5462-71-5Relevant academic research and scientific papers
Visible-light photoredox-catalyzed selective carboxylation of C(sp3)?F bonds with CO2
Bo, Zhi-Yu,Chen, Lin,Gao, Tian-Yu,Jing, Ke,Lan, Yu,Liu, Shi-Han,Luo, Shu-Ping,Yan, Si-Shun,Yu, Bo,Yu, Da-Gang
supporting information, p. 3099 - 3113 (2021/11/16)
It is highly attractive and challenging to utilize carbon dioxide (CO2), because of its inertness, as a nontoxic and sustainable C1 source in the synthesis of valuable compounds. Here, we report a novel selective carboxylation of C(sp3)?F bonds with CO2 via visible-light photoredox catalysis. A variety of mono-, di-, and trifluoroalkylarenes as well as α,α-difluorocarboxylic esters and amides undergo such reactions to give important aryl acetic acids and α-fluorocarboxylic acids, including several drugs and analogs, under mild conditions. Notably, mechanistic studies and DFT calculations demonstrate the dual role of CO2 as an electron carrier and electrophile during this transformation. The fluorinated substrates would undergo single-electron reduction by electron-rich CO2 radical anions, which are generated in situ from CO2 via sequential hydride-transfer reduction and hydrogen-atom-transfer processes. We anticipate our finding to be a starting point for more challenging CO2 utilization with inert substrates, including lignin and other biomass.
Desulfonylative Electrocarboxylation with Carbon Dioxide
Zhong, Jun-Song,Yang, Zi-Xin,Ding, Cheng-Lin,Huang, Ya-Feng,Zhao, Yi,Yan, Hong,Ye, Ke-Yin
supporting information, p. 16162 - 16170 (2021/09/02)
Electrocarboxylation of organic halides is one of the most investigated electrochemical approaches for converting thermodynamically inert carbon dioxide (CO2) into value-added carboxylic acids. By converting organic halides into their sulfone derivatives, we have developed a highly efficient electrochemical desulfonylative carboxylation protocol. Such a strategy takes advantage of CO2as the abundant C1 building block for the facile preparation of multifunctionalized carboxylic acids, including the nonsteroidal anti-inflammatory drug ibuprofen, under mild reaction conditions.
Relative activity of metal cathodes towards electroorganic coupling of CO2 with benzylic halides
Engelhardt, Helen,Klinkova, Anna,Medvedev, Jury J.,Medvedeva, Xenia V.
, (2021/05/26)
Electrochemical reduction of benzylic halides represents a convenient route to generating carbanions for their subsequent coupling with CO2 to obtain various carboxylic acids. Despite the industrial prospects of this synthetic process, it still lacks systematic studies of the efficient catalysts and reaction media design. In this work, we performed a detailed analysis of the catalytic activity of a series of different metal electrodes towards electroreduction of benzylic halides to corresponding radicals and carbanions using cyclic voltammetry. Specifically, we screened and summarized the performance of 12 bulk metal cathodes (Ag, Au, Cu, Pd, Pt, Ni, Ti, Zn, Fe, Al, Sn, and Pb) and 3 carbon-based materials (glassy carbon, carbon cloth, and carbon paper) towards electrocarboxylation of eight different benzylic halides and compare it to direct CO2 reduction in acetonitrile. Extensive experimental studies along with a detailed analysis of the results allowed us to map specific electrochemical properties of different metal electrodes, i.e., the potential zones related to the one- and two-electron reduction of organic halides as well as the potential windows where the electrochemical activation of CO2 does not occur. The reported systematic analysis should facilitate the development of nanostructured electrodes based on group 10 and 11 transition metals to further optimize the efficiency of electrocarboxylation of halides bearing specific substituents and make this technology competitive to current synthetic methods for the synthesis of carboxylic acids.
Pd(OH)2/C, a Practical and Efficient Catalyst for the Carboxylation of Benzylic Bromides with Carbon Monoxide
Wakuluk-Machado, Anne-Marie,Dewez, Damien F.,Baguia, Hajar,Imbratta, Miguel,Echeverria, Pierre-Georges,Evano, Gwilherm
, p. 713 - 723 (2020/02/04)
A simple, efficient, cheap, and broadly applicable system for the carboxylation of benzylic bromides with carbon monoxide and water is reported. Upon simple reaction with only 2.5 wt % of Pearlman's catalyst and 10 mol % of tetrabutylammonium bromide in tetrahydrofuran at 110 °C for 4 h, a range of benzylic bromides can be smoothly converted to the corresponding arylacetic acids in good to excellent yields after simple extraction and acid-base wash. The reaction was found to be broadly applicable, scalable, and could be successfully extended to the use of ex situ-generated carbon monoxide and applied to the synthesis of the nonsteroidal anti-inflammatory drug diclofenac.
Oxidation of Alkynyl Boronates to Carboxylic Acids, Esters, and Amides
Li, Chenchen,Li, Ruoling,Zhang, Bing,Zhao, Pei,Zhao, Wanxiang
supporting information, p. 10913 - 10917 (2020/05/25)
A general efficient protocol was developed for the synthesis of carboxylic acids, esters, and amides through oxidation of alkynyl boronates, generated directly from terminal alkynes. This protocol represents the first example of C(sp)?B bond oxidation. This approach displays a broad substrate scope, including aryl and alkyl alkynes, and exhibits excellent functional group tolerance. Water, primary and secondary alcohols, and amines are suitable nucleophiles for this transformation. Notably, amino acids and peptides can be used as nucleophiles, providing an efficient method for the synthesis and modification of peptides. The practicability of this methodology was further highlighted by the preparation of pharmaceutical molecules.
Method for converting benzyl borate compounds into phenylacetic acid and derivatives thereof by carbon dioxide
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Paragraph 0042-0043, (2020/03/06)
The invention discloses a method for converting benzyl borate compounds into phenylacetic acid and derivatives thereof by carbon dioxide. The method comprises the steps: dissolving the benzyl borate compounds and an alkali in an organic solvent in the absence of a metal catalyst, introducing carbon dioxide into the reaction system, carrying out a reaction at the temperature of 50-150 DEG C for 3-72 hours, and acidifying to obtain phenylacetic acid or the derivatives thereof. The method is a green, simple and efficient method for synthesizing phenylacetic acid and the derivatives thereof, greenhouse gas carbon dioxide is used as a carbon source in the reaction, no transition metal catalyst is used, and the method is environmentally friendly, economical and high in efficiency.
Preparation method of phenylacetic acid type compound
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Paragraph 0122; 0123; 0124; 0131-0133, (2019/02/21)
The invention discloses a preparation method of a phenylacetic acid type compound. The preparation method of the phenylacetic acid type compound I comprises the following steps that in a solvent and aCO gas phase system, a benzyl halide type compound II, pyridine-2-cobalt carboxylate, palladium acetate and alkaline neutralizers take carbonylation reaction to obtain the phenylacetic acid type compound I. A mixed catalytic system has a synergistic effect; the whole use quantity of catalysts is greatly reduced. When the mixed catalyst is used, a better catalytic effect can be achieved; the characteristics of easily obtaining the catalyst, avoiding the production safety risk of toxic three wastes and the like, reducing the reaction pressure, realizing mild reaction conditions, reducing the production risk, facilitating the production and the like are realized. The formulas are shown in description.
Preparation method of acid with different substituent groups
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Paragraph 0048-0052, (2019/10/23)
The invention discloses a preparation method of an acid with different substituent groups. A terminal alkyne is lithiated with n-butyllithium, and then reacts with isopropoxyboronic acid pinacol ester, hydrogen chloride is added to achieve quenching, then the obtained reaction product is oxidized by an oxidizing agent, and the oxidized reaction product is separated and purified to obtain the acid.The method of the invention has the advantages of simplicity in operation, one-pot process preparation, no metal catalysis, nontoxic reagents, greenness, environmental friendliness and high atomic utilization rate, and provides a novel and quick way for preparing the acid with different substituent groups; and the obtained acid is an important fine chemical product, and can be widely used in fields of medicines, pesticides, spices and other industries.
Visible-Light-Driven External-Reductant-Free Cross-Electrophile Couplings of Tetraalkyl Ammonium Salts
Liao, Li-Li,Cao, Guang-Mei,Ye, Jian-Heng,Sun, Guo-Quan,Zhou, Wen-Jun,Gui, Yong-Yuan,Yan, Si-Shun,Shen, Guo,Yu, Da-Gang
supporting information, p. 17338 - 17342 (2019/01/04)
Cross-electrophile couplings between two electrophiles are powerful and economic methods to generate C-C bonds in the presence of stoichiometric external reductants. Herein, we report a novel strategy to realize the first external-reductant-free cross-electrophile coupling via visible-light photoredox catalysis. A variety of tetraalkyl ammonium salts, bearing primary, secondary, and tertiary C-N bonds, undergo selective couplings with aldehydes/ketone and CO2. Notably, the in situ generated byproduct, trimethylamine, is efficiently utilized as the electron donor. Moreover, this protocol exhibits mild reaction conditions, low catalyst loading, broad substrate scope, good functional group tolerance, and facile scalability. Mechanistic studies indicate that benzyl radicals and anions might be generated as the key intermediates via photocatalysis, providing a new direction for cross-electrophile couplings.
Electrochemical direct carboxylation of benzyl alcohols having an electron-withdrawing group on the phenyl ring: One-step formation of phenylacetic acids from benzyl alcohols under mild conditions
Senboku, Hisanori,Yoneda, Kenji,Hara, Shoji
, p. 6772 - 6776 (2016/01/30)
Electrochemical direct carboxylation of benzyl alcohols having an electron-withdrawing group on the phenyl ring was successfully carried out by constant current electrolysis using an undivided cell equipped with a platinum plate cathode and a magnesium rod anode in DMF in the presence of carbon dioxide. Reductive cleavage of the C-O bond followed by fixation of carbon dioxide efficiently took place at the benzylic position without any additive to give the corresponding phenylacetic acids in good yields in one step under neutral and mild conditions.
