secondary amines. Superior catalyst activity (TON up to 400.000) and selectivity are obtained. Applying optimized conditions a variety of octa-2,7-dienylamines were prepared in high yield and excellent selectivity