1646-27-1Relevant academic research and scientific papers
Synthesis of 1-benzofuran-2-carboxylates by reaction of 1-benzofuran with halomethanes and alcohols in the presence of iron compounds
Khusnutdinov,Baiguzina,Mukminov
, p. 437 - 441 (2011)
Alkyl 1-benzofuran-2-carboxylates were obtained in quantitative yield by reaction of 1-benzofuran with halomethanes and alcohols in the presence of iron-containing catalysts both in the presence and in the absence of radical initiators.
Cobalt Nanoparticles-Catalyzed Widely Applicable Successive C?C Bond Cleavage in Alcohols to Access Esters
Dai, Wen,Gao, Shuang,Li, Guosong,Luo, Huihui,Lv, Ying,Shang, Sensen,Wang, Lianyue
supporting information, p. 19268 - 19274 (2020/08/26)
Selective cleavage and functionalization of C?C bonds have important applications in organic synthesis and biomass utilization. However, functionalization of C?C bonds by controlled cleavage remains difficult and challenging because they are inert. Herein, we describe an unprecedented efficient protocol for the breaking of successive C?C bonds in alcohols to form esters with one or multiple carbon atoms less using heterogeneous cobalt nanoparticles as catalyst with dioxygen as the oxidant. A wide range of alcohols including inactive long-chain alkyl aryl alcohols undergo smoothly successive cleavage of adjacent ?(C?C)n? bonds to afford the corresponding esters. The catalyst was used for seven times without any decrease in activity. Characterization and control experiments disclose that cobalt nanoparticles are responsible for the successive cleavage of C?C bonds to achieve excellent catalytic activity, while the presence of Co-Nx has just the opposite effect. Preliminary mechanistic studies reveal that a tandem sequence reaction is involved in this process.
Rhodium-Catalyzed Intermolecular Cyclopropanation of Benzofurans, Indoles, and Alkenes via Cyclopropene Ring Opening
Jeyaseelan, Rubaishan,Lautens, Mark,Ross, Rachel J.
supporting information, (2020/06/29)
The generation of metal carbenoids via ring opening of cyclopropenes by transition metals offers a simple entry into highly reactive intermediates. Herein, we describe a diastereoselective intermolecular rhodium-catalyzed cyclopropanation of heterocycles and alkenes using cyclopropenes as carbene precursors with a low loading of a commercially available rhodium catalyst. The reported method is scalable and could be performed with catalyst loadings as low as 0.2 mol %, with no impact to the reaction yield or selectivity.
Tandem Synthesis of 2-Carboxybenzofurans via Sequential Cu-Catalyzed C-O Coupling and Mo(CO)6-Mediated Carbonylation Reactions
Mo, Qinliang,Sun, Nan,Jin, Liqun,Hu, Baoxiang,Shen, Zhenlu,Hu, Xinquan
, p. 11490 - 11500 (2020/10/12)
A modular tandem synthesis of 2-carboxybenzofurans from 2-gem-dibromovinylphenols has been established based on a sequence of Cu-catalyzed intramolecular C-O coupling and Mo(CO)6-mediated intermolecular carbonylation reactions. This protocol allowed one-step access to a broad variety of functionalized benzofuran-2-carboxylic acids, esters, and amides in good to excellent yields under Pd- and CO gas-free conditions.
Methoxylation of Acyl Fluorides with Tris(2,4,6-trimethoxyphenyl)phosphine via C-OMe Bond Cleavage under Metal-Free Conditions
Ishida, Takumi,Nishihara, Yasushi,Wang, Xiu,Wang, Zhenhua
, p. 7526 - 7533 (2020/06/27)
Acyl fluorides are subjected to methoxylation with tris(2,4,6-trimethoxyphenyl)phosphine (TMPP) to afford the corresponding methyl esters in good to excellent yields. This transformation is featured by C(sp2)-OMe bond cleavage under metal-free conditions. Unprecedented utilization of TMPP as a methoxylating agent realized the installation of an OMe group into the desired products.
Direct Alkoxycarbonylation of Heteroarenes via Cu-Mediated Trichloromethylation and in Situ Alcoholysis
Jiang, Huanfeng,Jiang, Kai,Li, Yingwei,Luo, Wenkun,Yin, Biaolin
supporting information, (2020/03/04)
We report an efficient approach for direct alkoxycarbonylation of furans as well as other heteroarenes via a one-step copper-mediated reaction of three components (i.e., heteroarene, alcohol, and CHCl3). The copper additive was confirmed to simultaneously promote the reaction in three pathways: oxidant cracking, single electron transfer, and alcoholysis. By means of this protocol, various functionalized furancarboxylates and other heteroarenecarboxylates were facilely obtained in moderate to good yields.
Visible Light-Promoted Photocatalytic C-5 Carboxylation of 8-Aminoquinoline Amides and Sulfonamides via a Single Electron Transfer Pathway
Sen, Chiranjit,Sahoo, Tapan,Singh, Harshvardhan,Suresh, Eringathodi,Ghosh, Subhash Chandra
, p. 9869 - 9896 (2019/08/20)
An efficient photocatalytic method was developed for the remote C5-H bond carboxylation of 8-aminoquinoline amide and sulfonamide derivatives. This methodology uses in situ generated ?CBr3 radical as a carboxylation agent with alcohol and is further extended to a variety of arenes and heteroarenes to synthesize the desired carboxylated product in moderate-to-good yields. The reaction proceeding through a single electron transfer pathway was established by a control experiment, and a butylated hydroxytoluene-trapped aryl radical cation intermediate in high-resolution mass spectrometry was identified.
Amide pyridine derivative and application thereof
-
Paragraph 0076-0078, (2019/02/06)
The invention belongs to the technical field of medicine and relates to an amide pyridine derivative which is shown as a general formula I. The invention further relates to stereoisomer and pharmaceutically-acceptable salt, hydrate, solvate or prodrug of the amide pyridine derivative. The definitions of substituent groups of Ar, M, R and Py are given out in an instruction book. The invention further relates to a method for preparing the compound shown in the general formula I, pharmaceutical composition containing the compound and application of the compound and the pharmaceutical compositionin preparing medicine for treating and preventing superficial-layer fungal diseases and deep-layer fungal diseases.
Direct Carboxylation of Electron-Rich Heteroarenes Promoted by LiO-tBu with CsF and [18]Crown-6
Shigeno, Masanori,Hanasaka, Kazuya,Sasaki, Keita,Nozawa-Kumada, Kanako,Kondo, Yoshinori
supporting information, p. 3235 - 3239 (2019/02/13)
We herein demonstrate that the combination of LiO-tBu, CsF, and [18]crown-6 efficiently promotes the direct C?H carboxylation of electron-rich heteroarenes (benzothiophene, thiophene, benzofuran, and furan derivatives). A variety of functional groups, including methyl, methoxy, halo, cyano, amide, and keto moieties, are compatible with this system. The reaction proceeds via the formation of a tert-butyl carbonate species.
A biocatalytic method for the chemoselective aerobic oxidation of aldehydes to carboxylic acids
Knaus, Tanja,Tseliou, Vasilis,Humphreys, Luke D.,Scrutton, Nigel S.,Mutti, Francesco G.
, p. 3931 - 3943 (2018/09/11)
Herein, we present a study on the oxidation of aldehydes to carboxylic acids using three recombinant aldehyde dehydrogenases (ALDHs). The ALDHs were used in purified form with a nicotinamide oxidase (NOx), which recycles the catalytic NAD+ at the expense of dioxygen (air at atmospheric pressure). The reaction was studied also with lyophilised whole cell as well as resting cell biocatalysts for more convenient practical application. The optimised biocatalytic oxidation runs in phosphate buffer at pH 8.5 and at 40 °C. From a set of sixty-one aliphatic, aryl-Aliphatic, benzylic, hetero-Aromatic and bicyclic aldehydes, fifty were converted with elevated yield (up to >99%). The exceptions were a few ortho-substituted benzaldehydes, bicyclic heteroaromatic aldehydes and 2-phenylpropanal. In all cases, the expected carboxylic acid was shown to be the only product (>99% chemoselectivity). Other oxidisable functionalities within the same molecule (e.g. hydroxyl, alkene, and heteroaromatic nitrogen or sulphur atoms) remained untouched. The reaction was scaled for the oxidation of 5-(hydroxymethyl)furfural (2 g), a bio-based starting material, to afford 5-(hydroxymethyl)furoic acid in 61% isolated yield. The new biocatalytic method avoids the use of toxic or unsafe oxidants, strong acids or bases, or undesired solvents. It shows applicability across a wide range of substrates, and retains perfect chemoselectivity. Alternative oxidisable groups were not converted, and other classical side-reactions (e.g. halogenation of unsaturated functionalities, Dakin-Type oxidation) did not occur. In comparison to other established enzymatic methods such as the use of oxidases (where the concomitant oxidation of alcohols and aldehydes is common), ALDHs offer greatly improved selectivity.
