3073-92-5Relevant academic research and scientific papers
Chemoselective Hydrogenation of Olefins Using a Nanostructured Nickel Catalyst
Klarner, Mara,Bieger, Sandra,Drechsler, Markus,Kempe, Rhett
supporting information, p. 2157 - 2161 (2021/05/21)
The selective hydrogenation of functionalized olefins is of great importance in the chemical and pharmaceutical industry. Here, we report on a nanostructured nickel catalyst that enables the selective hydrogenation of purely aliphatic and functionalized olefins under mild conditions. The earth-abundant metal catalyst allows the selective hydrogenation of sterically protected olefins and further tolerates functional groups such as carbonyls, esters, ethers and nitriles. The characterization of our catalyst revealed the formation of surface oxidized metallic nickel nanoparticles stabilized by a N-doped carbon layer on the active carbon support.
The Guanidine-Promoted Direct Synthesis of Open-Chained Carbonates
Shang, Yuhan,Zheng, Mai,Zhang, Haibo,Zhou, Xiaohai
, p. 933 - 938 (2019/09/30)
In order to reduce CO2 accumulation in the atmosphere, chemical fixation methodologies were developed and proved to be promising. In general, CO2 was turned into cyclic carbonates by cycloaddition with epoxides. However, the cyclic carbonates need to be converted into open-chained carbonates by transesterification for industrial usage, which results in wasted energy and materials. Herein, we report a process catalyzed by tetramethylguanidine (TMG) to afford linear carbonates directly. This process is greener and shows potential for industrial applications.
Synthesis of Bis(phosphino)silyl Pincer-Supported Iron Hydrides for the Catalytic Hydrogenation of Alkenes
Murphy, Luke J.,Ferguson, Michael J.,McDonald, Robert,Lumsden, Michael D.,Turculet, Laura
, p. 4814 - 4826 (2018/12/11)
The synthesis and characterization of Fe pincer complexes supported by a bis(phosphino)silyl (PSiP) ligand are described. While four-coordinate species of the type (PSiP)FeX (X = halide) proved challenging to access, examples of five-coordinate (PSiP)Fe(II) and (PSiP)Fe(I) species were prepared and crystallographically characterized. In studying the reactivity of such (PSiP)Fe precursors, a variety of iron hydride species were observed and characterized, and interconversion among such complexes facilitated by the coordination of N2 was noted. The structures and spectroscopic features of several such diamagnetic Fe(II) hydrides were elucidated, including that of a unique and highly stable η2-(Si-H)Fe(II) dihydride complex. A surrogate for a low coordinate (PSiP)FeH species in the form of its bis(dinitrogen) adduct was found to be an effective precatalyst for the direct hydrogenation of alkenes, including various mono- and disubstituted aliphatic alkenes, as well as a trisubstituted example. Esters and ethers were found to be well-tolerated by the catalyst, and alkyne hydrogenation was also demonstrated.
Continuous-Flow Reductive Alkylation: Synthesis of Bio-based Symmetrical and Disymmetrical Ethers
Bruniaux, Sophie,Luart, Denis,Len, Christophe
, p. 1849 - 1856 (2018/02/06)
For the first time, a reductive alkylation process in continuous flow has been elaborated for the conversion of bio-based alcohols and aldehydes into symmetrical and dissymmetrical high-value-added ethers for industrial companies. The developed method is an etherification associating liquid, solid and gas phases under green conditions (continuous flow, catalysis, bio-based starting materials).
The continuous acid-catalyzed dehydration of alcohols in supercritical fluids: A new approach to the cleaner synthesis of acetals, ketals, and ethers with high selectivity
Gray, William K.,Smail, Fiona R.,Hitzler, Martin G.,Ross, Stephen K.,Poliakoff, Martyn
, p. 10711 - 10718 (2007/10/03)
We report a new continuous method for forming ethers, acetals and ketals using solid acid catalysts, DELOXAN ASP or AMBERLYST 15, and supercritical fluid solvents. In the case of ether formation, we observe a high selectivity for linear alkyl ethers with little rearrangement to give branched ethers. Such rearrangement is common in conventional syntheses. Our approach is effective for a range of n-alcohols up to n-octanol and also for the secondary alcohol 2-propanol. In the reaction of phenol with an alkylating agent, the continuous reaction can be tuned to give preferential O- or C- alkylation with up to 49% O-alkylation with supercritical propene. We also investigate the synthesis of a range of cyclic ethers and show an improved method for the synthesis of THF from 1,4-butandiol under very mild conditions.
Hydrolysis and Alcoholysis of Esters of o-Nitrobenzenesulfonic Acid
Sendega,Makitra,Pirig
, p. 1438 - 1446 (2007/10/03)
The rate of solvolysis of esters of o-nitrobenzenesulfonic acid with water and C1-C4 alcohols is satisfactorily described by two-parametric Hammett-Taft equation with predominating effect of the electronic factor σ*. The effect of the structure of the hydrocarbon rest in the sulfonic ester group does not fit to this relationship.
CATALYTIC HYDROGENOLYSIS OF CYCLOPROPANES: METAL INSERTION INTO A SATURATED CARBON-CARBON BOND AS THE KEY STEP
Bessard, Ives,Schlosser, Manfred
, p. 1231 - 1238 (2007/10/02)
Hydrogenolytic ring cleavage of gem-difluorocyclopropanes occurs exclusively at the carbon-carbon bond opposite to the halogen-bearing center and affords mainly gem-difluoroalkanes.The intermediacy of catalyst/cyclopropane derived adducts (e.g., palladocyclobutanes or 1,3-dipalladiopropanes) is postulated in order to rationalize the formation of monofluorinated and halogen-free by-products and, in addition, to explain specific substituent effects on the reaction rates.
Organomagnesium Inner Complexes, Part I. Bis(dialkylaminoalkyl)- and Bis(alkoxybutyl)magnesium Compounds
Angermund, Klaus,Bogdanovic, Borislav,Koppetsch, Gudrun,Krueger, Carl,Mynott, Richard,et al.
, p. 455 - 466 (2007/10/02)
A series of magnesium inner complexes has been prepared by reacting MgH2 (prepared by homogeneous catalysis) with dialkylallyl- and -3-butenylamines and -3-butenylethers in the presence of catalytic amounts of ZrCl4.The monomeric nature of bis(4-methoxybutyl)magnesium has been confirmed by X-ray diffraction.The analogous syntheses of bis(3-alkoxypropyl)magnesium compounds failed: cleavage of the allyl ether with elimination of propene occurred.This cleavage reaction is accelerated by catalytic amounts of NiCl2 or ZrCl4. - Keywords: Magnesium, Inner Complexes, Crystal Structure, X-Ray
