93-97-0Relevant academic research and scientific papers
The effect of microwave irradiation on carbodiimide-mediated esterifications on solid support
Stadler, Alexander,Kappe, C.Oliver
, p. 3915 - 3920 (2001)
The esterification of a polymer-supported alcohol (PS Wang resin) with benzoic acid was investigated using microwave irradiation. Activation of the carboxylic acid was carried out using diisopropylcarbodiimide, either via the O-acylisourea or symmetrical anhydride protocols. In the microwave-assisted solid-phase coupling using the O-acylisourea method the main product of the reaction was 1-benzoyl-1,3-diisopropylurea, formed by rearrangement of the thermolabile isourea intermediate. On the other hand, significant rate enhancements were observed for the coupling of benzoic anhydride to Wang resin using microwave flash heating in 1-methyl-2-pyrrolidone as solvent. Reaction times were reduced from 2 to 3 days using conventional conditions, to 10 min by microwave dielectric heating.
Clay-supported liquid-liquid-solid phase transfer catalysis: Synthesis of benzoic anhydride
Yadav,Naik, Suguna S.
, p. 141 - 146 (2000)
Solid-supported phase transfer catalysed reactions typically involve polystyrene supports cross-linked with divinyl benzene. The use of commercially available clay as a support for the PTC reaction is attractive. This paper reports the preparation of benzoic anhydride from benzoyl chloride and sodium benzoate using clay-supported quaternary ammonium salts at 30°C. The selectivity to the product is 100%. The mechanistic and kinetic aspects are also reported. The clay-supported catalyst was found to be more active than polymer-supported catalysts.
Synthesis and in vitro evaluation of taxol oxetane ring D precursors
Kaspera, Rüdiger,Cape, Jonathan L.,Faraldos, Juan A.,Ketchum, Raymond E.B.,Croteau, Rodney B.
, p. 2017 - 2019 (2010)
A series of potential taxoid substrates was prepared in radiolabeled form to probe in vitro for the oxirane formation step and subsequent ring expansion step to the oxetane (ring D) presumably involved in the biosynthesis of the anticancer agent Taxol. None of the taxoid test substrates underwent transformation in cell-free systems from Taxus suggesting that these surrogates bore substitution patterns inappropriate for recognition or catalysis by the target enzymes, or that taxoid oxiranes and oxetanes arise by independent biosynthetic pathways.
Multifunctional amphiphilic carbonaceous microcapsules catalyze water/oil biphasic reactions
Tan, Hongyi,Zhang, Peng,Wang, Lei,Yang, Dang,Zhou, Kebin
, p. 11903 - 11905 (2011)
Multifunctional amphiphilic hollow carbonaceous spheres assembled into Pickering emulsions exhibit reversible pH-dependent phase-transfer behavior and can efficiently catalyze water/oil biphasic reactions, facilitating the recycling of the catalysts and separation of the products.
Generation of Oxyphosphonium Ions by Photoredox/Cobaloxime Catalysis for Scalable Amide and Peptide Synthesis in Batch and Continuous-Flow
Chen, Xiangyang,Houk, Kendall N.,Mo, Jia-Nan,Su, Junqi,Umanzor, Alexander,Zhang, Zheng,Zhao, Jiannan
supporting information, (2022/01/06)
Phosphine-mediated deoxygenative nucleophilic substitutions, such as the Mitsunobu reaction, are of great importance in organic synthesis. However, the conventional protocols require stoichiometric oxidants to trigger the formation of the oxyphosphonium i
Preparation method of symmetric aromatic anhydride compound
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Paragraph 0053-0054; 0061-0062, (2021/08/11)
The invention discloses a preparation method of a symmetric aromatic anhydride compound, the preparation method comprises the following steps: dissolving alpha-terpilenol and pyridine in a solvent, adding an aroyl chloride solution, and reacting for 8-16 hours to obtain the symmetric aromatic anhydride compound. The alpha-terpilenol and the aroyl chloride are used as raw materials, and the method has the advantages of being easy to operate, mild in reaction condition, high in safety, simple in technological process and post-treatment, low in cost, high in yield of part of products and the like, and is very beneficial to industrialization.
Rh(I)-Catalyzed Direct C6?H Arylation of 2-Pyridones with Aryl Carboxylic Acids
Fan, Qinghua,Pan, Yixiao,Walsh, Patrick J.,Xu, Jianbin,Xu, Lijin,Xu, Xin,Yu, Zexin,Zhao, Haoqiang
supporting information, p. 3995 - 4001 (2021/07/02)
A Rh(I)-catalyzed C6-selective C?H arylation of 2-pyridones with inexpensive, readily available, safe and structurally diverse aryl carboxylic acids with the aid of a pyridine directing group is developed. This decarbonylative arylation protocol features an easy-to-handle catalytic system, and is amenable to diversely substituted 2-pyridones and aryl carboxylic acids. It allows access to a wide range of C6-arylated 2-pyridones, including those that are difficult to prepare using conventional C?H arylation processes. The method tolerates various electron-neutral, electron-rich and electron-deficient functional groups, and affords the products in 41–91% yields. (Figure presented.).
METHOD FOR PRODUCING CARBOXYLIC ACID ANHYDRIDE OR SULFONIC ACID ANHYDRIDE
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Paragraph 0050-0051, (2021/02/25)
To provide a method for producing carboxylic acid anhydride or sulfonic acid anhydride in which carboxylic acid anhydride or sulfonic acid anhydride is produced in a simple or easy process using carboxylic acid or sulfonic acid as raw material, and using an industrially available raw material and in an efficient process in industrial practice.SOLUTION: Provided is a method for producing carboxylic acid anhydride or sulfonic acid anhydride, which is a method for producing an acid anhydride by reacting carboxylic acid or sulfonic acid and a halogenating agent, and in which a solvent containing a phosphoric acid ester such as the formula (1) is used. (R1, R2 and R3 are the same or non-identical alkyl group or fluorine-containing alkyl group having 1 to 10 carbon atoms, and at least one is fluorine-containing alkyl group.).SELECTED DRAWING: None
Size-Induced Inversion of Selectivity in the Acylation of 1,2-Diols
Mayr, Stefanie,Zipse, Hendrik
supporting information, p. 18084 - 18092 (2021/12/02)
Relative rates for the Lewis base-catalyzed acylation of aryl-substituted 1,2-diols with anhydrides differing in size have been determined by turnover-limited competition experiments and absolute kinetics measurements. Depending on the structure of the anhydride reagent, the secondary hydroxyl group of the 1,2-diol reacts faster than the primary one. This preference towards the secondary hydroxyl group is boosted in the second acylation step from the monoesters to the diester through size and additional steric effects. In absolute terms the first acylation step is found to be up to 35 times faster than the second one for the primary alcohols due to neighboring group effects.
Direct Access to α,β-Unsaturated Ketones via Rh/MgCl2-Mediated Acylation of Vinylsilanes
Chen, Zi-Yan,Deng, Xue-Zu,Song, Yang,Xue, Fei,Yamane, Motoki,Yue, Yan-Ni
, p. 12693 - 12704 (2021/09/28)
We report herein the facile and practical construction of α,β-unsaturated ketones via rhodium-catalyzed direct acylation of vinylsilanes with readily available and abundant carboxylic acids. This protocol features access to a diverse array of synthetically useful functionalities with moderate to excellent yields. More importantly, the late-stage functionalization of pharmaceuticals was also realized with synthetically useful yield.
