1732-08-7Relevant articles and documents
Efficient and sustainable transformation of gamma-valerolactone into nylon monomers
Yang, Yong,Wei, Xurui,Zeng, Fanxin,Deng, Li
, p. 691 - 694 (2016)
Herein, we reported the facile synthesis of dicarboxylic esters from biomass derived gamma-valerolactone (GVL) aiming for nylon monomer preparation via a novel synthetic route which improved the efficiency and overcame the need for toxic carbon monoxide for the synthesis of dicarboxylic esters from GVL.
First total syntheses of the pro-resolving lipid mediators 7(S),13(R),20(S)-Resolvin T1 and 7(S),13(R)-Resolvin T4
Rodriguez, Ana R.,Spur, Bernd W.
, (2020)
The first total syntheses of the pro-resolving lipid mediators 7(S),13(R),20(S)-Resolvin T1 [7(S),13(R),20(S)-RvT1] and 7(S),13(R)-Resolvin T4 [7(S),13(R)-RvT4], derived from n-3 docosapentaenoic acid (n-3 DPA), are described. 7(S),13(R),20(S)-RvT1 was prepared from 7(S),13(R)-RvT4 via an enzymatic lipoxidase reaction. 7(S),13(R)-RvT4 was obtained by total synthesis where the chiral centers at C7 and C13 where introduced by a Noyori transfer hydrogenation and a chiral pool strategy respectively. Wittig reactions, Sonogashira coupling and Boland Zn(Cu/Ag) reduction were the key steps in the synthesis.
FLOW CHEMISTRY SYNTHESIS OF ISOCYANATES
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Paragraph 0175; 0186-0187; 0217-0219, (2021/06/22)
The disclosure provides, inter alia, safe and environmentally-friendly methods, such as flow chemistry, to synthesize isocyanates, such as methylene diphenyl diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and tetramethylxylene diisocyanate.
Efficient Palladium-Catalyzed Carbonylation of 1,3-Dienes: Selective Synthesis of Adipates and Other Aliphatic Diesters
Yang, Ji,Liu, Jiawang,Ge, Yao,Huang, Weiheng,Ferretti, Francesco,Neumann, Helfried,Jiao, Haijun,Franke, Robert,Jackstell, Ralf,Beller, Matthias
supporting information, p. 9527 - 9533 (2021/03/08)
The dicarbonylation of 1,3-butadiene to adipic acid derivatives offers the potential for a more cost-efficient and environmentally benign industrial process. However, the complex reaction network of regioisomeric carbonylation and isomerization pathways, make a selective and direct transformation particularly difficult. Here, we report surprising solvent effects on this palladium-catalysed process in the presence of 1,2-bis-di-tert-butylphosphin-oxylene (dtbpx) ligands, which allow adipate diester formation from 1,3-butadiene, carbon monoxide, and methanol with 97 % selectivity and 100 % atom-economy under scalable conditions. Under optimal conditions a variety of di- and triesters from 1,2- and 1,3-dienes can be obtained in good to excellent yields.
Enantioselective Palladium-Catalyzed Decarboxylative Allylation of β-Keto Esters Assisted by a Thiourea
Qian, Hua,Gu, Guoxian,Zhou, Qinghai,Lu, Jiaxiang,Chung, Lung Wa,Zhang, Xumu
supporting information, p. 51 - 56 (2017/10/06)
Enantioselective intramolecular decarboxylative allylation of β-keto esters catalyzed by a palladium bis(phosphine)-thiourea complex is reported. This procedure is not only effective for β-keto esters, but also effective for β-keto amides. An intermolecular variant of the asymmetric decarboxylative allylation is also established. DFT calculations indicate that an outer-sphere mechanism is viable for the decarboxylative allylation of β-keto esters.
A Selective and Functional Group-Tolerant Ruthenium-Catalyzed Olefin Metathesis/Transfer Hydrogenation Tandem Sequence Using Formic Acid as Hydrogen Source
Zieliński, Grzegorz K.,Majtczak, Jaros?awa,Gutowski, Maciej,Grela, Karol
, p. 2542 - 2553 (2018/03/09)
A ruthenium-catalyzed transfer hydrogenation of olefins utilizing formic acid as a hydrogen donor is described. The application of commercially available alkylidene ruthenium complexes opens access to attractive C(sp3)-C(sp3) bond formation in an olefin metathesis/transfer hydrogenation sequence under tandem catalysis conditions. High chemoselectivity of the developed methodology provides a remarkable synthetic tool for the reduction of various functionalized alkenes under mild reaction conditions. The developed methodology is applied for the formal synthesis of the drugs pentoxyverine and bencyclane.
Synthetic method of 7-bromine-1-heptanol
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Paragraph 0012; 0013; 0014, (2018/04/01)
The invention provides a synthetic method of 7-bromine-1-heptanol. The synthetic method includes synthesizing dimethyl pimelate, 1, 7-heptandiol and 7-bromine-1-heptanol sequentially. The synthetic method has the advantages that the synthetic method is simple to operate and low in cost; through strict control of consumption and reaction time of hydrobromic acid, reaction conversion rate is increased, generation of dibromo-products is reduced greatly, and product purity, yield and productivity are improved; the content reaches more than 99%, and industrial production is facilitated.
Methylation of mono- and dicarboxylic acids with dimethyl carbonate catalyzed with binder-free zeolite NaY
Khusnutdinov,Shchadneva,Mayakova, Yu. Yu.,Konovalova, Yu. S.,Khazipova,Kutepov
, p. 163 - 168 (2017/04/24)
Synthesis of methyl mono- and dicarboxylates was developed consisting in treating the corresponding acids with dimethyl carbonate in the presence of a heterogenic catalyst, crystalline aluminosilicate whose mechanically strong granules to 90–95% were built of crystal aggregates of zeolite Y with modulus of about 5.0 in the Na-form. Optimum catalyst and reagents ratio and the reaction conditions were found for the preparation in high yields of methyl esters of mono- and dicarboxylic acids.
The synthesis of di-carboxylate esters using continuous flow vortex fluidics
Britton, Joshua,Dalziel, Stuart B.,Raston, Colin L.
, p. 2193 - 2200 (2016/04/19)
A vortex fluidic device (VFD) is effective in mediating the synthesis of di-esters at room temperature. Processing under ambient conditions allows for a simple and efficient synthesis, whilst operating under continuous flow addresses scalability. The rotational speed of the sample tube and the flow rate were critical variables during reaction optimization, and this relates to the behaviour of the fluid flow at a molecular level. Whilst at specific rotational speeds the tube imparts a vibrational response into the fluid flow, the flow rate dictates residence time and the ability to maintain high levels of shear stress. The combination of mechanically induced vibrations, rapid micromixing, high levels of shear stress and water evaporation results in yields up to 90% for 3.25 minutes or less residence time. These results are key for devising greener and more efficient processes both mediated by the VFD and other continuous flow platforms.
Metal/bromide autoxidation of triglycerides for the preparation of FAMES to improve the cold-flow characteristics of biodiesel
Phung, Peter,Rowlands, William N.,Thiyakesan, Appadurai,Benndorf, Paul,Masters, Anthony F.,Maschmeyer, Thomas
, p. 162 - 168 (2014/07/07)
Triglyceride autoxidation using a homogeneous Co/Mn/Zr/bromide catalyst in acetic acid (93%) of low grade tallow, canola oil or soy bean oil in a batch reactor at 150 °C for 2 h, produced lower molecular weight products relative to the fatty acids of the starting triglycerides. For the autoxidation of tallow the main products after esterification were monoesters Me(CH 2)mC(O)OMe (m = 5-12) and diesters MeOC(O)(CH 2)nC(O)OMe, (n = 7-12). Oxidation of the saturated fatty acids in triglycerides was confirmed and modelled using methyl palmitate. Post-treatment esterification of tallow autoxidation products to produce biodiesel (BD) esters resulted in improved cold temperature properties by a mean of 13.0 °C, i.e. a mean cloud point (CP) 1.0 °C (cf. unmodified tallow biodiesel: CP 14 °C).
