91061-46-0Relevant academic research and scientific papers
Photocarboxylation of Benzylic C-H Bonds
Meng, Qing-Yuan,Schirmer, Tobias E.,Berger, Anna Lucia,Donabauer, Karsten,K?nig, Burkhard
supporting information, p. 11393 - 11397 (2019/08/20)
The carboxylation of sp3-hybridized C-H bonds with CO2 is a challenging transformation. Herein, we report a visible-light-mediated carboxylation of benzylic C-H bonds with CO2 into 2-arylpropionic acids under metal-free conditions. Photo-oxidized triisopropylsilanethiol was used as the hydrogen atom transfer catalyst to afford a benzylic radical that accepts an electron from the reduced form of 2,3,4,6-tetra(9H-carbazol-9-yl)-5-(1-phenylethyl)benzonitrile generated in situ. The resulting benzylic carbanion reacts with CO2 to generate the corresponding carboxylic acid after protonation. The reaction proceeded without the addition of any sacrificial electron donor, electron acceptor or stoichiometric additives. Moderate to good yields of the desired products were obtained in a broad substrate scope. Several drugs were successfully synthesized using the novel strategy.
Deracemizing α-Branched Carboxylic Acids by Catalytic Asymmetric Protonation of Bis-Silyl Ketene Acetals with Water or Methanol
Mandrelli, Francesca,Blond, Aurélie,James, Thomas,Kim, Hyejin,List, Benjamin
supporting information, p. 11479 - 11482 (2019/07/18)
We report a highly enantioselective catalytic protonation of bis-silyl ketene acetals. Our method delivers α-branched carboxylic acids, including nonsteroidal anti-inflammatory arylpropionic acids such as Ibuprofen, in high enantiomeric purity and high yields. The process can be incorporated in an overall deracemization of α-branched carboxylic acids, involving a double deprotonation and silylation followed by the catalytic asymmetric protonation.
Site-Selective, Remote sp3 C?H Carboxylation Enabled by the Merger of Photoredox and Nickel Catalysis
Sahoo, Basudev,Bellotti, Peter,Juliá-Hernández, Francisco,Meng, Qing-Yuan,Crespi, Stefano,K?nig, Burkhard,Martin, Ruben
supporting information, p. 9001 - 9005 (2019/06/24)
A photoinduced carboxylation of alkyl halides with CO2 at remote sp3 C?H sites enabled by the merger of photoredox and Ni catalysis is described. This protocol features a predictable reactivity and site selectivity that can be modulated by the ligand backbone. Preliminary studies reinforce a rationale based on a dynamic displacement of the catalyst throughout the alkyl side chain.
Regioselectivity inversion tuned by iron(iii) salts in palladium-catalyzed carbonylations
Huang, Zijun,Cheng, Yazhe,Chen, Xipeng,Wang, Hui-Fang,Du, Chen-Xia,Li, Yuehui
supporting information, p. 3967 - 3970 (2018/04/23)
Impactful regioselectivity control is crucial for cost-effective chemical synthesis. By using cheap and abundant iron(iii) salts, the hydroxycarbonylations of both aromatic and aliphatic alkenes were significantly enhanced in both reactivity and selectivity (iso/n or n/iso up to >99:1). Moreover, Pd-catalyzed carbonylation selectivity can be switched from branched to linear by using different Fe(iii) salts. In addition, similar results were obtained for the carbonylation of secondary alcohols.
A Ligand-Directed Catalytic Regioselective Hydrocarboxylation of Aryl Olefins with Pd and Formic Acid
Liu, Wei,Ren, Wenlong,Li, Jingfu,Shi, Yuan,Chang, Wenju,Shi, Yian
supporting information, p. 1748 - 1751 (2017/04/11)
An effective Pd-catalyzed hydrocarboxylation of aryl olefins with Ac2O and formic acid is described. A variety of 2- and 3-arylpropanoic acids can be regioselectively formed by the judicious choice of ligand without the use of toxic CO gas.
Enantioselective Decarboxylative Cyanation Employing Cooperative Photoredox Catalysis and Copper Catalysis
Wang, Dinghai,Zhu, Na,Chen, Pinhong,Lin, Zhenyang,Liu, Guosheng
supporting information, p. 15632 - 15635 (2017/11/14)
The merger of photoredox catalysis with asymmetric copper catalysis have been realized to convert achiral carboxylic acids into enantiomerically enriched alkyl nitriles. Under mild reaction conditions, the reaction exhibits broad substrate scope, high yields and high enantioselectivities. Furthermore, the reaction can be scaled up to synthesize key chiral intermediates to bioactive compounds.
Cp2TiCl2-Catalyzed Regioselective Hydrocarboxylation of Alkenes with CO2
Shao, Peng,Wang, Sheng,Chen, Chao,Xi, Chanjuan
supporting information, p. 2050 - 2053 (2016/06/01)
Cp2TiCl2-catalyzed regioselective hydrocarboxylation of alkenes with CO2 to give carboxylic acids in high yields has been developed in the presence of iPrMgCl. The reaction proceeds with a wide range of alkenes under mild conditions. Styrene and its derivatives can transform to α-aryl carboxylic acids, and aliphatic alkenes can transform to form alkanoic acids.
Concise Synthesis of 2-Arylpropanoic Acids and Study of Unprecedented Reduction of 3-Hydroxy-2-arylpropenoic Acid Ethyl Ester to 2-Arylpropenoic Acid Ethyl Ester by BH3·THF
Shahid Islam,Ahmad, Syarhabil,Attu, Mary Rose,Foerstering, F. Holger,Mahmun Hossain
, p. 1273 - 1286 (2015/09/22)
We have developed a concise method of synthesizing racemic arylpropanoic acids, which have been widely used as nonsteroidal anti-inflammatory drugs (NSAIDs). The synthesis involves only four steps from commercially available benzaldehyde. The synthesis incorporates an unprecedented reduction reaction, conversion of 3-hydroxy-2-arylpropenoic acid ethyl ester to 2-arylpropenoic acid ethyl ester by BH3·THF. The reduction reaction has been investigated and optimized.
DNA-PK INHIBITORS
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Paragraph 0234, (2013/11/05)
The present invention relates to compounds useful as inhibitors of DNA-PK. The invention also provides pharmaceutically acceptable compositions comprising said compounds and methods of using the compositions in the treatment of various disease, conditions, or disorders.
Iron-catalyzed, highly regioselective synthesis of α-aryl carboxylic acids from styrene derivatives and CO2
Greenhalgh, Mark D.,Thomas, Stephen P.
, p. 11900 - 11903 (2012/09/07)
The iron-catalyzed hydrocarboxylation of aryl alkenes has been developed using a highly active bench-stable iron(II) precatalyst to give α-aryl carboxylic acids in excellent yields and with near-perfect regioselectivity. Using just 1 mol % FeCl2, bis(imino)pyridine 6 (1 mol %), CO 2 (atmospheric pressure), and a hydride source (EtMgBr, 1.2 equiv), a range of sterically and electronically differentiated aryl alkenes were transformed to the corresponding α-aryl carboxylic acids (up to 96% isolated yield). The catalyst was found to be equally active with a loading of 0.1 mol %. Preliminary mechanistic investigations show that an iron-catalyzed hydrometalation is followed by transmetalation and reaction with the electrophile (CO2).
