23832-27-1Relevant academic research and scientific papers
OXIDATIVE CLEAVAGE OF OLEFINS, EPOXIDES AND ALCOHOLS
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Page/Page column 23, (2019/02/06)
Provided is a process for producing a compound I comprising at least one functional group chosen in the group consisting of epoxy group, hydroxyl group and carbonyl group and by reacting a compound J comprising at least one functional group chosen in the group consisting of alkenyl group, epoxy group and hydroxyl group with an an oxidant in the presence of solid amphiphilic catalytic particles A and solid amphiphilic catalytic particles B.
Mechanistic Aspects of Hydrodeoxygenation of p-Methylguaiacol over Rh/Silica and Pt/Silica
Bouxin, Florent P.,Zhang, Xingguang,Kings, Iain N.,Lee, Adam F.,Simmons, Mark J. H.,Wilson, Karen,Jackson, S. David
, p. 1586 - 1589 (2018/09/25)
The mechanism of p-methylguaiacol (PMG) hydrodeoxygenation (HDO) has been examined over two Rh/silica catalysts and a Pt/silica catalyst at 300 °C and 4 barg hydrogen. Sequential conversion of PMG to 4-methylcatechol is followed by m- and p-cresol formation and finally toluene production, although direct conversion of PMG to p-cresol is favored over a commercial Rh/silica catalyst. Dehydroxylation and hydrogenation are shown to occur over metal functions, while demethylation and demethoxylation are favored over the fumed silica support. A mechanistic pathway for HDO of PMG is proposed.
Deactivation study of the hydrodeoxygenation of p-methylguaiacol over silica supported rhodium and platinum catalysts
Bouxin,Zhang,Kings,Lee,Simmons,Wilson,Jackson
, p. 29 - 37 (2017/04/13)
Hydrodeoxygenation of para-methylguaiacol using silica supported Rh or Pt catalysts was investigated using a fixed-bed reactor at 300?°C, under 4 barg hydrogen and a WHSV of 2.5?h?1. The activity, selectivity and deactivation of the catalysts were examined in relation to time on stream. Three catalysts were tested: 2.5% Rh/silica supplied by Johnson Matthey (JM), 2.5% Rh/silica and 1.55% Pt/silica both prepared in-house. The Rh/silica (JM) showed the best stability with steady-state reached after 6?h on stream and a constant activity over 3?days of reaction. In contrast the other two catalysts did not reach steady state within the timeframe of the tests, with continuous deactivation over the time on stream. Nevertheless higher coking was observed on the Rh/silica (JM) catalyst, while all three catalysts showed evidence of sintering. The Pt catalyst (A) showed higher selectivity for the production of 4-methylcatechol while the Rh catalysts were more selective toward the cresols. In all cases, complete hydrodeoxygenation of the methylguaiacol to methylcyclohexane was not observed.
Synergistic Interaction within Bifunctional Ruthenium Nanoparticle/SILP Catalysts for the Selective Hydrodeoxygenation of Phenols
Luska, Kylie L.,Migowski, Pedro,El Sayed, Sami,Leitner, Walter
supporting information, p. 15750 - 15755 (2016/01/28)
Ruthenium nanoparticles immobilized on acid-functionalized supported ionic liquid phases (Ru NPs@SILPs) act as efficient bifunctional catalysts in the hydrodeoxygenation of phenolic substrates under batch and continuous flow conditions. A synergistic interaction between the metal sites and acid groups within the bifunctional catalyst leads to enhanced catalytic activities for the overall transformation as compared to the individual steps catalyzed by the separate catalytic functionalities.
Carbon Dioxide as a Protecting Group: Highly Efficient and Selective Catalytic Access to Cyclic cis-Diol Scaffolds
Laserna, Victor,Fiorani, Giulia,Whiteoak, Christopher J.,Martin, Eddy,Escudero-Adán, Eduardo,Kleij, Arjan W.
supporting information, p. 10416 - 10419 (2016/02/18)
The efficient and highly selective formation of a wide range of (hetero)cyclic cis-diol scaffolds using aminotriphenolate-based metal catalysts is reported. The key intermediates are cyclic carbonates, which are obtained in high yield and with high levels of diastereo- and chemoselectivity from the parent oxirane precursors and carbon dioxide. Deprotection of the carbonate structures affords synthetically useful cis-diol scaffolds with different ring sizes that incorporate various functional groups. This atom-efficient method allows the simple construction of diol synthons using inexpensive and accessible precursors and green metal catalysts and showcases the use of CO2 as a temporary protecting group. Protective Carbon: Aminotriphenolate complexes of FeIII and AlIII are highly efficient and selective catalysts for the conversion of functional (multi)cyclic oxiranes into the corresponding cis carbonates. Basic hydrolysis of the latter provides a series of useful cyclic cis-diol scaffolds in high yield. In this process, CO2 acts as both a temporary protecting group and an oxygen donor.
A procedure for the preparation of Ti-Beta zeolites for catalytic epoxidation with hydrogen peroxide
Tang, Bo,Dai, Weili,Sun, Xiaoming,Guan, Naijia,Li, Landong,Hunger, Michael
, p. 2281 - 2291 (2014/04/17)
Ti-Beta zeolite has been successfully prepared via a reproducible and scalable two-step post-synthesis strategy, which consists of creating vacant T sites with associated silanol groups by dealumination of H-Beta and subsequent dry impregnation of the resulting Si-Beta with titanocene dichloride. The mechanism of Ti incorporation into the framework of Beta is investigated by diffuse reflectance infrared Fourier transform (DRIFT) and multinuclear solid-state nuclear magnetic resonance (SSNMR) spectroscopy. Characterization results obtained from diffuse reflectance ultraviolet-visible (UV-vis) and X-ray photoelectron spectroscopy (XPS) reveal that the majority of incorporated Ti species exist in the form of isolated tetrahedrally coordinated Ti(iv) in the zeolite framework while a minority exists in the form of isolated octahedrally coordinated Ti(vi) at framework or extra-framework positions. The obtained Ti-Beta zeolites are highly active and selective catalysts for the epoxidation of unsaturated ketones, e.g. 2-cyclohexen-1-one, with hydrogen peroxide as an oxidant. A quasilinear correlation between the epoxidation rate and the number of framework Ti(iv) species could be drawn evidencing that these Ti(iv) species are responsible for the epoxidation activity of the Ti-Beta zeolites under study. The impact of preparation parameters and reaction conditions on the catalytic performances of the Ti-Beta zeolites in the epoxidation of unsaturated organic compounds with hydrogen peroxide is discussed in detail. the Partner Organisations 2014.
Acid-catalyzed aldol-Meerwein-Ponndorf-Verley-etherification reactions - Access to defined configured quaternary stereogenic centers
Seifert, Andrea,Rohr, Kerstin,Mahrwald, Rainer
, p. 1137 - 1144 (2012/02/15)
A novel asymmetric aldol-reduction-etherification process of aliphatic enolizable aldehydes is described. The intermediately formed aldol adducts - β-hydroxyaldehydes - were reduced and transformed into the corresponding 1,3-diol ethers by external secondary alcohols at the same time. Thus, with the help of chiral secondary alcohols an access to optically active 1,3-diol ether is given. Furthermore, asymmetric cross-aldol-Meerwein-Ponndorf reactions of enolizable aldehydes can also be realized under these reaction conditions.
Selective hydroformylation-hydrogenation tandem reaction of isoprene to 3-methylpentanal
Behr, Arno,Reyer, Sebastian,Tenhumberg, Nils
experimental part, p. 11742 - 11747 (2012/01/04)
The hydroformylation of isoprene catalysed by rhodium phosphine complexes usually yields a broad mixture of the monoaldehydes, the isomeric methylpentenals, as well as the dialdehyde 3-methyl-1,6-hexandial. Under usual reaction conditions the products of a consecutive hydrogenation are only formed as minor by-products. Surprisingly we discovered now a selective auto-tandem reaction consisting of a hydroformylation and a hydrogenation step if a rhodium complex with the chelate ligand bis(diphenylphosphino)ethane is used as catalyst. If branched aromatic solvents like cumene are applied the conversion of isoprene is nearly quantitatively and the yield of the tandem product 3-methylpentanal amounts to 85%. The Royal Society of Chemistry 2011.
An expedient procedure for the oxidative cleavage of olefinic bonds with PhI(OAc)2, NMO, and Catalytic OsO4
Nicolaou,Adsool, Vikrant A.,Hale, Christopher R. H.
supporting information; experimental part, p. 1552 - 1555 (2010/06/16)
(Figure Presented) PhI(OAc)2 In the presence of OsO4 (cat.) and 2,6-lutidine cleaves oleflnlc bonds to yield the corresponding carbonyl compounds, albeit, In some cases, with a-hydroxy ketones as byproduct. A more practical and clean protocol to effect oxidative cleavage of olefinic bonds involves NMO, OsO4 (cat.), 2,6-lutidine, and PhI(OAc) 2.
Methyl-substituted trans-1,2-cyclohexanediamines as new ligands for oxaliplatin-type complexes
Habala, Ladislav,Dworak, Claudia,Nazarov, Alexey A.,Hartinger, Christian G.,Abramkin, Sergey A.,Arion, Vladimir B.,Lindner, Wolfgang,Galanski, Markus,Keppler, Bernhard K.
, p. 137 - 146 (2008/09/17)
Three different pathways for the synthesis of substituted trans-(±)-1,2-cyclohexanediamines as new ligands for oxaliplatin-type compounds are presented. The different synthetic routes lead (i) by the synthesis of the compound via ortho-bromination of a su
