5337-72-4Relevant academic research and scientific papers
Selective hydrogenation of lignin-derived compounds under mild conditions
Chen, Lu,Van Muyden, Antoine P.,Cui, Xinjiang,Laurenczy, Gabor,Dyson, Paul J.
, p. 3069 - 3073 (2020/06/17)
A key challenge in the production of lignin-derived chemicals is to reduce the energy intensive processes used in their production. Here, we show that well-defined Rh nanoparticles dispersed in sub-micrometer size carbon hollow spheres, are able to hydrogenate lignin derived products under mild conditions (30 °C, 5 bar H2), in water. The optimum catalyst exhibits excellent selectivity and activity in the conversion of phenol to cyclohexanol and other related substrates including aryl ethers.
Iridium Clusters Encapsulated in Carbon Nanospheres as Nanocatalysts for Methylation of (Bio)Alcohols
Liu, Qiang,Xu, Guoqiang,Wang, Zhendong,Liu, Xiaoran,Wang, Xicheng,Dong, Linlin,Mu, Xindong,Liu, Huizhou
, p. 4748 - 4755 (2017/12/15)
C?H methylation is an attractive chemical transformation for C?C bonds construction in organic chemistry, yet efficient methylation of readily available (bio)alcohols in water using methanol as sustainable C1 feedstock is limited. Herein, iridium nanocatalysts encapsulated in yolk–shell-structured mesoporous carbon nanospheres (Ir@YSMCNs) were synthesized for this transformation. Monodispersed Ir clusters (ca. 1.0 nm) were encapsulated in situ and spatially isolated within YSMCNs by a silica-assisted sol–gel emulsion strategy. A selection of (bio)alcohols (19 examples) was selectively methylated in aqueous phase with good-to-high yields over the developed Ir@YSMCNs. The improved catalytic efficiencies in terms of activity and selectivity together with the good stability and recyclability were contributable to the ultrasmall Ir clusters with oxidation chemical state as a consequence of the confinement effect of YSMCNs with interconnected nanostructures.
Selective Catalytic Hydrogenation of Arenols by a Well-Defined Complex of Ruthenium and Phosphorus-Nitrogen PN3-Pincer Ligand Containing a Phenanthroline Backbone
Li, Huaifeng,Wang, Yuan,Lai, Zhiping,Huang, Kuo-Wei
, p. 4446 - 4450 (2017/07/24)
Selective catalytic hydrogenation of aromatic compounds is extremely challenging using transition-metal catalysts. Hydrogenation of arenols to substituted tetrahydronaphthols or cyclohexanols has been reported only with heterogeneous catalysts. Herein, we demonstrate the selective hydrogenation of arenols to the corresponding tetrahydronaphthols or cyclohexanols catalyzed by a phenanthroline-based PN3-ruthenium pincer catalyst.
Alcohol oxidation with H2O2 catalyzed by a cheap and promptly available imine based iron complex
Olivo, Giorgio,Giosia, Simone,Barbieri, Alessia,Lanzalunga, Osvaldo,Di Stefano, Stefano
supporting information, p. 10630 - 10635 (2016/11/21)
We previously reported that the iminopyridine iron(II) complex 1, easily and quantitatively obtainable in situ, can activate H2O2 to form a powerful oxidant, capable of aliphatic C-H bond hydroxylation. In the present study we expand the application of this catalyst to the oxidation of a series of alcohols to the corresponding carbonyl compounds. The oxidation of aliphatic alcohols proceeds smoothly, while that of benzylic alcohols is shown to be challenging. Some collected pieces of evidence suggest a preference of the oxidizing species for the aromatic ring instead for the alcoholic moiety. The decrease of the electron density in the aromatic ring shifts the oxidation from the aromatic towards the alcoholic moiety. Quite surprisingly, preferential oxidation of cyclohexanol versus benzylic alcohol was achieved, showing unprecedented selectivity.
Chemoselective Hydrogenation and Transfer Hydrogenation of Olefins and Carbonyls with the Cluster-Derived Ruthenium Nanocatalyst in Water
Indra, Arindam,Maity, Prasenjit,Bhaduri, Sumit,Lahiri, Goutam Kumar
, p. 322 - 330 (2013/03/13)
Ion pairing of [H3Ru4(CO)12]- with the quaternary ammonium groups of water-soluble poly(diallyldimethylammonium chloride) gives the precursor of a nanocatalyst for hydrogenation and transfer hydrogenation reactions in water. In hydrogenation reactions, "on water" effect is seen for substrates such as cyclohexanones, methyl pyruvate, acetophenone, and safflower oil. With these substrates, higher turnover numbers are obtained in water than in methanol. The cluster-derived catalyst shows unique chemoselectivity, which is not seen either in a catalyst prepared through ion pairing of [RuCl4]- with the quaternary ammonium groups of the same polymer or in commercial (5%) Ru/Al2O3. In contrast to Ru/Al2O3, the [RuCl4]--derived catalyst, or many other ruthenium-based catalytic systems, the cluster-derived catalyst is totally inert toward the hydrogenation of -NO2, -CN, and aromatic ring functionalities. In water, typical ketones and aldehydes could be reduced by using the cluster-derived catalyst and formate as the hydrogen donor. Industrially important cyano- and nitrobenzyl alcohols could thus be made from the corresponding aldehydes. High-resolution TEM data suggest that unique chemoselectivity is a result of highly crystalline ruthenium nanoparticles that consist mainly of Ru(111) crystal planes.
Efficient and Practical Arene Hydrogenation by Heterogeneous Catalysts under Mild Conditions
Maegawa, Tomohiro,Akashi, Akira,Yaguchi, Kiichiro,Iwasaki, Yohei,Shigetsura, Masahiro,Monguchi, Yasunari,Sajiki, Hironao
experimental part, p. 6953 - 6963 (2010/02/28)
An efficient and practical arene hydrogenation procedure based on the use of heterogeneous platinum group catalysts has been developed. Rh/C is the most effective catalyst for the hydrogenation of the aromatic ring, which can be conducted in iPrOH under neutral conditions and at ordinary to medium H 2 pressures (10 atm). A variety of arenes such as alkylbenzenes, benzoic acids, pyridines, furans, are hydrogenated to the corresponding cyclohexyl and heterocyclic compounds in good to excellet yields. The use of Ru/C, less expensive than Rh/C, affords an effective and practical method for the hydrogenation of arenes including phenols. Both catalysts can be reused several times after simple filtration without any significant loss of catalytic activity.
A new mixed P,S-bidentate ligand featuring a λ4- phosphinine anion and a phosphanyl sulfide group - Synthesis, x-ray crystal structures and catalytic properties of its chloro(cymene)ruthenium and allylpalladium complexes
Dochnahl, Maximilian,Doux, Marjolaine,Faillard, Emilie,Ricard, Louis,Le Floch, Pascal
, p. 125 - 134 (2007/10/03)
1,3,2-Diazaphosphinine (1) reacts successively with diphenylacetylene and diphenyl(1-propynyl)phosphane sulfide to afford the P,S-bidentate phosphinine 3. Reaction of nBuLi with 3 followed by complexation with [RuCl2(C 10H14)]2 gave two diastereoisomers 5a,b. Variable-temperature NMR spectroscopy and ONIOM DFT calculations were carried out to rationalize their formation. Complexes 5a,b were used as catalysts in hydrogen-transfer hydrogenation (TON up to 200). Reaction of MeLi with 3 followed by complexation with [PdCl2(η3-C 3H5)]2 yielded two diastereomers 7a,b, which were used as catalysts in the Suzuki-Miyaura cross-coupling reaction of aryl bromides with pinacolborane to yield the corresponding arylboronic esters (TON up to 799000). Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
Dichloromethane activation. Direct methylenation of ketones and aldehydes with CH2Cl2 promoted by Mg/TiCl4/THF
Yan, Tu-Hsin,Tsai, Chia-Chung,Chien, Ching-Ting,Cho, Chia-Ching,Huang, Pei-Chen
, p. 4961 - 4963 (2007/10/03)
(Chemical Equation Presented) This Mg-TiCl4-promoted CH 2-transfer reaction of CH2Cl2 represents an extremely simple, practical, and efficient methylenation of a variety of ketones and aldehydes, especially in enolizable or sterically hindered ketones such as 2,2-dimethylcyclohexanone, camphor, and fenchone.
Isosteric antiherpes peptide derivatives II
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, (2008/06/13)
Disclosed herein are peptidomimetic compounds of the formula A--B--D--CH2 CH{CH2 C(O)R1 }C(O)--NHCH{CR2 (R3)COOH}C(O)--E wherein A is a terminal group, for example an optionally substituted phenylalkanoyl, and B is a N-methyl amino acid residue; or A and B together form a saturated or unsaturated alkylaminocarbonyl; D is an amino acid residue; R1 is alkyl, cycloalkyl, a monosubstituted or a disubstituted amino; R2 is hydrogen and R3 is phenylalkyl, or R2 and R3 are joined to form a cycloalkyl; and E is a terminal unit, for example, an alkylamino or a monovalent amino acid radical such as NHCH(alkyl)C(O)OH. The derivatives are useful for treating herpes infections.
