- C?H Methylation of Iminoamido Heterocycles with Sulfur Ylides**
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The direct methylation of N-heterocycles is an important transformation for the advancement of pharmaceuticals, agrochemicals, functional materials, and other chemical entities. Herein, the unprecedented C(sp2)-H methylation of iminoamido heterocycles as nucleoside base analogues is described. Notably, trimethylsulfoxonium salt was employed as a methylating agent under aqueous conditions. A wide substrate scope and excellent level of functional-group tolerance were attained. Moreover, this method can be readily applied to the site-selective methylation of azauracil nucleosides. The feasibility of gram-scale reactions and various transformations of the products highlight the synthetic potential of the developed method. Combined deuterium-labeling experiments aided the elucidation of a plausible reaction mechanism.
- Ghosh, Prithwish,Kwon, Na Yeon,Kim, Saegun,Han, Sangil,Lee, Suk Hun,An, Won,Mishra, Neeraj Kumar,Han, Soo Bong,Kim, In Su
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supporting information
p. 191 - 196
(2020/10/29)
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- Catalyst-Free Decarbonylative Trifluoromethylthiolation Enabled by Electron Donor-Acceptor Complex Photoactivation
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A catalyst- and additive-free decarbonylative trifluoromethylthiolation of aldehyde feedstocks has been developed. This operationally simple, scalable, and open-to-air transformation is driven by the selective photoexcitation of electron donor-acceptor (EDA) complexes, stemming from the association of 1,4-dihydropyridines (donor) with N-(trifluoromethylthio)phthalimide (acceptor), to trigger intermolecular single-electron transfer events under ambient- and visible light-promoted conditions. Extension to other electron acceptors enables the synthesis of thiocyanates and thioesters, as well as the difunctionalization of [1.1.1]propellane. The mechanistic intricacies of this photochemical paradigm are elucidated through a combination of experimental efforts and high-level quantum mechanical calculations [dispersion-corrected (U)DFT, DLPNO-CCSD(T), and TD-DFT]. This comprehensive study highlights the necessity for EDA complexation for efficient alkyl radical generation. Computation of subsequent ground state pathways reveals that SH2 addition of the alkyl radical to the intermediate radical EDA complex is extremely exergonic and results in a charge transfer event from the dihydropyridine donor to the N-(trifluoromethylthio)phthalimide acceptor of the EDA complex. Experimental and computational results further suggest that product formation also occurs via SH2 reaction of alkyl radicals with 1,2-bis(trifluoromethyl)disulfane, generated in-situ through combination of thiyl radicals. (Figure presented.).
- Lipp, Alexander,Badir, Shorouk O.,Dykstra, Ryan,Gutierrez, Osvaldo,Molander, Gary A.
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supporting information
p. 3507 - 3520
(2021/06/11)
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- Visible-Light-Induced Regioselective Dicarbonylation of Indolizines with Oxoaldehydes via Direct C-H Functionalization
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A metal-free system for regioselective dehydrogenative cross-couplings between indolizines and oxoaldehydes catalyzed by visible light under mild conditions has been described. As an atom economical and eco-friendly protocol, the reaction proceeds in good yields using inexpensive, readily available visible-light sources and the environmentally friendly oxidant oxygen. Various valuable 1,2-dicarbonyl derivatives attached to an indolizine core were easily accessed by the direct dicarbonylation of the sp2 C-H bond.
- Teng, Lili,Liu, Xiang,Guo, Pengfeng,Yu, Yue,Cao, Hua
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supporting information
p. 3841 - 3845
(2020/05/08)
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- SMALL MOLECULE INHIBITORS OF NF-kB INDUCING KINASE
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The present invention relates to compounds that inhibit NIK and pharmaceutical compositions comprising such compounds and methods of using the same. These compounds and pharmaceutical compositions are envisaged to be useful for preventing or treating diseases such as cancer (such as B-cell malignancies including leukemias, lymphomas and myeloma), inflammatory disorders, autoimmune disorders, immunodermatologic disorders such as palmoplantar pustulosis and hidradenitis suppurativa, and metabolic disorders such as obesity and diabetes.
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Page/Page column 324
(2020/12/11)
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- Synthesis method of piperazine derivative
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The invention discloses a synthesis method of a piperazine derivative, namely 3-(3-nitrophenyl)piperazine-1-tert-butyl carboxylate. 1-(3-nitrophenyl)ethanone is taken as a starting material and is subjected to oxidation, cyclization and Boc protection so
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Paragraph 0020-0022
(2018/03/24)
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- Synthesis of 2-acyl-benzo[1,3-d]selenazoles via domino oxidative cyclization of methyl ketones with bis(2-aminophenyl) diselenide
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A general, practical and simple one-pot synthesis of 2-acyl-benzo[1,3-d]selenazoles was developed by reacting a wide range of 2-arylethane-1,2-diones, generated in situ from commercially available aryl methyl ketones, with bis(2-aminophenyl) diselenide, promoted by Na2S2O5 in DMSO at 100 °C. Comparatively, the reactions were conducted under conventional heating and microwave irradiation. The use of focused microwave irradiation drastically decreased the reaction time from 48 to 2 h with a gain in the reaction yield for most cases. Still, 2-phenylacyl-benzo[1,3-d]selenazole was elected to react with sodium borohydride and butylmagnesium bromide, giving the respective secondary and tertiary alcohols under mild reaction conditions.
- Balaguez, Renata A.,Betin, Eduardo S.,Barcellos, Thiago,Lenard?o, Eder J.,Alves, Diego,Schumacher, Ricardo F.
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supporting information
p. 1483 - 1487
(2017/02/23)
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- Discovery of novel 2-(3-phenylpiperazin-1-yl)-pyrimidin-4-ones as glycogen synthase kinase-3β inhibitors
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We herein describe the results of further evolution of glycogen synthase kinase (GSK)-3β inhibitors from our promising compounds containing a 2-phenylmorpholine moiety. Transformation of the morpholine moiety into a piperazine moiety resulted in potent GSK-3β inhibitors. SAR studies focused on the phenyl moiety revealed that a 4-fluoro-2-methoxy group afforded potent inhibitory activity toward GSK-3β. Based on docking studies, new hydrogen bonding between the nitrogen atom of the piperazine moiety and the oxygen atom of the main chain of Gln185 has been indicated, which may contribute to increased activity compared with that of the corresponding phenylmorpholine analogues. Effect of the stereochemistry of the phenylpiperazine moiety is also discussed.
- Usui, Yoshihiro,Uehara, Fumiaki,Hiki, Shinsuke,Watanabe, Kazutoshi,Tanaka, Hiroshi,Shouda, Aya,Yokoshima, Satoshi,Aritomo, Keiichi,Adachi, Takashi,Fukunaga, Kenji,Sunada, Shinji,Nabeno, Mika,Saito, Ken-Ichi,Eguchi, Jun-ichi,Yamagami, Keiji,Asano, Shouichi,Tanaka, Shinji,Yuki, Satoshi,Yoshii, Narihiko,Fujimura, Masatake,Horikawa, Takashi
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p. 3726 - 3732
(2017/07/27)
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- Regiospecific one-pot, combinatorial synthesis of new substituted pyrimido[4,5-c]pyridazines as potential monoamine oxidase inhibitors
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New 3-aryl-6-methylpyrimido[4,5-c]pyridazine-5,7(6H ,8H)-diones and 3-aryl-6-ethyl-7-thioxo-7,8-dihydropyrimido[4,5- c]pyridazin-5(6H)-ones were efficiently synthesized via a regiospecific one-pot reaction of N -methylbarbituric acid and N -ethyl-2-thiobarbituric acid with various arylglyoxal monohydrates in the presence of hydrazine dihydrochloride in ethanol at 50°C. The target compounds were obtained in high yields and were regioisomerically pure after recrystallization. These new heterocycles may act as potential MAOB inhibitors.
- Rimaz, Mehdi,Pourhossein, Paria,Khalili, Behzad
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p. 244 - 254
(2015/05/27)
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- Two efficient one-pot approaches for regioselective synthesis of new 3-arylpyridazino[4,3-c]quinolin-5(6H)-ones
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Two efficient regioselective approaches for the one-pot synthesis of 3-arylpyridazino[4,3-c]quinolin-5(6H)-one derivatives are reported, by the three-component reaction of arylglyoxal monohydrates, quinoline-2,4-diol, and hydrazinium dihydrochloride or hydrazine hydrate in ethanol and pyridine. In ethanol, the reactions were catalyzed by 1,4-diazobicyclo[2,2,2]octane. The features of both procedures are high regioselectivity, mild reaction conditions, good to high yields, and operational simplicity.
- Rimaz, Mehdi
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p. 1529 - 1534
(2015/10/20)
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- Syntheses, Cholinesterases Inhibition, and Molecular Docking Studies of Pyrido[2,3-b]pyrazine Derivatives
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Cholinesterases, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), have a role in cholinergic deficit which evidently leads to Alzheimer's disease (AD). Inhibition of cholinesterases with small molecules is an attractive strategy in AD therapy. This study demonstrates synthesis of pyrido[2,3-b]pyrazines (6a-6q) series, their inhibitory activities against both cholinesterases, AChE and BChE, and molecular docking studies. The bioactivities data of pyrido[2,3-b]pyrazines showed 3-(3′-nitrophenyl)pyrido[2,3-b]pyrazine 6n a potent dual inhibitor among the series against both AChE and BChE with IC50 values of 0.466 ± 0.121 and 1.89 ± 0.05 μm, respectively. The analogues 3-(3′-methylphenyl)pyrido[2,3-b]pyrazine 6c and 3-(3′-fluorophenyl)pyrido[2,3-b]pyrazine 6f were found to be selective inhibition for BChE with IC50 values of 0.583 ± 0.052 μm and AChE with IC50 value of 0.899 ± 0.10 μm, respectively. Molecular docking studies of the active compounds suggested the putative binding modes with cholinesterases. The potent compounds among the series could potentially serves as good leads for the development of new cholinesterase inhibitors. A series of pyrido[2,3-b]pyrazine (6a-6q) derivatives has been synthesized and evaluated for inhibitory activities against cholinesterases; acetylcholinesterase, and butyrylcholinesterase. Molecular docking of active compounds was also performed to suggest the putative binding modes with cholinesterases.
- Hameed, Abdul,Zehra, Syeda T.,Shah, Syed J. A.,Khan, Khalid M.,Alharthy, Rima D.,Furtmann, Norbert,Bajorath, Jürgen,Tahir, Muhammad N.,Iqbal, Jamshed
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p. 1115 - 1120
(2015/10/28)
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- Metal free one-pot synthesis of α-ketoamides from terminal alkenes
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A practical approach towards the synthesis of α-ketoamides from readily available terminal alkenes (styrenes) has been developed. Use of inexpensive I2/2-iodoxybenzoic acid (IBX) in dimethyl sulphoxide (DMSO) as an oxidant under metal free one-pot conditions makes this methodology versatile.
- Dutta, Sayan,Kotha, Surya Srinivas,Sekar, Govindasamy
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p. 47265 - 47269
(2015/06/16)
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- Synthesis of 2-aroyl-(4 or 5)-aryl-1H-imidazoles and 2-hydroxy-3,6-diaryl- pyrazines via a cascade process
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The synthesis of (4 or 5)-aryl-2-aroyl-1H-imidazoles and 2-hydroxy-3,6-diarylpyrazines from aryl methyl ketones via a cascade process of DMSO-HBr oxidation and Debus reaction was investigated. Owing to the simple starting materials, mild conditions, easy operation, high bioactivity of imidazole and pyrazine derivatives, this protocol has great potential in medicinal chemistry.
- Liu, Cong,Dai, Rong J.,Yao, Guo W.,Deng, Yu L.
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p. 146 - 163
(2014/04/17)
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- Quinoxaline derivatives: Novel and selective butyrylcholinesterase inhibitors
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Alzheimer's disease (AD) is a progressive brain disorder which occurs due to lower levels of acetylcholine (ACh) neurotransmitters, and results in a gradual decline in memory and other cognitive processes. Acetycholinesterase (AChE) and butyrylcholinesterase (BChE) are considered to be primary regulators of the ACh levels in the brain. Evidence shows that AChE activity decreases in AD, while activity of BChE does not change or even elevate in advanced AD, which suggests a key involvement of BChE in ACh hydrolysis during AD symptoms. Therefore, inhibiting the activity of BChE may be an effective way to control AD associated disorders. In this regard, a series of quinoxaline derivatives 1-17 was synthesized and biologically evaluated against cholinesterases (AChE and BChE) and as well as against achymotrypsin and urease. The compounds 1-17 were found to be selective inhibitors for BChE, as no activity was found against other enzymes. Among the series, compounds 6 (IC50 = 7.7 ± 1.0μM) and 7 (IC50 = 9.7 ± 0.9 μM) were found to be the most active inhibitors against BChE. Their IC50 values are comparable to the standard, galantamine (IC50 = 6.6 ± 0.38 μM). Their considerable BChE inhibitory activity makes them selective candidates for the development of BChE inhibitors. Structure-activity relationship (SAR) of this new class of selective BChE inhibitors has been discussed.
- Zeb, Aurang,Hameed, Abdul,Khan, Latifullah,Khan, Imran,Dalvandi, Kourosh,Choudhary, M. Iqbal,Basha, Fatima Z.
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p. 724 - 729
(2015/04/14)
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- A simple three-component synthesis of 3-amino-5-arylpyridazine-4- carbonitriles
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New 3-amino-5-arylpyridazine-4-carbonitriles have been synthesized by a one-pot three-component reaction of malononitrile with arylglyoxals in the presence of hydrazine hydrate at room temperature in water and ethanol.
- Khalafy,Rimaz,Farajzadeh,Ezzati
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p. 179 - 182
(2013/07/26)
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- An efficient one-pot protocol for regioselective synthesis of 3-aryl-6,8-dialkyl-7-thioxo-7,8-dihydropyrimido[4,5-c ] pyridazine-5(6 H)-ones
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A series of 3-aryl-6,8-dialkyl-7-thioxo-7,8-dihydropyrimido[4,5-c] pyridazine-5(6H)-one derivatives have been regioselectively synthesized via the one-pot three-component reaction of 1,3-dimethylthiobarbituric acid and 1,3-diethylthiobarbituric acid with various arylglyoxals in the presence of hydrazinium dihydrochloride in warm ethanol. These new substituted pyrimidopyridazines may be potential monoamine oxidase inhibitors.
- Khalafy, Jabbar,Rimaz, Mehdi,Rabiei, Hossein,Panahi, Leila
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p. 395 - 406
(2013/09/23)
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- A regiospecific One-Pot, Three component synthesis of 4-Aryl-6,8- dimethylpyrimido[4,5-c]pyridazine-5,7(6H,8H)-diones as New potential monoamine oxidase inhibitors
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A series of new 4-aryl-6,8-dimethylpyrimido[4,5-c]pyridazine-5,7(6H,8H)- diones have been synthesized via three component reaction of 1,3-dimethylbarbituric acid with arylglyoxals in the presence of hydrazinium dihydrochloride in ethanol. All of these derivatives may act as potential monoamine oxidase inhibitors.
- Khalafy, Jabbar,Rimaz, Mehdi,Panahi, Leila,Rabiei, Hossein
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scheme or table
p. 2428 - 2432
(2012/06/01)
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- Structure-activity Relationship of Herbicidal 2,3-Dicyano-5-Substituted Pyrazines
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Sixty six 2,3-dicyano-5-substituted pyrazines were synthesized and their herbicidal activities against barnyard grass were measured in pot tests to clarify the relationship between chemical structure and activity.The activity of 59 derivatives was related parabolically to the hydrophobic substituent parameter at the 5-position of the pyrazine ring.
- Nakamura, Akira,Ataka, Toshiei,Segawa, Hirozo,Takeuchi, Yasutomo,Takematsu, Tetsuo
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p. 1555 - 1560
(2007/10/02)
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