108-64-5Relevant articles and documents
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Bone,Sprankling
, p. 654 (1900)
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Copper-catalyzed conjugate addition of organomagnesium reagents to α,β-ethylenic esters: A simple high yield procedure
Cahiez, Gerard,Alami, Mouad
, p. 7425 - 7428 (1990)
The conjugate addition of organomagnesium reagents to α, β-ethylenic esters is performed in THF, at room temperature (30 min to 1.5 h), in the presence of CuCl (3%) and Me3SiCl (1.2 eq.). Good yields of 1,4-addition products are obtained according to this very simple procedure.
Catalytic hydrogenation activity and electronic structure determination of bis(arylimidazol-2-ylidene)pyridine Cobalt Alkyl and Hydride Complexes
Yu, Renyuan Pony,Darmon, Jonathan M.,Milsmann, Carsten,Margulieux, Grant W.,Stieber, S. Chantal E.,Debeer, Serena,Chirik, Paul J.
, p. 13168 - 13184 (2013)
The bis(arylimidazol-2-ylidene)pyridine cobalt methyl complex, ( iPrCNC)CoCH3, was evaluated for the catalytic hydrogenation of alkenes. At 22 C and 4 atm of H2 pressure, ( iPrCNC)CoCH3 is an effective precatalyst for the hydrogenation of sterically hindered, unactivated alkenes such as trans-methylstilbene, 1-methyl-1-cyclohexene, and 2,3-dimethyl-2-butene, representing one of the most active cobalt hydrogenation catalysts reported to date. Preparation of the cobalt hydride complex, (iPrCNC)CoH, was accomplished by hydrogenation of (iPrCNC)CoCH3. Over the course of 3 h at 22 C, migration of the metal hydride to the 4-position of the pyridine ring yielded (4-H2-iPrCNC)CoN2. Similar alkyl migration was observed upon treatment of (iPrCNC)CoH with 1,1-diphenylethylene. This reactivity raised the question as to whether this class of chelate is redox-active, engaging in radical chemistry with the cobalt center. A combination of structural, spectroscopic, and computational studies was conducted and provided definitive evidence for bis(arylimidazol-2- ylidene)pyridine radicals in reduced cobalt chemistry. Spin density calculations established that the radicals were localized on the pyridine ring, accounting for the observed reactivity, and suggest that a wide family of pyridine-based pincers may also be redox-active.
Green syntheses of biobased solvents
Bandres, Matthieu,De Caro, Pascale,Thiebaud-Roux, Sophie,Borredon, Marie-Elisabeth
, p. 636 - 646 (2011)
The design of bioproducts implies the use of renewable carbon but also the conversion of this carbon through clean processes. This step is often a limiting one if we consider the whole life cycle "from the raw materials to the fate of the products". We proposed, in this work, to adapt conventional methods to the conversion of a natural raw material, the fusel oil, a co-product generated by ethanol industry to prepare acetates, carbonates and isovalerates. Selected conditions are compared to conventional routes to quantify their ecoefficiency and to check their potential development for the preparation of new biosolvents. In another step, we have calculated the volatile organic compound amount emitted during the production of a new cosmetic formulation using the fusel oil derivatives. This complete but simple example shows how to identify a real competitive alternative to the usual production chains.
Silylene-Bridged Tetranuclear Palladium Cluster as a Catalyst for Hydrogenation of Alkenes and Alkynes
Yanagisawa, Chikako,Yamazoe, Seiji,Sunada, Yusuke
, p. 169 - 173 (2020/10/29)
A planar tetranuclear palladium cluster was obtained from the reaction of a cyclotetrasilane with [Pd(CNtBu)2]3. Single-crystal X-ray diffraction analysis and DFT calculations revealed that the tetranuclear framework of the cluster was supported effectively by the bridging organosilylene ligand. Although [Pd(CNtBu)2]3 as well as mononuclear palladium bis(silyl) complex, cis-Pd(SiMePh2)2(CNtBu)2, do not act as the effective catalyst, the planar tetranuclear palladium cluster acts as an efficient catalyst for the hydrogenation of alkenes and alkynes including sterically hindered tri- and tetra-substituted alkenes.
Environmentally responsible, safe, and chemoselective catalytic hydrogenation of olefins: ppm level Pd catalysis in recyclable water at room temperature
Gallou, Fabrice,Gao, Eugene S.,Lipshutz, Bruce H.,Takale, Balaram S.,Thakore, Ruchita R.
supporting information, p. 6055 - 6061 (2020/10/14)
Textbook catalytic hydrogenations are typically presented as reactions done in organic solvents and oftentimes under varying pressures of hydrogen using specialized equipment. Catalysts new and old are all used under similar conditions that no longer reflect the times. By definition, such reactions are both environmentally irresponsible and dangerous, especially at industrial scales. We now report on a general method for chemoselective and safe hydrogenation of olefins in water using ppm loadings of palladium from commercially available, inexpensive, and recyclable Pd/C, together with hydrogen gas utilized at 1 atmosphere. A variety of alkenes is amenable to reduction, including terminal, highly substituted internal, and variously conjugated arrays. In most cases, only 500 ppm of heterogeneous Pd/C is sufficient, enabled by micellar catalysis used in recyclable water at room temperature. Comparison with several newly introduced catalysts featuring base metals illustrates the superiority of chemistry in water.
