- Ag(I)-Catalyzed C-H Carboxylation of Thiophene Derivatives
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CO2utilization is an attractive aspect as it allows the direct conversion of CO2into valuable chemicals. In this regard, direct incorporation of CO2into the C-H bond of heteroaromatic compounds is important due to the ubiquitous structural motifs of the heteroaromatic carboxylic acids. Herein, we report the Ag-catalyzed C-H carboxylation of thiophene derivatives. This new catalytic system involving a phosphine ligand and lithiumtert-butoxide enables the direct carboxylation of thiophenes under mild reaction conditions. Experimental studies revealed that the use oftert-butyl alkoxide is critical for the exergonic formation of an arylsilver intermediate, and the results were further supported by density functional theory calculations.
- Lee, Mijung,Hwang, Young Kyu,Kwak, Jaesung
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supporting information
p. 3136 - 3144
(2021/09/30)
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- Photoinduced and Palladium-Catalyzed Remote Desaturation of Amide Derivatives
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A photoinduced and palladium-catalyzed remote desaturation of O-acyl hydroxamides to unsaturated amides under mild conditions has been achieved. The formation of the alkyl Pd(II) intermediate by the recombination of alkyl radical and Pd(I) species is critical to achieve this efficient and selective desaturation of alkanes. This reaction features good site-selectivity, is terminal oxidant-free, and produces moderate to excellent yields for a variety of unsaturated amides. Remarkably, this approach enables late-stage desaturation of complex and biologically important molecules.
- Jin, Weiwei,Yu, Shouyun
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p. 6931 - 6935
(2021/09/11)
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- p-TSA-Based DESs as “Active Green Solvents” for Microwave Enhanced Cyclization of 2-Alkynyl-(hetero)-arylcarboxylates: an Alternative Access to 6-Substituted 3,4-Fused 2-Pyranones
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In this paper, we describe the use of p-TSA based Deep Eutectic Solvents (DESs) as alternative environmental-friendly “active” solvents for the microwave-mediated synthesis of 6-substituted 3,4-fused 2-pyranones, and in particular isocoumarins, starting from 2-alkynyl-(hetero)arylcarboxylates. When the alkyne terminus bears a neutral or an electron-donating group (EDG), the reactions are fast, clean and highly regioselective, to give the 6-endo-dig cyclization products in good to excellent yields. For substrates bearing an electron-withdrawing group (EWG) on the alkyne end, the regioselectivity can be tuned by adding a small amount of silver(I) triflate as co-catalyst. DES was demonstrated to be reusable without loss of efficiency in terms of reaction yields. Based on experimental evidence and previous findings, two competitive mechanisms working simultaneously are proposed to explain the outcomes and the regioselectivity issues.
- Curti, Fabiola,Tiecco, Matteo,Pirovano, Valentina,Germani, Raimondo,Caselli, Alessandro,Rossi, Elisabetta,Abbiati, Giorgio
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p. 1904 - 1914
(2019/02/26)
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- Microwave-Assisted Synthesis of Sulfurated Heterocycles with Herbicidal Activity: Reaction of 2-Alkynylbenzoic Acids with Lawesson's Reagent
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The reactivity of 2-alkynylbenzoic acids toward Lawesson's reagent (LR) under microwave irradiation (300 W, 100 °C, CH2Cl2) was assessed. It was found that, depending on reaction conditions, either a dithionation- or a monothionation-cycloisomerization process takes place with formation of important sulfurated heterocycles. In particular, using 1 equivalent of LR for 1 h, dithionation occurred, with formation of benzo[c]thiophene-1(3H)-thiones or 1H-isothiochromene-1-thiones, while with 0.5 equiv. of LR for 10–30 min, monothionated products were selectively obtained (benzo[c]thiophen-1(3H)-ones or 1H-isothiochromen-1-ones). The regiochemical output of the process strongly depended on the substitution pattern of the starting 2-alkynylbenzoic acid derivatives. These compounds were also assayed as potential herbicides by assessing their phytotoxic activity on seedling growth and development of the model species Arabidopsis thaliana. All compounds, to different extents, influenced the morpho-physiological parameters that were monitored; in particular, the fresh weight (FW) was significantly affected, with ED50 values ranging from 4.81–63.7 μM.
- Giofrè, Salvatore V.,Mancuso, Raffaella,Araniti, Fabrizio,Romeo, Roberto,Iannazzo, Daniela,Abenavoli, Maria Rosa,Gabriele, Bartolo
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p. 942 - 950
(2019/07/31)
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- Silver triflate/: P -TSA co-catalysed synthesis of 3-substituted isocoumarins from 2-alkynylbenzoates
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In this paper, we describe the silver triflate/p-toluenesulfonic acid co-catalysed synthesis of seventeen isocoumarins and two thieno[2,3-c]pyran-7-ones starting from 2-alkynylbenzoates and 3-alkynylthiophene-2-carboxylates, respectively. The reaction proceeds with absolute regioselectivity under mild reaction conditions and low catalyst loading, to afford the desired products in good to excellent yields. A conceivable reaction mechanism is proposed and supported by isotope-exchange tests, 1H NMR studies and ad hoc experiments.
- Gianni, Jonathan,Pirovano, Valentina,Abbiati, Giorgio
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supporting information
p. 3213 - 3219
(2018/05/17)
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- Direct Transformation of Arylamines to Aryl Halides via Sodium Nitrite and N-Halosuccinimide
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A one-pot universal approach for transforming arylamines to aryl halides via reaction with sodium nitrite (NaNO2) and N-halosuccinimide (NXS) in DMF at room temperature under metal- and acid-free condition is described. This new protocol that is complementary to the Sandmeyer reaction, is suggested to involve the in situ generation of nitryl halide induce nitrosylation of aryl amine to form the diazo intermediate which is halogenated to furnish the aryl halide.
- Mukhopadhyay, Sushobhan,Batra, Sanjay
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supporting information
p. 14622 - 14626
(2018/09/21)
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- Synthesis of photovoltaic conjugated polymers
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A method of making a fluorothieno[3,4-b]thiophene derivatives and photovoltaic polymers containing same using 3-bromothiophene-2-carboxylic acid as a starting material. This synthetic route provides an easier synthesis as well as greater yield and a purer product, which produces superior results over the prior art less pure products. The resulting materials can be used in a variety of photovoltaic applications and devices, especially solar cells.
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Page/Page column 6; 9; 10
(2017/10/28)
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- Amide compound and its preparation method, pharmaceutical composition and use thereof
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The present invention relates to amide compounds as shown by structural formula (I). The compounds are low absorbable TGR5 agonists and can be used to treat type II diabetes, obesity, liver or intestine chronic inflammatory diseases.
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Paragraph 0473-0476
(2017/10/28)
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- Palladium NNC Pincer Complex as an Efficient Catalyst for the Cycloisomerization of Alkynoic Acids
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A two-step (nucleophilic substitution/palladation by oxidative addition) sequence provides a high-yielding access to a non-symmetrical palladium NNC pincer complex. A number of terminal and internal alkynoic acids with different substitution patterns at the α- and β-positions are regio- and diastereoselectively cycloisomerized to the corresponding exocyclic enol lactones in the presence of exceedingly low amounts of the latter palladium complex, so that unprecedented turnover numbers and frequencies ranging from 1,000,000 to 700,000 and from 41,667 to 9722 h?1, respectively, are achieved. The optimized protocol, based on the use of a catalytic amount of triethylamine as base, allows an easy real-time monitoring of the reaction by NMR spectroscopy. Several pieces of evidence in favor of the direct participation of the above pincer complex as the catalyst of the reaction have been gathered from kinetic and poisoning experiments. (Figure presented.).
- Conde, Nerea,SanMartin, Raul,Herrero, María Teresa,Domínguez, Esther
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supporting information
p. 3283 - 3292
(2016/10/21)
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- 7-(MORPHOLINYL)-2-(N-PIPERAZINYL) METHYL THIENO [2, 3-C] PYRIDINE DERIVATIVES AS ANTICANCER DRUGS
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The present invention relates to novel series of substituted 7-(morpholinyl)-2-(N-piperazinyl)-methyl thieno [2, 3-c] pyridines of the following structure of formula I. Where in R1, R2, R3 and R4 are defined.
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Page/Page column 27; 28
(2016/06/28)
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- NOVEL COMPOUNDS AS CHLORIDE CHANNEL BLOCKING AGENT
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Disclosed is a novel compound to function as a calcium-dependent chloride channel blocking agent.
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Paragraph 0068; 0069; 0070; 0071; 0072
(2015/06/03)
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- Efficient synthesis of novel thieno[3,2-b]-, [2,3-c]- and [3,2-c]pyridones by Sonogashira coupling of bromothiophenes with terminal alkynes and subsequent intramolecular C-N bond-forming reaction
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The coupling of bromothiophenes with terminal alkynes using triethylamine or diisopropyl amine under Sonogashira conditions (PdCl2(PPh 3)2, CuI) followed by subsequent addition of amines or ammonium to the intermediate thienyl acetylenes represents a novel access to a wide range of thieno[3,2-b]-, [2,3-c]-, and [3,2-c]pyridones under basic conditions and in excellent yields.
- Iaroshenko, Viktor O.,Ali, Sajid,Babar, Tariq Mahmood,Abbasi, Muhammad S.A.,Sosnovskikh, Vyacheslav Ya,Villinger, Alexander,Tolmachev, Andrey,Langer, Peter
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p. 3167 - 3181
(2013/04/24)
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- Design and synthesis of condensed thienocoumarins by Suzuki-Miyaura reaction/lactonization tandem protocol
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A concise and efficient approach to a series of chromen-4-ones with fused thiophene ring has been developed using the Suzuki-Miyaura reaction of bromothiophene-2- and 3-carboxylates with 2-methoxyboronic acids and subsequent cyclization of prepared alkyl (2-methoxy)aryl thiophene-2- and 3-carboxylates under the action of BBr3/KOtBu. Starting bromothiophenes are easily obtained from corresponding commercially available aminothiophenes by diazotization/bromination reaction.
- Iaroshenko, Viktor O.,Ali, Sajid,Mkrtchyan, Satenik,Gevorgyan, Ashot,Babar, Tariq Mahmood,Semeniuchenko, Volodymyr,Hassan, Zahid,Villinger, Alexander,Langer, Peter
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supporting information
p. 7135 - 7139
(2013/01/15)
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- 1-(2-PHENOXYMETHYLHETEROARYL)PIPERIDINE AND PIPERAZINE COMPOUNDS
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The invention relates to compounds of formula I: where X, HAr, a, and R1 through R6 are as defined in the specification, or a pharmaceutically acceptable salt thereof. The compounds of formula I are serotonin and norepinephrine reuptake inhibitors. The invention also relates to pharmaceutical compositions comprising such compounds; methods of using such compounds; and process and intermediates for preparing such compounds.
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Page/Page column 33-34
(2011/10/10)
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- MACROCYCLIC OXIMYL HEPATITIS C SERINE PROTEASE INHIBITORS
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The present invention relates to compounds of Formula (I), or pharmaceutically acceptable salts, esters, or prodrugs thereof: which inhibit serine protease activity, particularly the activity of hepatitis C virus (HCV) NS3-NS4A protease. Consequently, the compounds of the present invention interfere with the life cycle of the hepatitis C virus and are also useful as antiviral agents. The present invention further relates to pharmaceutical compositions comprising the aforementioned compounds for administration to a subject suffering from HCV infection. The invention also relates to methods of treating an HCV infection in a subject by administering a pharmaceutical composition comprising a compound of the present invention.
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Page/Page column 63
(2009/07/18)
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- Synthesis of novel highly active thiophene and benzothiophene containing diphosphine ligands and their use in the asymmetric allylation of catechol
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Novel thiophene and benzothiophene containing diphosphine ligands 5-8 with a chiral cyclohexyl diamine backbone have been prepared and used in the asymmetric allylation of catechol. The advantage of these new ligands is their high reactivity and excellent
- Tietze, Lutz F.,Lohmann, J. Klaas,Stadler, Christian
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p. 1113 - 1116
(2007/10/03)
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- Synthesis and antitumour activity of new derivatives of flavone-8- acetic acid (FAA). Part 31): 2-Heteroaryl derivatives
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A range of 14 derivatives of flavone-8-acetic acid (FAA) with a heterocyclic substituent in place of the 2-phenyl group have been prepared and their anti-tumour activity evaluated in vitro against a panel of human and murine tumour cell lines and in vivo against MAC 15A. Some of the compounds, notably 2c,d and s, showed significant in vivo activity and these require further studies in order to evaluate their potential for development.
- Aitken, R. Alan,Bibby, Michael C.,Bielefeldt, Florian,Double, John A.,Laws, Andrea L.,Mathieu, Anne-Laure,Ritchie, Robert B.,Wilson, David W. J.
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p. 405 - 411
(2007/10/03)
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- THE BEHAVIOUR OF VICINAL ALKYL AMINOTHIOPHENECARBOXYLATES IN THE SANDMEYER AND SCHIEMANN REACTIONS
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The diazotization of vicinal alkyl aminothiophenecarboxylates has been studied. 3-Amino compounds gave clear diazonium salts which yielded the expected halo derivatives in the Sandmeyer and Schiemann conditions.However, 2-amino compounds yielded self-coupling products.
- Corral, Carlos,Lasso, Ana,Lissavetzky, Jaime,Alvarez-Insua, Alberto Sanchez,Valdeolmillos, Ana M.
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p. 1431 - 1435
(2007/10/02)
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