- Annulation-retro-Claisen cascade of bifunctional peroxides for the synthesis of lactone natural products
-
A new and highly efficient annulation-retro-Claisen cascade, which involves the [4 + 1] or [5 + 1] annulation of α-benzoylacetates with bielectrophilic peroxides and a subsequent debenzoylation process under mild basic conditions, has been developed for the rapid construction of valuable tetrahydrofuran- and dihydropyran-2-carboxylates in good yields. By employing the new reaction, the unified total synthesis of γ- and δ-lactone natural products such as (±)-tanikolide, (±)-goniothalamins, (±)-7-epi-goniodiol, and (±)-plakolide A has been accomplished in 4-7 steps.
- Hu, Lin,Li, Jialin,Li, Xuemin,Xu, Qianlan
-
p. 274 - 277
(2022/01/03)
-
- Trifluoroethanol as a Unique Additive for the Chemoselective Electrooxidation of Enamines to Access Unsymmetrically Substituted NH-Pyrroles
-
An electrochemical method for the synthesis of unsymmetrically substituted NH-pyrroles is described. The synthetic strategy comprises a challenging heterocoupling between two structurally diverse enamines via sequential chemoselective oxidation, addition,
- Baidya, Mrinmay,De Sarkar, Suman,Maiti, Debabrata,Roy, Lisa
-
supporting information
(2021/12/23)
-
- Electrochemical Oxidative Cyclization: Synthesis of Polysubstituted Pyrrole from Enamines
-
A conceptually novel method for the preparation of pyrrole is described by electrochemical-oxidation-induced intermolecular annulation via enamines. In a simple undivided cell, based on a sodium acetate-facilitated, polysubstituted pyrrole derivations has been facilely synthesized under external oxidant-free condition. This electrosynthetic approach providing an environmentally benign protocol for C?C bond cross-coupling and oxidative annulation, which features unparalleled broad scope of substrates and practicality.
- Chen, Zhiwei,Shi, Guang,Tang, Wei,Sun, Jie,Wang, Wenxing
-
supporting information
p. 951 - 955
(2021/02/03)
-
- Construction of isoxazolone-fused phenanthridinesviaRh-catalyzed cascade C-H activation/cyclization of 3-arylisoxazolones with cyclic 2-diazo-1,3-diketones
-
A Rh(iii)-catalyzed cascade C-H activation/intramolecular cyclization of 3-aryl-5-isoxazolones with cyclic 2-diazo-1,3-diketones was described, leading to the formation of isoxazolo[2,3-f]phenanthridine skeletons. The protocol features the simultaneous one-pot formation of two new C-C/C-N bonds and one heterocycle in moderate-to-good yields with good functional group compatibility. It is amenable to large-scale synthesis and further transformation.
- Hu, Wangcheng,He, Xinwei,Zhou, Tongtong,Zuo, Youpeng,Zhang, Shiwen,Yang, Tingting,Shang, Yongjia
-
supporting information
p. 552 - 556
(2021/02/06)
-
- Sulfur-controlled and rhodium-catalyzed formal (3 + 3) transannulation of thioacyl carbenes with alk-2-enals and mechanistic insights
-
A rhodium-catalyzed denitrogenative formal (3 + 3) transannulation of 1,2,3-thiadiazoles with alk-2-enals is achieved, producing 2,3-dihydrothiopyran-4-ones in moderate to excellent yields. An inverse KIE of 0.49 is obtained, suggesting the reversibility of the oxidative addition of thioacyl Rh(i) carbenes to alk-2-enals. The late-stage structural modifications of steroid compounds are realized. Moreover, our studies show that thioacyl carbenes have different reactivities to those of α-oxo and α-imino carbenes, and highlight the importance of heteroatoms in deciding the reactivities of heterovinyl carbenes.
- Wu, Qiuyue,Dong, Ziyang,Xu, Jiaxi,Yang, Zhanhui
-
supporting information
p. 3173 - 3180
(2021/04/21)
-
- Iridium-Catalyzed Enantioselective and Diastereoselective Hydrogenation of Racemic β’-Keto-β-Amino Esters via Dynamic Kinetic Resolution
-
An iridium/f-diaphos catalytic system for the enantioselective hydrogenation of α-substituted β-ketoesters via dynamic kinetic resolution is reported. The desired anti β’-hydroxy-β-amino esters were obtained in moderate to good yields (60–95%) with 72–99% ees and 91:9 to 99:1 drs. This protocol tolerates various functional groups and could be easily conducted on gram scale with lower catalyst loading (TON up to 9100). (Figure presented.).
- He, Jiayin,Huang, An,Ling, Fei,Wang, Shiliang,Wang, Yifan,Wang, Ze,Zhao, Xianghua,Zhong, Weihui
-
supporting information
p. 4714 - 4719
(2021/09/02)
-
- Synthesis of Dithiolethiones and Identification of Potential Neuroprotective Agents via Activation of Nrf2-Driven Antioxidant Enzymes
-
Oxidative stress is implicated in the pathogenesis of a wide variety of neurodegenerative disorders, and accordingly, dietary supplement of exogenous antioxidants or/and upregulation of the endogenous antioxidant defense system are promising for therapeutic intervention or chemoprevention of neurodegenerative diseases. Nrf2, a master regulator of the cellular antioxidant machinery, cardinally participates in the transcription of cytoprotective genes against oxidative/electrophilic stresses. Herein, we report the synthesis of 59 structurally diverse dithiolethiones and evaluation of their neuroprotection against 6-hydroxydopamine-or H2O2-induced oxidative damages in PC12 cells, a neuron-like rat pheochromocytoma cell line. Initial screening identified compounds 10 and 11 having low cytotoxicity but conferring remarkable protection on PC12 cells from oxidative-mediated damages. Further studies demonstrated that both compounds upregulated a battery of antioxidant genes as well as corresponding genes' products. Significantly, silence of Nrf2 expression abolishes cytoprotection of 10 and 11, indicating targeting Nrf2 activation is pivotal for their cellular functions. Taken together, the two lead compounds discovered here with potent neuroprotective functions against oxidative stress via Nrf2 activation merit further development as therapeutic or chemopreventive candidates for neurodegenerative disorders.
- Bai, Feifei,Fang, Jianguo,Song, Zi-Long,Zhang, Baoxin
-
p. 2214 - 2231
(2020/03/06)
-
- Radical Aza-Cyclization of α-Imino-oxy Acids for Synthesis of Alkene-Containing N-Heterocycles via Dual Cobaloxime and Photoredox Catalysis
-
Nitrogen-containing heterocycles are prevalent in both naturally and synthetically bioactive molecules. We report herein an unprecedented protocol for radical aza-cyclization of α-imino-oxy acids with pendant alkenes via synergistic photoredox and cobaloxime catalysis. With or without alkenes as the intermolecular cross-coupling partners, the transformation provides a variety of corresponding alkene-containing dihydropyrrole products in satisfactory yields. In the presence of external alkenes, the tandem reaction generates E-selective coupling products with excellent chemo- and stereoselectivity.
- Tu, Jia-Lin,Liu, Jia-Li,Tang, Wan,Su, Ma,Liu, Feng
-
supporting information
p. 1222 - 1226
(2020/02/15)
-
- An efficient route for the synthesis of N-(1H-benzo[d]imidazol-2-yl)benzamide derivatives promoted by CBr4 in one pot
-
A metal-free one-pot method for the synthesis of N-(1H-benzo[d]imidazol-2-yl)benzamide derivatives was proposed mediated by CBr4. The reaction went through ring formation and opening processes with only two protons leaving and the thermodynamically favorable products were selectively formed in moderate to good yields.
- Li, Songhua,Li, Yunyi,Ma, Chen,Xie, Caixia
-
-
- Double Enzyme-Catalyzed One-Pot Synthesis of Enantiocomplementary Vicinal Fluoro Alcohols
-
A double-enzyme-catalyzed strategy for the synthesis of enantiocomplementary vicinal fluoro alcohols through a one-pot, three-step process including lipase-catalyzed hydrolysis, spontaneous decarboxylative fluorination, and subsequent ketoreductase-catalyzed reduction was developed. With this approach, β-ketonic esters were converted to the corresponding vicinal fluoro alcohols with high isolated yields (up to 92percent) and stereoselectivities (up to 99percent). This new cascade process addresses some issues in comparison with traditional methods such as environmentally hazardous reaction conditions and low stereoselectivity outcome.
- Fan, Jiajie,Lin, Xianfu,Peng, Yongzhen,Wang, Anlin,Wu, Qi,Xu, Jian,Xu, Weihua,Yu, Huilei
-
supporting information
(2020/07/24)
-
- Desymmetrization of meso-dicarbonatecyclohexene with β-Hydrazino carboxylic esters via a Pd-catalyzed allylic substitution cascade
-
The desymmetrization of meso-dicarbonatecyclohexene with β-hydrazino carboxylic esters has been achieved via a RuPHOX/Pd-catalyzed allylic substitution cascade for the construction of chiral hexahydrocinnoline derivatives with high performance. Mechanistic studies reveal that the reaction exploits a pathway different from that of our previous work and that the first nitrogen nucleophilic process is the rate-determining step. The protocol could be conducted on a gram scale without any loss of catalytic behavior, and the corresponding chiral hexahydrocinnolines can undergo diverse transformations.
- Xu, Kai,Zheng, Yan,Ye, Yong,Liu, Delong,Zhang, Wanbin
-
supporting information
p. 8836 - 8841
(2020/11/30)
-
- Toward Continuous-Flow Synthesis of Biologically Interesting Pyrazole Derivatives
-
A two-step continuous-flow synthesis of substituted pyrazole derivatives has been developed via the formation of vinylidene keto esters as key intermediates. Heterogeneous Ni2+-montmorillonite was found to be an efficient catalyst for orthoester condensation of 1,3-dicarbonyls under flow conditions. The intermediate reacted with methylhydrazine to afford pyrazole derivatives, for which suitable selection of a solvent played a key role in achieving high yields and excellent regioselectivities of the desired products. An application of this protocol has been demonstrated by the synthesis of a key intermediate for biologically active pyrazoles such as Bixafen. (Figure presented.).
- Das, Amrita,Ishitani, Haruro,Kobayashi, Shū
-
supporting information
p. 5127 - 5132
(2019/11/13)
-
- General [4 + 1] Cyclization Approach to Access 2,2-Disubstituted Tetrahydrofurans Enabled by Electrophilic Bifunctional Peroxides
-
A general [4 + 1] cyclization reaction of carbonyl nucleophiles with 2-iodomethylallyl peroxides, which function as unique electrophilic oxygen synthons, for the synthesis of a broad range of 2,2-disubstituted tetrahydrofurans is achieved under operationally simple conditions. The unprecedented asymmetric version of such reaction is also realized via chiral auxiliary-assisted cyclization, thus providing a distinct approach to access chiral tetrahydrofurans with high diastereoselectivities. The new method can be applied to the synthesis of core structure of posaconazole drug.
- Gao, Min,Zhao, Yukun,Zhong, Chen,Liu, Shengshu,Liu, Pengkang,Yin, Qi,Hu, Lin
-
supporting information
p. 5679 - 5684
(2019/08/01)
-
- Switching of Sulfonylation Selectivity by Nature of Solvent and Temperature: The Reaction of β-Dicarbonyl Compounds with Sodium Sulfinates under the Action of Iron-Based Oxidants
-
Selectivity of sulfonylation of β-keto esters with sodium sulfinates under the action of iron(III) salts as oxidants can be regulated by the type of solvent used and the reaction temperature. α-Sulfonyl β-keto esters are obtained when the process is conducted in THF/H2O solution at 40 °C. The change of the solvent to iPrOH/H2O and refluxing of a reaction mixture provides α-sulfonyl esters – the products of successive sulfonylation-deacylation. When β-diketones are applied as starting materials, only α-sulfonyl ketones are formed. The reaction pathway includes sulfonylation of dicabonyl compounds under the action of Fe(III) to form α-sulfonylated dicarbonyl compounds, which are then attacked by a solvent as the nucleophile, resulting in the products of successive sulfonylation-deacylation. Participation of the solvent in the reaction pathway determines the products structure.
- Mulina, Olga M.,Pirgach, Dmitry A.,Nikishin, Gennady I.,Terent'ev, Alexander O.
-
supporting information
p. 4179 - 4188
(2019/05/08)
-
- Synthesis and biochemical evaluation of lid-open D-amino acid oxidase inhibitors
-
Most of the known inhibitors of D-amino acid oxidase (DAAO) are small polar molecules recognized by the active site of the enzyme. More recently a new class of DAAO inhibitors has been disclosed that interacts with loop 218?224 at the top of the binding pocket. These compounds have a significantly larger size and more beneficial physicochemical properties than most reported DAAO inhibitors, however, their structure-activity relationship is poorly explored. Here we report the synthesis and evaluation of this type of DAAO inhibitors that open the lid over the active site of DAAO. In order to collect relevant SAR data we varied two distinct parts of the inhibitors. A systematic variation of the pendant aromatic substituents according to the Topliss scheme resulted in DAAO inhibitors with low nanomolar activity. The activity showed low sensitivity to the substituents investigated. The variation of the linker connecting the pendant aromatic moiety and the acidic headgroup revealed that the interactions of the linker with the enzyme were crucial for achieving significant inhibitory activity. Structures and activities were analyzed based on available X-ray structures of the complexes. Our findings might support the design of drug-like DAAO inhibitors with advantageous physicochemical properties and ADME profile.
- Szilágyi, Bence,Hargitai, Csilla,Kelemen, ádám A.,Rácz, Anita,Ferenczy, Gy?rgy G.,Volk, Balázs,Keser?, Gy?rgy M.
-
supporting information
(2019/01/31)
-
- Catalytic Mechanism Study on the 1,2- and 1,4-Transfer Hydrogenation of Ketimines and β-Enamino Esters Catalyzed by Axially Chiral Biscarboline-Based Alcohols
-
Axial N-O alcohols, which have two large carboline moieties connected to the axis were synthesized and used in catalytic enantioselective 1,2- and 1,4-transfer hydrogenations of total 26 ketimines and β-enamino esters. Excellent levels of enantioselectivity ranging from 91% to 99% were achieved by using catalyst (aS)-(S)-3,3′-bis((S)-2-(hydroxymethyl)pyrrolidine-1-carbonyl)-9,9′-dimethyl-9H,9′H-[1,1′-bipyrido[3,4-b]indole] 2-oxide. Interestingly, a mixture of (aS)-(S)-3,3′-bis((S)-2-(hydroxymethyl)pyrrolidine-1-carbonyl)-9,9′-dimethyl-9H,9′H-[1,1′-bipyrido[3,4-b]indole] 2-oxide and (aR)-(S)-3,3′-bis((S)-2-(hydroxymethyl)pyrrolidine-1-carbonyl)-9,9′-dimethyl-9H,9′H-[1,1′-bipyrido[3,4-b]indole] 2-oxide was also able to provide high enantioselectivities up to 95% that is the same as that using pure (aS)-(S)-3,3′-bis((S)-2-(hydroxymethyl)pyrrolidine-1-carbonyl)-9,9′-dimethyl-9H,9′H-[1,1′-bipyrido[3,4-b]indole] 2-oxide. A plausible catalytic mechanism was suggested and total four kinds of transition states (TS) including almost 60 TS structures were investigated using density functional theory (DFT) with different basis sets such as 6-311G(2d,p). The predicted activation energy data are consistent with the experimental results. (Figure presented.).
- Dong, Mengxian,Wang, Jie,Wu, Shijie,Zhao, Yang,Ma, Yangyang,Xing, Yongfei,Cao, Fei,Li, Longfei,Li, Zhenqiu,Zhu, Huajie
-
supporting information
p. 4602 - 4610
(2019/08/30)
-
- 6-AMINO-2,4-DIHYDROPYRANO [2,3-C] PYRAZOLES AND METHODS OF USE
-
The present invention generally relates to 6-amino-2,4-dihydropyrano [2,3-c] pyrazoles as a ubiquitin specific protease 7 (USP7) inhibitor useful for the treatment of diseases mediated by malfunction of USP7, such as inflammation, cancer, and immunological disorders. The invention described herein also pertains to pharmaceutical compositions and methods for treating diseases mediated by malfunction of USP7, in mammals using compounds disclosed herein.
- -
-
Paragraph 0097-0099; 0103
(2018/10/25)
-
- Substituted phenyl pyrazolone derivatives and preparation and application (by machine translation)
-
The present invention provides a substituted phenyl pyrazolone derivatives, in particular to a 2 - phenyl - pyrazoline - 3 - ketone compound and its pharmaceutically acceptable salt, solvate. The substituted acetic acid ethyl ester with sodium hydroxide in aqueous solution in the [...] reflux reaction, then in the palladium-carbon and hydrogen under the action of the hydrogenolysis benzyl, phenyl [...] obtained, with the bromochlorodifluoromethane alkane reaction to obtain the chloro, finally with the secondary amine on the condensation to obtain the target compound. The invention substituted phenyl pyrazoline compounds in vitro exhibits excellent capability of eliminating the free radicals, and have more strongly inhibit H3 receptor activity, exhibits excellent penetration of the blood brain barrier capacity, has a unique dual active, therefore, its for cerebral apoplexy, Alzheimer's disease, Parkinson's disease, progressive neurodegenerative diseases such as frozen sickness treatment has a unique clinical effect. The compound of the invention for treating central system system related disease and inflammatory disease application of the medicament. The formula structure is as follows: (by machine translation)
- -
-
Paragraph 0034; 0039; 0040
(2019/01/08)
-
- Enantioselective and Diastereoselective Ir-Catalyzed Hydrogenation of α-Substituted β-Ketoesters via Dynamic Kinetic Resolution
-
An iridium/f-amphol catalytic system for the enantioselective hydrogenation of α-substituted β-ketoesters via dynamic kinetic resolution is reported. The desired anti products were obtained in high yields (up to 98%) with good diastereoselectivity (up to 96:4 diastereometic ratio (dr)) and excellent enantioselectivity (up to >99% enantiomeric excess (ee)). A catalytic model is proposed to explain the stereoselectivity.
- Gu, Guoxian,Lu, Jiaxiang,Yu, Ouran,Wen, Jialin,Yin, Qin,Zhang, Xumu
-
supporting information
p. 1888 - 1892
(2018/04/16)
-
- In situ generation of nitrile oxides from copper carbene and tert -butyl nitrite: Synthesis of fully substituted isoxazoles
-
Herein, we present a novel [3 + 2] cycloaddition reaction of β-keto esters with nitrile oxides, which were generated in situ from copper carbene and tert-butyl nitrite. This three-component reaction provides new methodology for the direct synthesis of fully substituted isoxazole derivatives, featuring mild reaction conditions, readily accessible starting materials and simple operation. The experimental studies and DFT calculations suggest that the reaction starts with the generation of the key intermediate nitrile oxides, followed by a [3 + 2] cycloaddition reaction of β-keto esters to give the final isoxazole products.
- Chen, Rongxiang,Ogunlana, Abosede Adejoke,Fang, Shangwen,Long, Wenhao,Sun, Hongmei,Bao, Xiaoguang,Wan, Xiaobing
-
supporting information
p. 4683 - 4687
(2018/07/06)
-
- Iridium-Catalyzed Asymmetric Hydrogenation of Tetrasubstituted α-Fluoro-β-enamino Esters: Efficient Access to Chiral α-Fluoro-β-amino Esters with Two Adjacent Tertiary Stereocenters
-
An iridium-catalyzed highly efficient asymmetric hydrogenation of challenging tetrasubstituted α-fluoro-β-enamino esters was successfully developed using bisphosphine-thiourea (ZhaoPhos) as the ligand, which prepared a series of chiral α-fluoro-β-amino esters containing two adjacent tertiary stereocenters with high yields and excellent diastereoselectivities/enantioselectivities (73%-99% yields, >25:1 dr, 91%>99% ee, and turnover number (TON) values up to 8600), and no defluorinate byproduct was detected.
- Han, Zhengyu,Guan, Yu-Qing,Liu, Gang,Wang, Rui,Yin, Xuguang,Zhao, Qingyang,Cong, Hengjiang,Dong, Xiu-Qin,Zhang, Xumu
-
supporting information
p. 6349 - 6353
(2018/10/15)
-
- Rhodium-catalyzed asymmetric hydrogenation of tetrasubstituted β-acetoxy-α-enamido esters and efficient synthesis of droxidopa
-
A rhodium-catalyzed asymmetric hydrogenation of challenging tetrasubstituted β-acetoxy-α-enamido esters was developed, giving chiral β-acetoxy-α-amido esters in high yields with excellent enantioselectivities (up to >99% ee). The products could be easily transformed to β-hydroxy-α-amino acid derivatives which are valuable chiral building blocks and a novel route for the synthesis of droxidopa was also developed.
- Guan, Yu-Qing,Gao, Min,Deng, Xu,Lv, Hui,Zhang, Xumu
-
supporting information
p. 8136 - 8139
(2017/07/24)
-
- Bromide-Mediated C-H Bond Functionalization: Intermolecular Annulation of Phenylethanone Derivatives with Alkynes for the Synthesis of 1-Naphthols
-
Bromide-mediated intermolecular annulation of phenylethanone derivatives with alkynes has been developed, which allows for the regioselective formation of polysubstituted 1-naphthols. The usage of readily available bromine catalyst, broad substrate scope, and mild conditions make this protocol very practical. Mechanistic investigations reveal that the bromination of phenylethanone derivatives occurs to yield bromo-substituted intermediates, which react in situ with alkynes to furnish the desired 1-naphthols.
- Lu, Tao,Jiang, Ya-Ting,Ma, Feng-Ping,Tang, Zi-Jing,Kuang, Liu,Wang, Yu-Xuan,Wang, Bin
-
supporting information
p. 6344 - 6347
(2017/12/08)
-
- Synthesis and biological evaluation of pyrazolo[3,4-b]pyridin-4-ones as a new class of topoisomerase II inhibitors
-
A series of 1,3,6-triphenylpyrazolo[3,4-b]pyridin-4-one derivatives was designed, synthesized and evaluated for cytotoxic activity in A375 human melanoma and human erythroleukemia (HEL) cells. The new pyrazolopyridones displayed comparable activities to the antitumor compound etoposide. The inhibitory effect of compounds 17, 18, 27 and 32 against topoisomerase II-mediated cleavage activities was measured finding good correlation with the results obtained from MTS assay. Docking studies into bacterial topoisomerase II (DNA Gyrase), topoisomerase IIα and topoisomerase IIβ binding sites in the DNA binding interface were performed.
- Tabrizi, Mojgan Aghazadeh,Baraldi, Pier Giovanni,Baraldi, Stefania,Prencipe, Filippo,Preti, Delia,Saponaro, Giulia,Romagnoli, Romeo,Gessi, Stefania,Merighi, Stefania,Stefanelli, Angela,Fazzi, Debora,Borea, Pier Andrea,Maia, Rodolfo Couto,Romeiro, Nelilma C.,Fraga, Carlos A.M.,Barreiro, Eliezer J.
-
p. 342 - 353
(2016/10/11)
-
- A copper-mediated oxidative coupling route to 3H- and 1H-indoles from N-aryl-enamines
-
A facile copper(II)-mediated C-H bond oxidation and C-C bond formation procedure has been applied to the synthesis of indole derivatives. Intramolecular oxidative coupling of 3,3-disubstituted enamines proceeded using a non-expensive and air-stable copper
- Drouhin, Pauline,Taylor, Richard J. K.
-
supporting information
p. 2333 - 2336
(2015/04/22)
-
- PIGMENT ADDITIVE, PIGMENT COMPOSITION USING THE SAME, COLORING COMPOSITION, AND COLOR FILTER
-
PROBLEM TO BE SOLVED: To provide: a pigment additive exhibiting extremely excellent characteristics for obtaining fine pigment; and a pigment composition which realizes a color filter made using the pigment composition or a coloring composition using the
- -
-
-
- Synthesis and biological evaluation of pyrazolylthiazole carboxylic acids as potent anti-inflammatory-antimicrobial agents
-
Current Letter presents design, synthesis and biological evaluation of a novel series of pyrazolylthiazole carboxylates 1a-1p and corresponding acid derivatives 2a-2p. All 32 novel compounds were tested for their in vivo anti-inflammatory activity by carrageenan-induced rat paw edema method as well as for in vitro antimicrobial activity. All the tested compounds exhibited excellent AI activity profile. Three compounds 1p (R = Cl, R1 = Cl), 2c (R = H, R1 = F) and 2n (R = Cl, R1 = OCH3) were identified as potent anti-inflammatory agents exhibiting edema inhibition of 93.06-89.59which is comparable to the reference drug indomethacin (91.32%) after 3 h of carrageenan injection while most of the other compounds displayed inhibition ≥80%. In addition, pyrazolylthiazole carboxylic acids (2a-2p) also showed good antimicrobial profile. Compound 2h (R = OCH3, R1 = Cl) showed excellent antimicrobial activity (MIC 6.25 μg/mL) against both Gram positive bacteria comparable with the reference drug ciprofloxacin (MIC 6.25 μg/mL).
- Khloya, Poonam,Kumar, Satish,Kaushik, Pawan,Surain, Parveen,Kaushik, Dhirender,Sharma, Pawan K.
-
p. 1177 - 1181
(2015/03/14)
-
- A one-pot copper(II)-catalyzed tandem synthesis of 2-substituted pyrrolo[1,2-b]pyridazin-4(1H)-ones
-
A one-pot copper(II)-catalyzed tandem synthesis of 2-substituted pyrrolo[1,2-b]pyridazin-4(1H)-ones from N-aminopyrroles was developed. This tandem reaction involves a Conrad-Limpach-type reaction, including the thermal condensation of N-aminopyrroles with the carbonyl group of β-oxo esters followed by the cyclization of Schiff base intermediates. Compared to the traditional Conrad-Limpach quinoline synthesis, we herein successfully applied copper(II) as a catalyst in this transformation to furnish 2-substituted pyrrolo[1,2-b]pyridazin-4(1H)-ones for the first time. Most of the substrates bearing electron-donating (EDG) and electron-withdrawing (EWG) groups worked well with this procedure. The corresponding products could be converted directly into diverse pyrrolo[1,2-b]pyridazine for drug discovery and materials science. A copper(II)-catalyzed tandem synthesis of 2-substituted pyrrolo[1,2-b]pyridazin-4(1H)-ones from N-aminopyrroles was developed, and the corresponding products could be converted directly into diverse pyrrolo[1,2-b]pyridazine for drug discovery and materials science.
- Tan, Cun,Xiang, Haoyue,He, Qian,Yang, Chunhao
-
supporting information
p. 3656 - 3660
(2015/06/16)
-
- 1,5-Diketones Synthesis via Three-Component Cascade Reaction
-
A mild and efficient cascade synthesis of 1,5-diketones from readily available N,N-dicyclohexylmethylamine, 1,3-dicarbonyl compounds, and trifluoromethyl β-diketones has been developed. This cascade reaction occurs via an oxidation/Mannich reaction/Cope elimination/Michael addition/retro-Claisen reaction sequence, and provides multiple C-C bond formations in one pot. In addition, exquisite chemoselectivity is achieved in the reaction between 1,3-dicarbonyl compounds and trifluoromethyl β-diketones.
- Xing, Li-Juan,Lu, Tao,Fu, Wei-Li,Lou, Mei-Mei,Chen, Bo,Wang, Zhi-Shen,Jin, Yang,Li, Dan,Wang, Bin
-
supporting information
p. 3076 - 3080
(2015/11/03)
-
- One pot direct synthesis of β-ketoesters via carbonylation of aryl halides using cobalt carbonyl
-
A direct method for the synthesis of β-ketoesters from aryl halides (iodide, bromide) has been described by using cobalt carbonyl as carbon monoxide source in microwave irradiation. Using this protocol, a wide variety of substituted aryl halides has been successfully converted to corresponding β-ketoesters.
- Baburajan, Poongavanam,Elango, Kuppanagounder P.
-
supporting information
p. 3525 - 3528
(2014/06/10)
-
- Biocatalytic Synthesis of Enantiopure β-Methoxy-β-arylalanine Derivatives
-
Chiral β-hydroxy-β-arylalanine and β-methoxy-β-arylalanine derivatives, which occur widely in marine nature products, were stereoselectively synthesized with 99 % ee values. The two erythro isomers were prepared by L- or D-aminoacylase-catalyzed resolution of the corresponding N-acetyl derivatives, whereas the two threo isomers were obtained only by D-aminoacylase-catalyzed resolution of the derivatives. erythro-β-Hydroxy-β-arylalanine derivatives were prepared by diastereoselective hydrogenation of ethyl 2-(hydroxyimino)-3-oxo-3-arylpropanoates, which were in turn acquired by the oximation of ethyl 3-oxo-3-arylpropanoates with ethyl nitrite in the presence of nano-K2CO3 with yields of 72 % to 80 %. β-Methoxy-β-arylalanine derivatives were synthesized through Williamson reactions between the corresponding β-hydroxy-β-arylalanines and iodomethane with silver oxide as base.
- Fan, Shiming,Liu, Shouxin,Zhang, Hubo,Liu, Ying,Yang, Yihuang,Jin, Longyi
-
p. 5591 - 5597
(2014/10/15)
-
- Base initiated aromatization/CO bond formation: A new entry to O-pyrazole polyfluoroarylated ethers
-
A base initiated intermolecular SNAr reaction of pyrazolones with polyfluoroarenes was developed. The process involved the isomerization aromatization of pyrazolone followed by the CO bond formation via the selective CF bond cleavage. With this strategy, a wide range of O-pyrazole polyfluoroarylated ethers bearing diverse functional groups were synthesized in mild to good yields. Additionally, our method was also applied to the isoxazol substrates.
- Tang, Xiangyang,Chang, Jing,Liu, Cuibo,Zhang, Bin
-
supporting information
p. 6534 - 6537
(2015/01/08)
-
- THERAPEUTIC METHODS
-
The present invention features a method for the treatment of Hepatitis C in a human in need thereof comprising administering a compound of Formulas (II) or (IIB) described herein or a pharmaceutically acceptable salt thereof in combination with one or more alternative Hepatitis C therapeutic agents
- -
-
-
- BENZOFURAN COMPOUNDS FOR THE TREATMENT OF HEPATITIS C VIRUS INFECTIONS
-
The present invention features compounds of formula (I) and salts thereof, pharmaceutical compositions comprising said compounds, and uses of such compounds in treating or preventing viral infections, such as HCV infections, and diseases associated with such infections.
- -
-
Page/Page column 29
(2013/03/26)
-
- Tert-BuOK-Catalyzed condensation of ethyl diazoacetate to aldehydes and palladium-catalyzed 1,2-hydrogen migration for the synthesis of β-ketoesters under solvent-free conditions
-
A mild and convenient method for the condensation of ethyl diazoacetate (EDA) with aldehydes catalyzed by tert-BuOK under solvent-free conditions was developed. The corresponding α-diazo-β-hydroxy esters were further converted into β-ketoesters through palladium-catalyzed 1,2-hydrogen migration under neat conditions. The two-step transformation exemplifies a simple method for the efficient and green synthesis of β-ketoesters. The Royal Society of Chemistry 2013.
- Chen, Shufeng,Yuan, Fang,Zhao, Haiying,Li, Baoguo
-
p. 12616 - 12620
(2013/08/23)
-
- Novel photosensitized cyclization reactions of ethyl 3-amino-3-phenyl-2- propenoate derivatives to highly substituted pyrroles
-
Irradiation of nitrogen-saturated acetonitrile solutions containing ethyl 3-amino-3-phenyl-2-propenoate derivatives with the (Z)-configuration [(Z)- 1] and 10-methylacridinium perchlorate (MAP) at wavelengths longer than 340 nm afforded the corresponding pyrrole derivatives in good to high yields without exhibiting a profound effect related to the substituents. An analysis of the Stern-Volmer plots for the fluorescence quenching of MAP by (Z)-1 showed that this sensitizer fluorescence is efficiently quenched, and hence electron transfer is confirmed to be involved in the primary process of the MAPsensitized cyclization reactions of 1.
- Ishida, Yohsuke,Yoshida, Yuhki,Igarashi, Tetsutaro,Sakurai, Tadamitsu
-
p. 1691 - 1698
(2013/09/12)
-
- TEMPO-catalyzed aerobic oxygenation and nitrogenation of olefins via C=C double-bond cleavage
-
A novel TEMPO-catalyzed aerobic oxygenation and nitrogenation of hydrocarbons via C=C double-bond cleavage has been disclosed. The reaction employs molecular oxygen as the terminal oxidant and oxygen-atom source by metal-free catalysis under mild conditions. This method can be used for the preparation of industrially and pharmaceutically important N- and O-containing motifs, directly from simple and readily available hydrocarbons.
- Wang, Teng,Jiao, Ning
-
p. 11692 - 11695
(2013/09/02)
-
- COMPOUNDS
-
The present invention features compounds of formula (I): and salts thereof, pharmaceutical compositions comprising said compounds, and uses of such compounds in treating or preventing viral infections, such as HCV infections, and diseases associated with such infections.
- -
-
-
- One-pot synthesis of β-keto esters and preparation of 3-ketopalmitoyl-CoA
-
β-Keto esters were synthesized from acyl chlorides and sodium ethyl acetoacetate in EtOH using a simple one-pot, one-step' method. The deacetylation of α-acetyl β-keto ester to β-keto ester was performed simply, by heating the reaction mixture at reflux for 12 hours, without the addition of additional reagents (e.g., NHl, NH MeOH, or NaOH). One of the β-keto esters prepared using this method was ethyl 3-oxohexadecanoate, a key intermediate in the synthesis of 3-ketopalmitoyl coenzyme A (3-oxohexadecanoyl coenzyme A), a potential substrate of the biologically important enzyme 17β-hydroxysteroid dehydrogenase type 12. Georg Thieme Verlag Stuttgart ? New York.
- Ko?ak, Urban,Kova?, Andreja,Gobec, Stanislav
-
experimental part
p. 1609 - 1612
(2012/08/07)
-
- Mechanism and scope of the MnIII-initiated oxidation of β-ketocarbonyl compounds: Furan synthesis
-
Unless the MnIII-produced carbon-radical from β-ketocarbonyl compounds undergoes smooth intramolecular addition to alkenes, it traps molecular oxygen in the reaction medium to produce a peroxy radical, which reacts with the neighbouring carbonyl group to form 1,2-dioxetane. Thermal decomposition of 1,2-dioxetane completes the oxidation to produce α-oxo ester. This oxidation seems to be general at 50°C under aerobic conditions, and can be catalytic for MnIII in AcOH with ultrasonic irradiation. Thus, the development of a new synthetic method for diversely substituted furans has been accomplished based on a couple of the MnIII-initiated domino oxidation of β-ketocarbonyl compounds with a suitable α-allylic substitution. Copyright
- Wang, Chao,Li, Zhilong,Ju, Yeming,Koo, Sangho
-
p. 6976 - 6985
(2013/03/13)
-
- Enantioselective titanium(III)-catalyzed reductive cyclization of ketonitriles
-
Reduction, please! The title reaction affords ?-hydroxyketones, a common structural motif in biologically active natural products, in good yields and high enantioselectivities at room temperature. The commercially available ansa-titanocene 1 was found to be an efficient catalyst for this process, which presumably proceeds by addition of a ketyl radical to a nitrile.
- Streuff, Jan,Feurer, Markus,Bichovski, Plamen,Frey, Georg,Gellrich, Urs
-
supporting information; experimental part
p. 8661 - 8664
(2012/09/21)
-
- Discovery of a new class of protein farnesyltransferase inhibitors in the arylthiophene series
-
Screening of the ICSN chemical library led to the discovery of 3-(4-chlorophenyl)-4-cyano-5-thioalkylthiophene 2-carboxylic acids as potent farnesyltransferase inhibitors. Enzymatic kinetic studies showed that this original FTI series belongs to the CaaX
- Lethu, Sébastien,Ginisty, Maryon,Bosc, Damien,Dubois, Jo?lle
-
supporting information; experimental part
p. 6205 - 6208
(2010/03/24)
-
- DBU-catalyzed condensation of acyldiazomethanes to aldehydes in water and a new approach to ethyl β-hydroxy α-arylacrylates
-
DBU-catalyzed condensation of ethyl diazoacetate (EDA) with aldehydes in pure water afforded corresponding β-hydroxy α-diazo carbonyl compounds. The β-hydroxy group of the products was further converted into β-siloxy group. The Rh(II)-catalyzed reaction of the β-aryl β-siloxy α-diazo carbonyl compounds gave 1,2-aryl shift products predominantly. The three-step transformation constitutes an efficient synthesis of ethyl β-hydroxy α-arylacrylates.
- Xiao, Fengping,Liu, Yu,Wang, Jianbo
-
p. 1147 - 1149
(2007/10/03)
-
- A novel synthetic method for β-keto esters
-
A novel synthetic method for the preparation of β-keto esters has been developed. α-Phenylseleno acetate was treated with LDA to produce a selenium-stabilised carbanion, which reacted with aldehydes, followed by selenoxide syn-elimination, to give β-keto esters.
- Qian, Hao,Ge, Chunrong,Huang, Xian
-
p. 160 - 161
(2008/02/03)
-
- Substitution of acyl for acetyl with N-acylbenzotriazoles catalyzed by samarium triiodide
-
Catalyzed by samarium triiodide (SmI3), substitution of acyl with N-acylbenzotriazoles for acetyl in acetoacetic esters and acetylacetone proceeds smoothly under neutral conditions in open air, affording the corresponding β-keto esters and β-diketones in good yields. Copyright Taylor & Francis Group, LLC.
- Zou, Xuefei,Jia, Xiaofei,Wang, Xiaoxia,Xie, Guanqun
-
p. 1617 - 1625
(2008/02/01)
-
- Preparation of polystyrene-supported α-seleno acetate and application to solid-phase synthesis of β-keto esters
-
A novel polystyrene-supported α-seleno acetate has been developed. This novel resin was treated with LDA to produce a selenium-stabilized carbanion, which reacted with aldehydes, followed by selenoxide syn-elimination to give β-keto esters. Georg Thieme Verlag Stuttgart.
- Qian, Hao,Huang, Xian
-
p. 1547 - 1548
(2007/10/03)
-
- CuSO4-catalyzed diazo decomposition in water: a practical synthesis of β-keto esters
-
CuSO4 was found to be an efficient catalyst for the diazo decomposition of β-hydroxy α-diazoesters in water. 1,2-H shift occurred efficiently to give β-keto esters in high yields. No O-H bond insertion products were identified.
- Liao, Mingyi,Wang, Jianbo
-
p. 8859 - 8861
(2007/10/03)
-
- Diamine derivatives
-
A compound represented by the general formula (1): Q1-Q2-T0-N(R1)-Q3-N(R2)-T1-Q4??(1) wherein R1 and R2 are hydrogen atoms or the like; Q1 is a saturated or unsaturated, 5- or 6-membered cyclic hydrocarbon group which may be substituted, or the like; Q2 is a single bond or the like; Q3 is a group in which Q5 is an alkylene group having 1 to 8 carbon atoms, or the like; and T0 and T1 are carbonyl groups or the like; a salt thereof, a solvate thereof, or an N-oxide thereof. The compound is useful as an agent for preventing and/or treating cerebral infarction, cerebral embolism, myocardial infarction, angina pectoris, pulmonary infarction, pulmonary embolism, Buerger's disease, deep venous thrombosis, disseminated intravascular coagulation syndrome, thrombus formation after valve or joint replacement, thrombus formation and reocclusion after angioplasty, systemic inflammatory response syndrome (SIRS), multiple organ dysfunction syndrome (MODS), thrombus formation during extracorporeal circulation, or blood clotting upon blood drawing.
- -
-
-
- Niobium(V) chloride-catalyzed C-H insertion reactions of α-diazoesters: Synthesis of β-keto esters
-
Aldehydes react readily with ethyl diazoacetate in the presence of 5 mol% of NbCl5 in dichloromethane to produce the corresponding β-keto esters in good yields with high selectivity. This method is very useful for the preparation of β-keto esters from both electron-rich as well as electron-deficient aromatic aldehydes under mild reaction conditions.
- Yadav,Subba Reddy,Eeshwaraiah,Reddy
-
p. 875 - 878
(2007/10/03)
-
- DIAMINE DERIVATIVES
-
A compound represented by the general formula (1):Q1-Q2-T0-N(R1)-Q3-N(R2)-T1-Q4 wherein R1 and R2 are hydrogen atoms or the like; Q1 is a saturated or unsaturated, 5- or 6- membered cyclic hydrocarbon group which may be substituted, or the like; Q2 is a single bond or the like; Q3 is a group in which Q5 is an alkylene group having 1 to 8 carbon atoms, or the like; and T0 and T1 are carbonyl groups or the like; a salt thereof, a solvate thereof, or an N-oxide thereof. The compound is useful as an agent for preventing and/or treating cerebral infarction, cerebral embolism, myocardial infarction, angina pectoris, pulmonary infarction, pulmonary embolism, Buerger's disease, deep venous thrombosis, disseminated intravascular coagulation syndrome, thrombus formation after valve or joint replacement, thrombus formation and reocclusion after angioplasty, systemic inflammatory response syndrome (SIRS), multiple organ dysfunction syndrome (MODS), thrombus formation during extracorporeal circulation, or blood clotting upon blood drawing.
- -
-
-