589-55-9Relevant articles and documents
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Delepine,Horeau
, p. 40 (1937)
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Regioselective C-H hydroxylation of: N -alkanes using Shilov-type Pt catalysis in perfluorinated micro-emulsions
De Vos, Dirk E.,Janssen, Michiel
, p. 1264 - 1272 (2020/03/23)
Shilov-chemistry inspired catalysis has remained largely overlooked as a tool for establishing the remote hydroxylation of non-polar compounds, such as long linear alkanes, due to the need for an acidic aqueous solution. To circumvent the solubility issue, the concept of micellar catalysis is introduced, using PtII in perfluorinated micro-emulsions. Notably, the terminal C-H activation of n-heptane is demonstrated under an oxygen atmosphere using perfluorooctanoic acid (PFOA) as a surfactant, along with the intrinsic ability of PtII to convert the highly inert primary C-H bonds. Coordination of PtII to the carboxylate groups of PFOA proved to be particularly important for achieving maximum catalyst activity towards the hydrocarbon substrate solubilized inside the micelle interior. Based on these insights, optimization of the reaction parameters allowed a positional selectivity of 60% for 1-heptanol, among the C7 alcohols, to be achieved, using low catalyst and surfactant loadings under acid-free conditions.
Benzimidazole fragment containing Mn-complex catalyzed hydrosilylation of ketones and nitriles
Ganguli, Kasturi,Mandal, Adarsha,Sarkar, Bidisha,Kundu, Sabuj
, (2020/08/13)
The synthesis of a new bidentate (NN)–Mn(I) complex is reported and its catalytic activity towards the reduction of ketones and nitriles is studied. On comparing the reactivity of various other Mn(I) complexes supported by benzimidazole ligand, it was observed that the Mn(I) complexes bearing 6-methylpyridine and benzimidazole fragments exhibited the highest catalytic activity towards monohydrosilylation of ketones and dihydrosilylation of nitriles. Using this protocol, a wide range of ketones were selectively reduced to the corresponding silyl ethers. In case of unsaturated ketones, the chemoselective reduction of carbonyl group over olefinic bonds was observed. Additionally, selective dihydrosilylation of several nitriles were also achieved using this complex. Mechanistic investigations with radical scavengers suggested the involvement of radical species during the catalytic reaction. Stoichiometric reaction of the Mn(I) complex with phenylsilane revealed the formation of a new Mn(I) complex.
Single-phase catalysis for reductive etherification of diesel bioblendstocks
Conklin, Davis R.,Guo, Qianying,Hafenstine, Glenn R.,Huo, Xiangchen,Huq, Nabila A.,Unocic, Kinga A.,Vardon, Derek R.,Wiatrowski, Matthew R.
supporting information, p. 4463 - 4472 (2020/08/10)
Reductive etherification is a promising catalytic chemistry for coupling biomass derived alcohols and ketones to produce branched ethers that can be used as high cetane, low sooting blendstocks for diesel fuel applications. Previous catalyst materials examined for reductive etherification have typically been limited to binary physical mixtures of metal hydrogenation and acidic acetalization catalysts with limited thermal stability and industrial applicability. To address this, we developed a single-phase catalyst comprising Pd supported on acidic metal oxides with high catalytic activity, product selectivity, and regeneration stability. Batch reactor screening identified niobium phosphate (NbOPO4) as the most active acidic metal oxide catalyst support, which was downselected to synthesize single-phase catalysts by Pd loading. Several branched ethers with favourable fuel properties were synthesized to demonstrate broad catalyst applicability. The fresh Pd/NbOPO4 catalyst displayed a surface area of 130 m2 g-1, high acidity of 324 μmol g-1 and Pd dispersion of 7.8percent. The use of acidic metal oxide support allowed for elevated reaction temperatures with a mass selectivity to 4-butoxyheptane of 81percent at 190 °C and an apparent activation energy of 40 kJ mol-1. Continuous flow reactor testing demonstrated steady catalyst deactivation due to coke formation of 10 wtpercent after 117 h of time-on-stream. Four simulated catalyst regeneration cycles led to small changes in surface area and total acidity; however, a decrease in Pd site density from 18 to 8 μmol g-1, in combination with an apparent Pd nanoparticle size effect, caused an increase in the production rate of 4-butoxyheptane from 138 to 190 μmol gcat-1 min-1 with the regenerated catalyst. Lastly, technoeconomic analysis showed that higher H2 equivalents and lower weight hourly space velocity values can reduce ether catalytic production costs.