Xi:Irritant;
108-83-8Relevant academic research and scientific papers
Microwave promoted regeneration of carbonyl compounds from oximes using silica supported chromium trioxide
Bendale, Pravin M.,Khadilkar, Bhushan M.
, p. 5867 - 5868 (1998)
Silica supported chromium trioxide was found to be an efficient reagent for the oxidative cleavage of oximes to the corresponding aldehydes and ketones in 'dry media', under microwave irradiation in a domestic microwave oven.
Greener synthesis of pristane by flow dehydrative hydrogenation of allylic alcohol using a packed-bed reactor charged by pd/c as a single catalyst
Fukuyama, Takahide,Furuta, Akihiro,Hirobe, Yuki,Hyodo, Mamoru,Kasakado, Takayoshi,Ryu, Ilhyong
, (2021/10/05)
Our previous work established a continuous-flow synthesis of pristane, which is a saturated branched alkane obtained from a Basking Shark. The dehydration of an allylic alcohol that is the key to a tetraene was carried out using a packed-bed reactor charged by an acid–silica catalyst (HO-SAS) and flow hydrogenation using molecular hydrogen via a Pd/C catalyst followed. The present work relies on the additional propensity of Pd/C to serve as an acid catalyst, which allows us to perform a flow synthesis of pristane from the aforementioned key allylic alcohol in the presence of molecular hydrogen using Pd/C as a single catalyst, which is applied to both dehydration and hydrogenation. The present one-column-two-reaction-flow system could eliminate the use of an acid catalyst such as HO-SAS and lead to a significant simplification of the production process.
Effect of metal modification of titania and hydrogen co-feeding on the reaction pathways and catalytic stability in the acetone aldol condensation
Quesada,Faba,Díaz, Eva,Ordó?ez, Salvador
, p. 133 - 144 (2019/08/01)
A stable performance of TiO2 catalysts for gas-phase acetone aldol condensation was observed when reduced metals were added (Pt or Ni, 1.5 wt%) and the reactions were conducted in presence of hydrogen. In both cases, the resulting metal-loaded catalysts are stable for 10 h, whereas continuous deactivation is observed for the parent TiO2 catalyst (573 K). Both the activation of the H2 molecule by metal nanoparticles and the change of the catalytic surface by metal insertion (in the case of Ni-loaded catalyst) enable suppressing oligomerization (by hindering enolates formation) and the strong adsorption of intermediates (by decreasing the concentration of high-strength acid-basic active sites), respectively. More interestingly, these metals allow to tune the selectivity of the reaction. Indeed, the Ni-loaded titania catalyst is highly selective for the synthesis of α,β-unsaturated ketones (selectivity to unsaturated C6 and C9 species >98%, at ～12% acetone conversion), whereas the Pt-loaded one is highly selective to the formation of saturated C6 and C9 ketones (MIBK and DIBK, with selectivities >95% at ～42% acetone conversion). The catalytic activity and stability of the two materials (Ni/TiO2 and Pt/TiO2) in both absence and presence of H2 are compared between them and with those of the parent TiO2. The results obtained by the reaction gas-phase analysis are supplemented through different solid characterization techniques (i.e., CO2-TPD and NH3-TPD, HRTEM, XPS, TPO, and DRIFTS).
Iron-catalyzed urea synthesis: Dehydrogenative coupling of methanol and amines
Lane, Elizabeth M.,Hazari, Nilay,Bernskoetter, Wesley H.
, p. 4003 - 4008 (2018/05/04)
Substituted ureas have numerous applications but their synthesis typically requires the use of highly toxic starting materials. Herein we describe the first base-metal catalyst for the selective synthesis of symmetric ureas via the dehydrogenative coupling of methanol with primary amines. Using a pincer supported iron catalyst, a range of ureas was generated with isolated yields of up to 80% (corresponding to a catalytic turnover of up to 160) and with H2 as the sole byproduct. Mechanistic studies indicate a stepwise pathway beginning with methanol dehydrogenation to give formaldehyde, which is trapped by amine to afford a formamide. The formamide is then dehydrogenated to produce a transient isocyanate, which reacts with another equivalent of amine to form a urea. These mechanistic insights enabled the development of an iron-catalyzed method for the synthesis of unsymmetric ureas from amides and amines.
METHOD OF FORMING DIBK
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Paragraph 0014; 0015; 0016; 0017; 0018; 0019; 0020-0025, (2017/06/24)
A method of forming diisobutyl ketone (DIBK) is provided, which includes: (i) simultaneously providing methyl isobutyl ketone (MIBK), acetone, and hydrogen to a front end of a continuous serial reactor, wherein the MIBK and the acetone is condensed by a condensation catalyst to form an intermediate product; and (ii) hydrogenating the intermediate product to form a product by a hydrogenation catalyst at a back end of the continuous serial reactor, wherein the product includes DIBK.
Sodium hypochlorite pentahydrate (NaOCl·5H2O) crystals; An effective re-oxidant for TEMPO oxidation
Okada, Tomohide,Asawa, Tomotake,Sugiyama, Yukihiro,Iwai, Toshiaki,Kirihara, Masayuki,Kimura, Yoshikazu
, p. 2818 - 2827 (2016/05/19)
The novel oxidant of sodium hypochlorite pentahydrate (NaOCl·5H2O), which is now available for industrial and laboratory use has several advantageous properties. The crystalline material has 44% of NaOCl, contains minimal sodium hydroxide and sodium chloride, and the aqueous solution indicates pH 11-12. Herein, NaOCl·5H2O crystals are examined for use as an oxidant for primary and secondary alcohols, with or without nitroxyl radicals, in the presence or absence of phase-transfer catalysts. The pentahydrate crystals alone (without nitroxyl radicals) demonstrate a powerful oxidizing ability, converting secondary alcohols to the corresponding ketones. In the presence of TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl) or 1-Me-AZADO (1-methyl-2-azaadamantane N-oxy radical), sterically hindered secondary alcohols are oxidized without pH adjustment. A proposed mechanism for the oxidation is discussed.
Synthesis of Acetone-Derived C6, C9, and C12Carbon Scaffolds for Chemical and Fuel Applications
Moore, Cameron M.,Jenkins, Rhodri W.,Janicke, Michael T.,Kubic, William L.,Polikarpov, Evgueni,Semelsberger, Troy A.,Sutton, Andrew D.
, p. 3382 - 3386 (2016/12/27)
A simple, inexpensive catalyst system (Amberlyst 15 and Ni/SiO2–Al2O3) is described for the upgrading of acetone to a range of chemicals and potential fuels. Stepwise hydrodeoxygenation of the produced ketones can yield branched alcohols, alkenes, and alkanes. An analysis of these products is provided, which demonstrates that this approach can provide a product profile of valuable bioproducts and potential biofuels.
METHOD FOR OXIDIZING ALCOHOLS
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Paragraph 0034-0036; 0037-0038, (2016/12/01)
Oxidation of alcohols to carbonyl compounds is one of important basic reactions in organic synthesis. The present invention provides an oxidation method of alcohols, which secures high productivity and safely and conveniently obtains a targeted substance with good selectivity at high yields. The oxidation method of alcohols oxidizes alcohols represented by general formula 1, thereby manufacturing carbonyl compounds derived from the alcohols, and uses sodium hypochlorite pentahydrate as an oxidizing agent in the presence or absence of a catalyst. (In general formula 1, R^1 represents an alkyl group, an aryl group or an aralkyl group, and R^2 represents an alkyl group, an aryl group, an aralkyl group or a hydrogen atom.)COPYRIGHT KIPO 2015
Ru-C-ZnO composite catalysts for the synthesis of methyl isobutyl ketone via single step gas phase acetone self-condensation
Bagabas, Abdulaziz A.,Mokhtar, Mohamed,Akhmedov, Vagif M.,Narasimharao, Katabathini,Basahel, Sulaiman N.,Al-Rabiah, Abdulrahman
, p. 1278 - 1288 (2014/07/21)
Ruthenium/activated charcoal (Ru-C) was modified by a solid-solid interaction method with synthesized nano-zinc oxide (n-ZnO). Three different ratios of Ru-C:n-ZnO (1:2, 1:1 and 3:2) were used to prepare Ru-C-ZnO composite catalysts. These were used in the gas-phase, one-step self-condensation of acetone to methyl isobutyl ketone (MIBK). The composite catalyst (1:1 ratio) contained 2.5 wt% Ru showed superior conversion of acetone and selectivity for MIBK. Furthermore, this catalyst showed good consistency for MIBK formation for 100 h without any deactivation. Characterization of the catalysts revealed that balanced hydrogenation and acid-base functional character is crucial to obtain high catalytic performance.
Kinetics and mechanism of oxidation of aliphatic secondary alcohols by benzyltrimethylammonium chlorobromate
Sharma, Pradeep K.
, p. 2702 - 2706 (2014/06/09)
Oxidation of several secondary alcohols by benzyltrimethylammonium chlorobromate (BTMACB) in aqueous acetic acid leads to the formation of corresponding ketones. The reaction is first order with respect to BTMACB and the alcohols. The reaction failed to induce the polymerization of acrylonitrile. There is no effect of tetrabutylammonium chloride on the reaction rate. The proposed reactive oxidizing species is chlorobromate ion. The oxidation of benzhydrol-α-d (PhCDOHPh) exhibited a substantial primary kinetic isotope effect (kH/kD = 5.61 at 298 K). The effect of solvent composition indicated that the rate increases with an increase in the polarity of the solvent. The reaction is susceptible to both the polar and steric effects of the substituents. A mechanism involving transfer of a hydride ion in the ratedetermining step has been proposed.
