598-78-7Relevant articles and documents
Promotive effects in α-monochloropropionic acid catalytic synthesis with propionic anhydride
Xue, Jianwei,Qi, Beibei,Wen, Xiaoguang,Wang, Yingying,Lv, Zhiping,Li, Fuxiang
, p. 481 - 485 (2014)
Selective α-chlorination of propionic acid to synthesize α-monochloropropionic acid was investigated in a laboratory-scale at 130 °C at atmospheric total pressure and in the presence of propionic anhydride as catalyst. Sulfuric acid and common Lewis acid were selected as promotive catalysts considering that the acid-catalyzed enolization is the rate determining step in the chlorination reaction of this experiment, also the reaction selectivity and activity were discussed in the presence of promotive catalysts. The studies revealed that the ferric chloride and sulfuric acid all have prominent promotive effects. Typically the amount of α- monochloropropionic acid can reach 96.14 % when 0.07 g of ferric chloride was added. Furthermore, our results demonstrated that the reaction selectivity and activity were dramatically enhanced after introducing Lewis acid as promotive catalysts.
Highly efficient oxidation of alcohols to carboxylic acids using a polyoxometalate-supported chromium(iii) catalyst and CO2
Han, Sheng,Wang, Ying,Wei, Yongge,Wu, Zhikang,Yu, Han
, p. 3150 - 3154 (2020/06/19)
Direct catalytic oxidation of alcohols to carboxylic acids is very attractive, but economical catalysis systems have not yet been well established. Here, we show that a pure inorganic ligand-supported chromium compound, (NH4)3[CrMo6O18(OH)6] (simplified as CrMo6), could be used to effectively promote this type of reaction in the presence of CO2. In almost all cases, oxidation of various alcohols (aromatic and aliphatic) could be achieved under mild conditions, and the corresponding carboxylic acids can be achieved in high yield. The chromium catalyst 1 can be reused several times with little loss of activity. Mechanism study and control reactions demonstrate that the acidification proceeds via the key oxidative immediate of aldehydes.
1,3,2-Diazaphospholenes Catalyze the Conjugate Reduction of Substituted Acrylic Acids
Reed, John H.,Cramer, Nicolai
, p. 4262 - 4266 (2020/07/13)
The potent nucleophilicity and remarkably low basicity of 1,3,2-diazaphospholenes (DAPs) is exploited in a catalytic, metal-free 1,4-reduction of free α,β-unsaturated carboxylic acids. Notably, the reduction occurs without a prior deprotonation of the carboxylic acid moiety and hence does not consume an additional hydride equivalent. This highlights the excellent nucleophilic character and low basicity of DAP-hydrides. Functional groups such as Cbz group or alkyl halides which can be problematic with classical transition-metal catalysts are well tolerated in the DAP-catalyzed process. Moreover, the transformation is characterized by a low catalyst loading, mild reaction conditions at ambient temperature as well as fast reaction times and high yields. The proof-of-principle for a catalytic enantioselective version is described.
A Straightforward Homologation of Carbon Dioxide with Magnesium Carbenoids en Route to α-Halocarboxylic Acids
Monticelli, Serena,Urban, Ernst,Langer, Thierry,Holzer, Wolfgang,Pace, Vittorio
supporting information, p. 1001 - 1006 (2019/01/30)
The homologation of carbon dioxide with stable, (enantiopure) magnesium carbenoids constitutes a valuable method for preparing α-halo acid derivatives. The tactic features a high level of chemocontrol, thus enabling the synthesis of variously functionalized analogues. The flexibility to generate magnesium carbenoids through sulfoxide-, halogen- or proton- Mg exchange accounts for the wide scope of the reaction. (Figure presented.).
Catalytic Bromination of Alkyl sp3C-H Bonds with KBr/Air under Visible Light
Zhao, Mengdi,Lu, Wenjun
supporting information, p. 5264 - 5267 (2018/09/12)
Alkyl sp3C-H bonds of cycloalkanes and functional branch/linear alkanes have been successfully brominated with KBr using air or O2 as an oxidant at room temperature to 40 °C. The reactions are carried out in the presence of catalytic NaNO2 in 37% HCl (aq)/solvent under visible light, combining aerobic oxidations and photochemical radical processes. For various alkane substrates, CF3CH2OH, CHCl3, or CH2Cl2 is employed as an organic solvent, respectively, to enhance the efficiency of bromination.
An Efficient Aerobic Oxidation Protocol of Aldehydes to Carboxylic Acids in Water Catalyzed by an Inorganic-Ligand-Supported Copper Catalyst
Yu, Han,Ru, Shi,Zhai, Yongyan,Dai, Guoyong,Han, Sheng,Wei, Yongge
, p. 1253 - 1257 (2018/02/16)
A method for the aerobic oxidation of aldehydes to carboxylic acids in water by using an inorganic-ligand-supported copper catalyst was developed. This method was performed with the use of atmospheric oxygen as the sole oxidant under extremely mild aqueous conditions, and furthermore, a wide range of aldehydes with various functional groups were tolerated. The copper catalyst could be recycled and used in successive reactions at least six times without any appreciable degradation in performance. This method is operationally simple and avoids the use of high-costing, toxic, air/moisture-sensitive, and commercially unavailable organic ligands. The generality of this method gives it potential to be used on the industrial scale.
Visible Light-Induced Oxidative Chlorination of Alkyl sp3 C-H Bonds with NaCl/Oxone at Room Temperature
Zhao, Mengdi,Lu, Wenjun
supporting information, p. 4560 - 4563 (2017/09/11)
A visible light-induced monochlorination of cyclohexane with sodium chloride (5:1) has been successfully accomplished to afford chlorocyclohexane in excellent yield by using Oxone as the oxidant in H2O/CF3CH2OH at room temperature. Other secondary and primary alkyl sp3 C-H bonds of cycloalkanes and functional branch/linear alkanes can also be chlorinated, respectively, under similar conditions. The selection of a suitable organic solvent is crucial in these efficient radical chlorinations of alkanes in two-phase solutions. It is studied further by the achievement of high chemoselectivity in the chlorination of the benzyl sp3 C-H bond or the aryl sp2 C-H bond of toluene.
Synthesis method of alpha-chloropropionyl chloride
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Paragraph 0013, (2017/08/30)
The invention discloses a synthesis method of alpha-chloropropionyl chloride. The synthesis method comprises the following steps: (1) adding propionic acid, an acyl chloride catalyst and solvent into a reactor, starting to stir, introducing chlorine gas to perform substitution reaction, and distilling to collect an alpha-chloropropionic acid fraction directly used for next step of reaction after the reaction is completed; and (2) adding the alpha-chloropropionic acid obtained in the previous step and a catalyst into the reactor, starting to stir, slowly heating, introducing phosgene to react, and performing reduced pressure distillation after the reaction is completed to obtain the alpha-chloropropionyl chloride. The preparation method disclosed by the invention has the advantages of simple operation, high yield, no wastewater production during aftertreatment, mild reaction conditions and the like; and the acyl chloride catalyst used in the chlorination reaction of the first step can be recycled.
Catalytic Cracking of Lactide and Poly(Lactic Acid) to Acrylic Acid at Low Temperatures
Terrade, Frédéric G.,van Krieken, Jan,Verkuijl, Bastiaan J. V.,Bouwman, Elisabeth
, p. 1904 - 1908 (2017/05/16)
Despite being a simple dehydration reaction, the industrially relevant conversion of lactic acid to acrylic acid is particularly challenging. For the first time, the catalytic cracking of lactide and poly(lactic acid) to acrylic acid under mild conditions is reported with up to 58 % yield. This transformation is catalyzed by strong acids in the presence of bromide or chloride salts and proceeds through simple SN2 and elimination reactions.
Ketone-catalyzed photochemical C(sp3)–H chlorination
Han, Lei,Xia, Ji-Bao,You, Lin,Chen, Chuo
, p. 3696 - 3701 (2017/06/13)
Photoexcited arylketones catalyze the direct chlorination of C(sp3)–H groups by N- chlorosuccinimide. Acetophenone is the most effective catalyst for functionalization of unactivated C–H groups while benzophenone provides better yields for benzylic C–H functionalization. Activation of both acetophenone and benzophenone can be achieved by irradiation with a household compact fluorescent lamp. This light-dependent reaction provides a better control of the reaction as compared to the traditional chlorination methods that proceed through a free radical chain propagation mechanism.
