- Epoxide-opening cascades triggered by a Nicholas reaction: Total synthesis of teurilene
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Natural inspiration: Based on the biosynthesis of squalene-derived polyethers, a total synthesis of teurilene is described. The carbocation formation in the Nicholas reaction serves to control the initiation of a polyepoxide ring-opening cascade. The three furan rings present in teurilene were obtained in excellent yield in one step. Boc=tert-butoxycarbonyl, TMS=trimethylsilyl. Copyright
- Rodríguez-L?pez, Julio,Pinacho Cris?stomo, Fernando,Ortega, Nuria,L?pez-Rodríguez, Matías,Martín, Víctor S.,Martín, Tomás
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- Radiosynthesis of tritium-labeled novel nitromethylene neonicotinoids compounds with NaB3H4
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Paichongding and Cycloxaprid are two novel neonicotinoids with good industrialization prospects for their high activity against imidacloprid- resistant pest. In this paper, the radiosynthesis of [3H 2]-Paichongding and [3H2]-Cycloxaprid was achieved using a NaB3H4 reduction. The title compounds were obtained with chemical purities of 98.7 and 98.4%, and radiochemical purities of 97.3 and 98.6%, respectively. The labeled compounds could be used as radiotracers for further study of metabolism and toxicology. Copyright
- Li, Chao,Xu, Xiao-Yong,Li, Ju-Ying,Ye, Qing-Fu,Li, Zhong
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- 2:2 condensation products from the reaction of N-substituted 1,2-diaminoethanes and 1,3-diaminopropanes with succinaldehyde and glutaraldehyde
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The reaction of N-substituted 1,2-diaminoethanes and 1,3-diaminopropanes (1) with succinaldehyde (2) and glutaraldehyde (9) in water gave the 2:2 condensation products (4 and 10).
- Okawara, Tadashi,Okamoto, Yoshinari,Ehara, Shuji,Yamasaki, Tetsuo,Furukawa, Mitsuru
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- Synthetic studies on amphidinolides C and F: synthesis of the C18-C29 segment of amphidinolide F
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The C18-C29 segment of amphidinolide F is synthesised in 12 steps from 1,4-butanediol. Key steps include a mono-Sharpless dihydroxylation of a dienoate, iodocyclisation to construct the trans-THF ring and an E-selective Wittig reaction to introduce the C25-C26 olefin.
- Armstrong, Alan,Pyrkotis, Constantina
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- Diastereoselective Synthesis of Cyclic Five-Membered trans,trans-Configured Nitrodiols by Double Henry Reaction of 1,4-Dialdehydes
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Conformationally constrained perhydroquinoxalines 4 show high κ receptor affinity, selectivity over related receptors and full agonistic activity. Since the κ affinity can be correlated with the dihedral angle of the ethylenediamine pharmacophore (4a: 55°/71°), the dihedral angles of the postulated cyclopentane derivative 5a (73°/84°) and indane derivative 6a (77°/81°) were calculated. The first step of the synthesis represents a double Henry reaction of 1,4-dialdehydes 8 and 10 with nitromethane, leading predominantly to the trans,trans-configured nitrodiols 9 and 11. X-ray crystal structure analyses of 9 and 11 led to dihedral angles O2N-C-C-OH of 73.4 and 88.3°, respectively, which reflect the calculated dihedral angles of the hypothesized final products 5a and 6a. Since κ receptor affinity can be correlated with the dihedral angle of ethylenediamine pharmacophores, the dihedral angles of the postulated cyclopentane derivative 5a (73°/84°) and indane derivative 6a (77°/81°) were calculated. X-ray crystal structure analyses of the synthesized compounds 9 and 11 led to dihedral angles of 73.4 and 88.3°, respectively, reflecting the calculated dihedral angles of the hypothesized final products 5a and 6a.
- Fr?hlich, Janine,Lehmkuhl, Kirstin,Fr?hlich, Roland,Wünsch, Bernhard
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- Seven-membered azabridged neonicotinoids: Synthesis, crystal structure, insecticidal assay, and molecular docking studies
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To study the influence of the ring sizes, 37 novel seven-membered azabridged neonicotinoid analogues were synthesized by reactions of nitromethylene analogues, succinaldehyde, and aniline hydrochlorides. Most of the title compounds presented higher insecticidal activities than that of imidacloprid (IMI), cycloxaprid (CYC), and eight-membered compounds against cowpea aphid (Aphis craccivora), armyworm (Pseudaletia separata Walker), and brown planthopper (Nilaparvata lugens), which indicated that introducing the structure of a seven-membered azabridge could significantly improve the insecticidal activities of neonicotinoid analogues. Docking study and binding mode analysis also revealed that introducing methyl group into position 2 of phenyl ring could increase the hydrophobic interactions with receptor, which implied that position 2 might be the key site to get high insecticidal compounds.
- Xu, Renbo,Luo, Ming,Xia, Rui,Meng, Xiaoqing,Xu, Xiaoyong,Xu, Zhiping,Cheng, Jiagao,Shao, Xusheng,Li, Houju,Li, Zhong
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- Reoptimization of the Organocatalyzed Double Aldol Domino Process to a Key Enal Intermediate and Its Application to the Total Synthesis of Δ12-Prostaglandin J3
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Re-investigation of the l-proline catalyzed double aldol cascade dimerization of succinaldehyde for the synthesis of a key bicyclic enal intermediate, pertinent in the field of stereoselective prostaglandin synthesis, is reported. The yield of this process has been more than doubled, from 14 % to a 29 % isolated yield on a multi-gram scale (32 % NMR yield), through conducting a detailed study of the reaction solvent, temperature, and concentration, as well as a catalyst screen. The synthetic utility of this enal intermediate has been further demonstrated through the total synthesis of Δ12-prostaglandin J3, a compound with known anti-leukemic properties.
- Pel?s, Andrejs,Gandhamsetty, Narasimhulu,Smith, James R.,Mailhol, Damien,Silvi, Mattia,Watson, Andrew J. A.,Perez-Powell, Isabel,Prévost, Sébastien,Schützenmeister, Nina,Moore, Peter R.,Aggarwal, Varinder K.
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- Novel small-molecule hybrid-antibacterial agents against s. Aureus and mrsa strains
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Ongoing resistance developments against antibiotics that also affect last-resort antibiotics require novel antibacterial compounds. Strategies to discover such novel structures have been dimerization or hybridization of known antibacterial agents. We found novel antibacterial agents by dimerization of indols and hybridization with carbazoles. They were obtained in a simple one-pot reaction as bisindole tetrahydrocarbazoles. Further oxidation led to bisindole carbazoles with varied substitutions of both the indole and the carbazole scaffold. Both the tetrahydrocarbazoles and the carbazoles have been evaluated in various S. aureus strains, including MRSA strains. Those 5-cyano substituted derivatives showed best activities as determined by MIC values. The tetrahydrocarbazoles partly exceed the activity of the carbazole compounds and thus the activity of the used standard antibiotics. Thus, promising lead compounds could be identified for further studies.
- Gehrmann, Robin,Hertlein, Tobias,Hilgeroth, Andreas,Hopke, Elisa,Lalk, Michael,Ohlsen, Knut
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- Total syntheses of hyperaspidinols A and B enabled by a bioinspired diastereoselective cascade sequence
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A bioinspired acid-triggered hemiacetalization/dehydration/[3 + 3]-type cycloaddition cascade process was disclosed, diastereoselectively furnishing furo[2,3-b]chromene skeleton under mild conditions. The viability of this approach was demonstrated by syntheses of a series of furo[2,3-b]chromene and pyrano[2,3-b]chromene derivatives. The successful total syntheses of two lignan-phloroglucinol hybrids, hyperaspidinols A and B, exemplified the synthetic utility of our biomimetic methodology.
- Chen, Huiyu,Lu, Xiuxiang,Tan, Haibo,Wang, Sasa,Zhang, Wenge,Zheng, Anquan,Zhou, Tingting
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- Degradation of gaseous unsymmetrical dimethylhydrazine by vacuum ultraviolet coupled with MnO2
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In this study, α-, β-, and δ-MnO2 were prepared by a uniform hydrothermal method and then coupled with vacuum ultraviolet (VUV) for the degradation of gaseous unsymmetrical dimethylhydrazine (UDMH). The performance in the removal of UDMH, by-product distribution and mechanism were systematically investigated. The catalysts were characterized by X-ray diffraction (XRD), N2 adsorption/desorption, Field Emission Scanning Electron Microscopy (FE-SEM), Raman, thermogravimetry (TG), Fourier-transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) to investigate the factors affecting the catalytic activity. The results showed that O2 and H2O were essential for the removal of UDMH. Photooxidation and ozone catalytic oxidation contribute to the removal and mineralization of UDMH. The integrated process considerably improved the removal and mineralization of UDMH by ozone catalytic oxidation. More reactive oxygen species were generated in the integrated process. The catalytic activity of the prepared catalysts follows the order: δ-MnO2 > α-MnO2 > β-MnO2. δ-MnO2 displayed the highest removal rate of 100% and a CO2 concentration of 42 ppmv. The good performance of δ-MnO2 was mainly attributed to the large number of surface oxygen vacancies.
- Huang, Yuanzheng,Jia, Ying,Shen, Keke,Hou, Ruomeng,Zhang, Yongyong,Hou, Li'an
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supporting information
p. 1194 - 1202
(2021/02/06)
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- TiO2-reduced graphene oxide for the removal of gas-phase unsymmetrical dimethylhydrazine
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Unsymmetrical dimethylhydrazine (UDMH) contaminated waste gas and related intermediates pose a great threat to human health. TiO2-reduced graphene oxide aerogel (rGA) samples with different graphene content levels were synthetized and characterized for the degradation of UDMH. The effects of GO content, humidity, and temperature were investigated under UV and VUV light, with highest UDMH conversion values of 68% and 95%, respectively. Compared with pure TiO2, the enhanced degradation activity of TiO2-rGA under UV light can be attributed to a synergetic effect between absorption and photocatalysis, while the high UDMH conversion under VUV light relies on photolysis and ozonation. The high oxygen-containing group content, rather than a high SSA, and electron trapping by graphene are key factors determining the outstanding performance of TiO2-rGA with 80 mg of GO. The prepared TiO2-graphene aerogels are promising for the degradation of gas-phase UDMH. This journal is
- Ruomeng, Hou,Ying, Jia,Yuanzheng, Huang,Keke, Shen,Huixin, Zhu
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p. 394 - 402
(2021/01/11)
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- Direct catalytic synthesis of β-(C3)-substituted pyrroles: A complementary addition to the Paal-Knorr reaction
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The synthesis of β-(C3)-functionalized pyrroles is a challenging task and requires a multistep protocol. An operationally simple direct catalytic synthesis of β-substituted pyrroles has been developed. This one-pot multicomponent method combined aqueous succinaldehyde as 1,4-dicarbonyl, primary amines, and isatins to access hydroxyl-oxindole β-tethered pyrroles. Direct synthesis of the β-substituted free NH-pyrrole is the central intensity of this work. DFT-calculations and preliminary mechanism investigation support the possible reaction pathway. This journal is
- Pawar, Amol Prakash,Yadav, Jyothi,Mir, Nisar Ahmad,Iype, Eldhose,Rangan, Krishnan,Anthal, Sumati,Kant, Rajni,Kumar, Indresh
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supporting information
p. 251 - 254
(2021/01/13)
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- The structure modification of seven-membered aza-brigded neonicotinoids in order to investigate their impact on honey bees
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In order to explore the relationship between the structure and the toxicity to honey bees of seven-membered aza-bridged neonicotinoids, 16 novel seven-membered aza-bridged neonicotinoid analogues are synthesized by replacing the pyridine ring, and changing the substituents on the pyridine ring, the electron-withdrawing group NO2 and the imidazole ring of our previously developed aza-bridged neonicotinoid 1-[(6-chloropyridin-3-yl)methyl)]-10-(2,5-dimethylphenyl)-9-nitro-2,3,5,6,7,8-hexahydro-1H-5,8-epiminoimidazo azepine (C-29). The insecticidal bioactivities against cowpea aphid (Aphis craccivora) and the bee toxicities of these compounds are tested. Some of the title compounds present good insecticidal activities against cowpea aphid. The results also show that some of the title compounds exhibit lower bee toxicity than that of C-29 and imidacloprid. This suggests that changing the substituents on the neonicotinoids can influence the toxicity toward honey bees of these analogues.
- Cao, Xiaofeng,Chen, Xi,Chen, Yuce,Li, Zhong,Xu, Xiaoyong
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p. 835 - 844
(2021/05/29)
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- Converging conversion - using promiscuous biocatalysts for the cell-free synthesis of chemicals from heterogeneous biomass
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Production of chemicals from lignocellulosic biomass has been proposed as a suitable replacement to petrochemicals. However, one inherent challenge of biomass utilization is the heterogeneity of the substrate resulting in the presence of mixed sugars after hydrolysis. Fermentation of mixed sugars often leads to poor yield and generation of multiple by-products, thus complicating the subsequent downstream processing. System biocatalysis has thus been developed in recent years to address this challenge. In this work, several novel enzymes with broad substrate promiscuity were identified using a sequence-based discovery approach as suitable biocatalysts in a conversion ofd-xylose andl-arabinose, two major constituents of hemicellulose found in plant biomass. These promiscuous enzymes enabled simultaneous biotransformation ofd-xylose andl-arabinose to yield 1,4-butanediol (BDO) with a maximum production rate of 3 g L?1h?1and a yield of >95%. This model system was further adapted toward the production of α-ketoglutarate (2-KG) from the pentoses using O2as a cosubstrate for cofactor recycling reaching a maximum production rate of 4.2 g L?1h?1and a yield of 99%. To verify the potential applicability of our system, we attempted to scale up the BDO and 2-KG production fromd-xylose andl-arabinose. Simple optimization and reaction engineering allowed us to obtain BDO and 2-KG titers of 18 g L?1and 42 g L?1, with theoretical yields of >75% and >99%, respectively. One of the promiscuous enzymes identified together with auxiliary promiscuous enzymes was also suitable for stereoconvergent synthesis from a mixture ofd-glucose andd-galactose, predominant sugars found in food waste streams and microalgae biomass.
- Pick, André,Sieber, Volker,Sutiono, Samuel
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supporting information
p. 3656 - 3663
(2021/06/06)
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- Novel method for synthesizing dialdehyde compound
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The invention provides a method for synthesizing a dialdehyde compound, and an acetal represented by the structural formula (I) and a Grignard reagent represented by the structural formula (II) are subjected to a coupling reaction and then hydrolyzed to obtain the dialdehyde compound, wherein the structural formula (I) and the structural formula (II) are described in the specification. The method has the advantages of high reaction activity, the reaction can be carried out even under the condition of room temperature, the reaction completed time is short, almost no other by-products are generated, no catalyst is required to be used, the reaction yield is high, and the reaction speed is fast. Moreover, the product purity is high, the dialdehyde compound with the purity of about 98% can be obtained after concentration, and no complex purification process is required.
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Paragraph 0057; 0059; 0061
(2020/07/23)
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- Solvent Free Synthesis of N-Substituted Pyrroles Catalyzed by Calcium Nitrate
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Moderated and mild way for synthesizing N-substituted pyrrole has been demonstrated herein. No solvents need to be used for this reaction, and instead, reactants themselves acted as a reaction medium. In fact, the reaction is carried out using catalytic amount of Ca(NO3)2.4H2O. The reaction conditions are selective and mild that helped to tolerate a wide variety of functional groups to give the desired products in good chemical yields.
- Wani, Rucha R.,Chaudhari, Hemchandra K.,Takale, Balaram S.
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p. 1337 - 1340
(2019/02/05)
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- Synthesis method of dinotefuran
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The invention discloses a synthesis method of dinotefuran. The synthesis method comprises the following steps that furan serves as a starting raw material and is subjected to oxidation ring opening togenerate 1,4-butenedial, 1,4-butenedial and nitromethane are subjected to Michael addition, metal borohydride reduction and cyclizing, nitromethyl is converted into aldehyde groups to obtain tetrahydrofuran-3-formaldehyde, then tetrahydrofuran-3-formaldehyde and 1,5-dimethyl-2-nitroiminohexahydro-1,3,5-triazine are subjected to condensation and reduction, and finally dinotefuran is obtained through hydrolysis. According to the method, the raw materials are easy to obtain, reaction conditions are mild, the yield is relatively high, and the method is suitable for large-scale production.
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Paragraph 0034; 0039-0041
(2019/11/20)
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- 2,3-Butanediol dehydration catalyzed by silica-supported alkali phosphates
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Characterization of acid-base centers and catalytic dehydration of 2,3-butanediol (BDO) was performed over a wide range of silica-supported alkali phosphates (M_P/SiO2; M = Na, K, Cs; M:P = 0.5–3 mol:mol). Selectivity to 1,3-butadiene (BD) and 3-butene-2-ol (3B2OL) formed by elimination correlates with the densities of conjugated acid-base pairs and increases in the order Na ??M+ moieties. Isolated Br?nsted acid centers are probably silica grafted phosphoric acid molecules at low M/P and –PO(OH)2 end groups of oligophosphates at M/P > 1.5. Deactivation rate increases with the increase of M/P ratio in order Na K Cs. Deactivation patterns imply that sites responsible for elimination are active in dehydrative epoxidation. Dehydration of 3B2OL smoothly proceeds to BD, but the catalysts deactivate faster compared to BDO dehydration.
- Kim, Wooyoung,Shin, Wookyun,Lee, Kyoung Jun,Cho, YongSeok,Kim, Hyung Soon,Filimonov, Igor N.
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p. 148 - 163
(2018/11/26)
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- Selective mono addition of aryllithiums to dialdehydes by micromixing
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Micromixing enables highly selective mono addition of aryllithiums to dialdehydes. Because the unchanged formyl group in the products can be used for further transformations, the present approach serves as a powerful method for protecting-group-free synthesis.
- Nagaki, Aiichiro,Yamashita, Hiroki,Takahashi, Yusuke,Ishiuchi, Satoshi,Imai, Keita,Yoshida, Jun-Ichi
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supporting information
p. 71 - 73
(2018/01/26)
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- Synthesis and biological investigations of 3β-aminotropane arylamide derivatives with atypical antipsychotic profile
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This work is a continuation of our previous research, concentrating this time on lead structure modification to increase the 5-HT1A receptor affinity and water solubility of designed compounds. Therefore, the compounds synthesised within the present project included structural analogues of 3β-acylamine derivatives of tropane with the introduction of a methyl substituent in the benzyl ring and a 2-quinoline, 3-quinoline, or 6-quinoline moiety. A series of novel 3β-aminotropane derivatives was evaluated for their affinity for 5-HT1A, 5-HT2A, and D2 receptors, which allowed for the identification of compounds 12e, 12i, and 19a as ligands with highest affinity for the tested receptors; they were then subjected to further evaluation in preliminary in vivo studies. Selected compounds 12i and 19a displayed antipsychotic properties in the d-amphetamine-induced and MK-801-induced hyperlocomotor activity test in mice. Moreover, compound 19a showed significant antidepressant-like activity in the forced swim test in mice.
- Stefanowicz, Jacek,S?owiński, Tomasz,Wróbel, Martyna Z.,?lifirski, Grzegorz,Dawidowski, Maciej,Stefanowicz, Zdzis?awa,Jastrz?bska-Wi?sek, Magdalena,Partyka, Anna,Weso?owska, Anna,Tur?o, Jadwiga
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p. 1906 - 1928
(2018/06/26)
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- Cobicistat midbody and preparation method thereof
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The invention provides a preparation method of a Cobicistat midbody. The preparation method includes: oxidizing a compound 3 to obtain a compound 4 and allowing the compound 4 to be condensated with (S)-tert-butanesulfinamide in the absence of a dehydrating agent to obtain a compound 5; subjecting the compound 5 to nucleophilic addition to obtain a compound 6; subjecting the compound 6 to hydration and dissolution to obtain a compound 2.
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Paragraph 0039-0040
(2018/04/01)
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- Novel Tetraindoles and Unexpected Cycloalkane Indoles from the Reaction of Indoles and Aliphatic Dialdehydes
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The reaction of indoles with dialdehydes was studied for the first time. Mild reaction conditions using glacial acetic acid led to two novel kinds of reaction products: one designated as alkyl chain-connected tetraindoles and the other one as bis(indolyl)-substituted cycloalkane indoles. The suggested reaction pathways are discussed. The indole substituents of the cycloalkane indoles were either trans or cis orientated depending from the alkyl chain length.
- El-Sayed, Mardia Telep,Mahmoud, Kazem Ahmed,Heinemann, Frank W.,Hilgeroth, Andreas
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p. 714 - 719
(2017/02/03)
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- The asymmetric synthesis of enantiopure C(5)-substituted transpentacins via diastereoselective conjugate additions to a β′-amino-α,β-unsaturated ester
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The asymmetric synthesis of a range of 1,2-anti-1,5-syn-transpentacins, bearing either alkyl, phenyl or hydroxymethyl substituents at the C(5)-position, has been achieved using the diastereoselective conjugate additions of Grignard reagents to an enantiopure β′-amino-α,β-unsaturated ester as the key step. In addition, the doubly diastereoselective conjugate addition of an enantiopure lithium amide reagent to the β′-amino-α,β-unsaturated ester provided access to the corresponding β,β′-diamino ester, which was subsequently converted to both (S,S)-(2,5-diaminocyclopent-1-yl)methanol and (S,S)-2,5-diaminocyclopentane-1-carboxylic acid. In each case, the final enantiopure products were obtained as single diastereoisomers (>99:1 dr) in good yields over five steps or fewer from commercially available starting materials.
- Davies, Stephen G.,Fletcher, Ai M.,Roberts, Paul M.,Thomson, James E.,Zammit, Charlotte M.
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p. 208 - 221
(2020/01/31)
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- Compound And Method
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A compound of formula (I): (I) wherein Y is, Z is OR10, NR11R11 SR11, S(0)R11 S02R11, R10 is H, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted heterocyclyl, CO—R11, or a protecting group, and R11 is optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted heterocyclyl, or alkoxyl; a process for making a compound of formula (I); and a process for making a prostaglandin or a prostaglandin analogue using a compound of formula (I). wherein Y is
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Paragraph 0211-0216
(2015/06/17)
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- Synthesis of prostaglandin analogues, latanoprost and bimatoprost, using organocatalysis via a key bicyclic enal intermediate
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Two antiglaucoma drugs, bimatoprost and latanoprost, which are analogues of the prostaglandin, PGF2?±, have been synthesized in just 7 and 8 steps, respectively. The syntheses employ an organocatalytic aldol reaction that converts succinaldehyde into a key bicyclic enal intermediate, which is primed for attachment of the required lower and upper side chains. By utilizing the crystalline lactone, the drug molecules were prepared in >99% ee.
- Pr??vost, S??bastien,Thai, Karen,Sch??tzenmeister, Nina,Coulthard, Graeme,Erb, William,Aggarwal, Varinder K.
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supporting information
p. 504 - 507
(2015/03/05)
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- Asymmetric Formal [3+2] Cycloaddition Reaction of Succinaldehyde and Nitroalkene Catalyzed by Diphenylprolinol Silyl Ether
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The enantioselective domino Michael/Henry reaction of nitroalkenes with succinaldehyde was found to proceed efficiently upon using diphenylprolinol silyl ether as the organocatalyst. The reaction affords cis-disubstituted nitropentenes with excellent diastereoselectivities and enantioselectivities after treatment of the Michael product with Ac2O and pyridine. cis-Disubstituted nitropentenes are obtained with excellent diastereoselectivities and enantioselectivities by a formal [3+2] cycloaddition reaction. The first reaction is a domino reaction composed of the diphenylprolinol silyl ether mediated Michael reaction of nitroalkene with succinaldehyde followed by a Henry reaction. The next reaction is a dehydration achieved by using Ac2O and pyridine.
- Umemiya, Shigenobu,Hayashi, Yujiro
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p. 4320 - 4324
(2015/07/27)
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- Proline-Catalyzed Knoevenagel Condensation/[4+2] Cycloaddition Cascade Reaction: Application to Formal Synthesis of Averufin
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A remarkable proline-catalyzed method for the construction of biologically interesting oxygen-bridged tricyclic ketal skeletons was uncovered by starting from a variety of readily available cyclic 1,3-diketones and either 1,4- or 1,5-dicarbonyl substrates. The approach, which mimics a biosynthetic Knoevenagel condensation/[4+2] cycloaddition sequence, establishes a viable synthetic strategy for the efficient formal synthesis of averufin. A remarkable proline-catalyzed Knoevenagel condensation/[4+2] cycloaddition cascade reaction was uncovered for the construction of biologically interesting tricyclic ketal skeletons. This approach mimics a biosynthetic sequence and establishes a viable synthetic strategy for the efficient formal synthesis of averufin.
- Tan, Haibo,Chen, Xinzheng,Chen, Huiyu,Liu, Hongxin,Qiu, Shengxiang
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supporting information
p. 4956 - 4963
(2015/08/03)
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- Efficient and Selective Cu/Nitroxyl-Catalyzed Methods for Aerobic Oxidative Lactonization of Diols
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Cu/nitroxyl catalysts have been identified that promote highly efficient and selective aerobic oxidative lactonization of diols under mild reaction conditions using ambient air as the oxidant. The chemo- and regioselectivity of the reaction may be tuned by changing the identity of the nitroxyl cocatalyst. A Cu/ABNO catalyst system (ABNO = 9-azabicyclo[3.3.1]nonan-N-oxyl) shows excellent reactivity with symmetrical diols and hindered unsymmetrical diols, whereas a Cu/TEMPO catalyst system (TEMPO = 2,2,6,6-tetramethyl-1-piperidinyl-N-oxyl) displays excellent chemo- and regioselectivity for the oxidation of less hindered unsymmetrical diols. These catalyst systems are compatible with all classes of alcohols (benzylic, allylic, aliphatic), mediate efficient lactonization of 1,4-, 1,5-, and some 1,6-diols, and tolerate diverse functional groups, including alkenes, heterocycles, and other heteroatom-containing groups.
- Xie, Xiaomin,Stahl, Shannon S.
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supporting information
p. 3767 - 3770
(2015/04/14)
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- ACYCLIC ALKENES VIA OZONOLYSIS OF MULTI-UNSATURATED CYCLOALKENES
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A method of making a compound of formula (IIa) by selective ozonolysis of a compound of formula (I) is provided, wherein A is a C6-C10 alkene chain with at least one double bond, R1 is a C1-C10 alkyl, and R3 is an oxygen-containing functional group.
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Paragraph 00154-00155
(2015/02/02)
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- Hypervalent iodine/TEMPO-mediated oxidation in flow systems: A fast and efficient protocol for alcohol oxidation
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Hypervalent iodine(III)/TEMPO-mediated oxidation of various aliphatic, aromatic and allylic alcohols to their corresponding carbonyl compounds was successfully achieved by using microreactor technology. This method can be used as an alternative for the oxidation of various alcohols achieving excellent yields and selectivities in significantly shortened reaction times.
- Ambreen, Nida,Kumar, Ravi,Wirth, Thomas
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p. 1437 - 1442
(2013/08/23)
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- Synthesis and Biological Evaluation of Tricyclic Guanidine Analogues of Batzelladine K for Antimalarial, Antileishmanial, Antibacterial, Antifungal, and Anti-HIV Activities
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Fifty analogues of batzelladine K were synthesized and evaluated for in vitro antimalarial (Plasmodium falciparum), antileishmanial (Leishmania donovani), antimicrobial (panel of bacteria and fungi), antiviral (HIV-1) activities. Analogues 14h and 20l exhibited potential antimalarial activity against chloroquine-sensitive D6 strain with IC50 1.25 and 0.88μm and chloroquine-resistant W2 strain with IC50 1.64 and 1.07μm, respectively. Analogues 12c and 14c having nonyl substitution showed the most potent antileishmanial activity with IC50 2.39 and 2.78μm and IC90 11.27 and 12.76μm, respectively. Three analogues 12c, 14c, and 14i were the most active against various pathogenic bacteria and fungi with IC503.02μm and MIC/MBC/MFC 6μm. Analogue 20l having pentyl and methyl substituents on tricycle showed promising activities against all pathogens. However, none was found active against HIV-1. Our study demonstrated that the tricyclic guanidine compounds provide new structural class for broad spectrum activity. Fifty analogues of tricyclic guanidine derivative of batzelladine K were synthesized and tested for antimalarial, antileishmanial, antimicrobial, antifungal and anti-HIV activities. We have identified several active analogues.
- Ahmed, Nafees,Brahmbhatt, Keyur G.,Khan, Shabana I.,Jacob, Melissa,Tekwani, Babu L.,Sabde, Sudeep,Mitra, Debashis,Singh, Inder P.,Khan, Ikhlas A.,Bhutani, Kamlesh K.
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p. 491 - 498
(2013/05/21)
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- COMPOUND AND METHOD
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A compound of formula (I): (I) wherein Y is, Z is OR10, NR11R11 SR11, S(0)R11 S02R11, R10 is H, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted heterocyclyl, CO-R11, or a protecting group, and R11 is optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted heterocyclyl, or alkoxyl; a process for making a compound of formula (I); and a process for making a prostaglandin or a prostaglandin analogue using a compound of formula (I).
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Page/Page column 36; 37; 59
(2014/01/08)
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- A catalytic enantioselective tandem allylation strategy for rapid terpene construction: Application to the synthesis of pumilaside aglycon
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Catalytic enantioselective 1,2-diboration of 1,3-dienes followed by cascade allylborations with dicarbonyls provides rapid entry into carbocyclic reaction products. The stereochemical course of this reaction was studied along with its application in the synthesis of pumilaside aglycon.
- Ferris, Grace E.,Hong, Kai,Roundtree, Ian A.,Morken, James P.
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supporting information
p. 2501 - 2504
(2013/03/29)
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- Pot economy in the synthesis of prostaglandin A1 and E 1 methyl esters
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Pot luck: Prostaglandins regulate a broad range of physiological processes and some of their derivatives are used as effective drugs, but previously their preparation has required many steps. The title compounds were efficiently synthesized in a small number of synthetic steps by using a recently developed organocatalyst and practical, one-pot operations involving several successive reactions.
- Hayashi, Yujiro,Umemiya, Shigenobu
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supporting information
p. 3450 - 3452
(2013/05/08)
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- Asymmetric domino double michael addition of nitroolefins and aldehyde esters with trans-perhydroindolic acid as an organocatalyst
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An asymmetric domino double Michael addition reaction was developed using accessible substrates to construct biologically important and synthetically challenging cyclopentanes with four contiguous stereocenters. The proline-like molecules, trans-perhydroindolic acids, proved to be efficient organocatalysts in this reaction. Under the optimal reaction conditions, the asymmetric domino double Michael addition provided good yields (up to 98%), and excellent diastereoselectivities (up to 100% dr) and enantioselectivities (up to 99% ee). The obtained polysubstituted aliphatic cyclopentanes not only exist in biologically active natural products and medicines, but can also be converted into many other useful scaffolds via a simple transformation, such as cis-fused bicyclic lactams. Our current methodology is suitable for the synthesis of polysubstituted aliphatic cyclopentanes with contiguous multiple stereocenters. Georg Thieme Verlag Stuttgart. New York.
- An, Qianjin,Shen, Jiefeng,Butt, Nicholas,Liu, Delong,Liu, Yangang,Zhang, Wanbin
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supporting information
p. 1612 - 1622
(2013/07/27)
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- Characterization of a new enzyme oxidizing ω-amino group of aminocarboxyric acid, aminoalcohols and amines from Phialemonium sp. AIU 274
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A new enzyme exhibiting oxidase activity for ω-aminocarboxylic acids, ω-aminoalcohols, monoamines and diamines was found from a newly isolated fungal strain, Phialemonium sp. AIU 274. The enzyme also oxidized aromatic amines, but not l- and d-amino acids. The Vmax/Km value for hexylamine was higher than those for 6-aminoalcohol and 6-aminhexanoic acid in the aliphatic C6 substrates. In the aliphatic amines, the higher Vmax/Km values were obtained by the longer carbon chain amines. Thus, the enzyme catalyzed oxidative deamination of the ω-amino group in a wide variety of the ω-amino compounds and preferred medium- and long-chain substrates. The oxidase with such broad substrate specificity was first reported here. The enzyme contained copper, and the enzyme activity was strongly inhibited by isoniazid, iproniazid and semicarbazide, but not by clorgyline and pargyline. The enzyme was composed of two identical subunits of 75 kDa.
- Isobe, Kimiyasu,Sasaki, Tomoko,Aigami, Yuusuke,Yamada, Miwa,Kishino, Shigenobu,Ogawa, Jun
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- DIVALENT AND OXABRIDGED HETEROCYCLIC NEONICOTINOID COMPOUNDS AND PREPARATION METHODS THEREOF
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Nitromethylene analogues of imidacloprid and divalent and oxabridged heterocyclic neonicotinoid compounds constructed by dialdehydes, preparation methods and uses thereof are disclosed. Compounds represented by formula (A) or (B), their optical isomers or agrochemically acceptable salts are provided. Agrochemical compositions comprising the said compounds, their optical isomers or agrochemically acceptable salts, the uses of the said agrochemical compositions and the preparation methods of the said compounds, their optical isomers or agrochemically acceptable salts are also disclosed. The compounds and their derivatives have high insecticidal activities to several farming and forestry pests including homoptera and lepidoptera pests, such as aphis, fulgorid, whitefly, leafhopper, common thrips, cotton bollworm, cabbage caterpillar, cabbage moth, cotton leafworm and armyworm.
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Page/Page column 8-9
(2012/10/08)
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- DIVALENT AND OXABRIDGED HETEROCYCLIC NEONICOTINOID COMPOUNDS AND PREPARATION METHODS THEREOF
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Nitromethylene analogues of imidacloprid and divalent and oxabridged heterocyclic neonicotinoid compounds constructed by dialdehydes, preparation methods and uses thereof are disclosed. Compounds represented by formula (A) or (B), their optical isomers or agrochemically acceptable salts are provided. Agrochemical compositions comprising the said compounds, their optical isomers or agrochemically acceptable salts, the uses of the said agrochemical compositions and the preparation methods of the said compounds, their optical isomers or agrochemically acceptable salts are also disclosed. The compounds and their derivatives have high insecticidal activities to several farming and forestry pests including homoptera and lepidoptera pests, such as aphis, fulgorid, whitefly, leafhopper, common thrips, cotton bollworm, cabbage caterpillar, cabbage moth, cotton leafworm and armyworm.
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Page/Page column 10
(2012/11/06)
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- Stereocontrolled organocatalytic synthesis of prostaglandin PGF 2α in seven steps
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Prostaglandins are hormone-like chemical messengers that regulate a broad range of physiological activities, including blood circulation, digestion and reproduction. Their biological activities and their complex molecular architectures have made prostaglandins popular targets for synthetic organic chemists for over 40 years. Prostaglandin analogues are widely used as pharmaceuticals and some, such as latanoprost, which is used to treat glaucoma, have become billion-dollar drugs. Previously reported syntheses of these compounds are quite lengthy, and every chemical step costs time and energy, generates waste and is accompanied by material losses. Using a new bond disconnection, here we report a concise synthesis of the most complex prostaglandin, PGF 2α, with high levels of control of relative and absolute stereochemistry, and fewer steps. The key step is an aldol cascade reaction of succinaldehyde using proline organocatalysis to create a bicyclic enal in one step and an enantiomeric excess of 98%. This intermediate bicyclic enal is fully primed with the appropriate functionality for attachment of the remaining groups. Access to this bicyclic enal will not only render existing prostaglandin-based drugs more affordable, but will also facilitate the rapid exploration of related chemical structures around the ubiquitous five-membered ring motif, such as potentially therapeutic prostaglandin analogues.
- Coulthard, Graeme,Erb, William,Aggarwal, Varinder K.
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p. 278 - 281,4
(2020/07/31)
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- Solvent-free double aza-Michael under ultrasound irradiation: Diastereoselective sequential one-pot synthesis of pyrrolidine Lobelia alkaloids analogues
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Novel 2,5-meso-pyrrolidines have been straightforwardly synthesized from readily available symmetrical double Michael acceptors. The key step rested on an aza-Michael addition of primary alkylamines to bis-enones. Competitive Rauhut-Currier and aza-Michael reactions have been highlighted in protic solvent. Ultrasound activation associated with solvent-free conditions led to the expected pyrrolidines in quantitative yields and excellent stereoselectivities. The optimized conditions have been extended to the sonochemical synthesis of pyrrolidine Lobelia alkaloids analogues in short sequences.
- Amara, Zacharias,Drège, Emmanuelle,Troufflard, Claire,Retailleau, Pascal,Joseph, Delphine
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scheme or table
p. 7148 - 7157
(2012/10/08)
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- Stereoselective synthesis and structure-affinity relationships of bicyclic κ receptor agonists
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Reductive amination of the bicyclic ketone 4 led diastereoselectively to end-configured amines, which were transformed into the amides 7-10. The synthesis of the diastereomers 25 with an exo-configured amino moiety at position 6 was only successful after deactivation of both N-atoms of the 1,4-diazabicyclo[3.3.1]nonane system. The N-1-oxide 19 with an N-4-tosyl moiety was the crucial intermediate, which allows SN2 substitution with NaN3 under inversion of the configuration at position 6. Whereas the endo-configured pyrrolidine 7a (WMS-1302) revealed a κ receptor affinity of 73 nM, the exo-configured diastereomer 25a was almost inactive at the κ receptor (Ki > 1 μM). Replacement of the 3,4- dichlorophenylacetyl residue by other acyl and sulfonyl residues showed that it is essential for high κ affinity. The κ receptor affinities of the conformationally constrained pyrrolidines 7a and 25a were correlated with the dihedral angle N(pyrrolidine)-C-C-N(acetamide). A systematic conformational analysis of the potent but flexible κ agonist 2 showed that a dihedral angle of 168° (as in 25a) is energetically more disfavored than a dihedral angle of 58° (7a). However, even the conformation with a dihedral angle of 58° does not represent an energy minimum, which might explain the reduced K affinity of 7a. The Royal Society of Chemistry 2010.
- Kracht, Daniel,Rack, Elisabeth,Schepmann, Dirk,Froehlich, Roland,Wuensch, Bernhard
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scheme or table
p. 212 - 225
(2010/04/26)
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- Total synthesis of (±)-batzelladine K: A biomimetic approach
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Total synthesis of batzelladine K was achieved by a biomimetic approach. The key reactions involve two Wittig reactions of phosphoranes and aldehydes leading to an ,-unsaturated ketone, followed by a condensation with guanidine. The synthesis was accomplished in four steps with an overall yield of 12%. The relative stereochemistry of batzelladine K was established by NOE experiments and comparison with literature values. Georg Thieme Verlag Stuttgart - New York.
- Ahmed, Nafees,Brahmbhatt, Keyur G.,Singh, Inder Pal,Bhutani, Kamlesh K.
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body text
p. 2567 - 2570
(2010/09/10)
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- Method for synthesizing 2-carbomethoxytropinone
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Disclosed is a method of making (?)-cocaine efficient for use on a large scale. The cocaine is created by reacting an aqueous solution of (+)-2-carbomethoxytropinone (2-CMT) bitartrate, sodium amalgam and an acid that forms a highly soluble sodium salt to form (?)-methylecgonine. (?)-Methylecgonine is converted into (?)-cocaine. Sodium amalgam is continuously supplied from an electrolyzing unit to a reactor containing the aqueous solution of (+)-2-carbomethoxytropinone bitartrate and spent amalgam is continuously removed and regenerated. The aqueous solution is prepared by adding (rac)-2-CMT in chloroform to a solution of (+)-tartaric acid in water to create an aqueous phase having diastereomeric salts of 2-CMT with (+)-tartaric acid. An organic solvent is added to the aqueous phase and the crystals obtained from the combined aqueous phase and organic solvent are dried to obtain substantially pure crystalline (+)-2-carbomethoxytropinone bitartrate. The (rac)-2-CMT in chloroform is prepared by extracting 2-CMT from a citric acid solution.
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Page/Page column 8
(2010/12/31)
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- Divalent and oxabridged neonicotinoids constructed by dialdehydes and nitromethylene analogues of imidacloprid: Design, synthesis, crystal structure, and insecticidal activities
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A series of divalent and oxabridged neonicotinoids were synthesized by reactions of nitromethylene analogues of imidacloprid and dialdehydes, and their structures were confirmed by 1H NMR, 13C NMR, high-resolution mass spectroscopy, and X-ray diffraction analysis. The bioassays indicated that some of them were endowed with excellent insecticidal activities against cowpea aphid (Aphis craccivora), armyworm (Pseudaletia separata Walker), and brown planthopper (Nllaparvata lugens). Divalent neonicotinoid 6 and oxabridged 8a had higher activities than imidacloprid against cowpea aphids and armyworm; furthermore, the activity of 8a was 40.4-fold higher than that of imidacloprid against imidacloprid-resistant brown planthopper.
- Shao, Xusheng,Hua,Xiaoyong,Xinglei,Zewen,Zhong,Qian, Xuhong
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experimental part
p. 2696 - 2702
(2011/08/05)
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- Sequential Mannich-aza-Michael reactions for the stereodivergent synthesis of highly substituted pyrrolidines
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A stereodivergent synthesis of 2,3,5-trisubstituted pyrrolidines by an organocatalytic Mannich/aza-Michael addition sequence has been developed. Depending upon the choice of the base used in the intramolecular aza-Michael additions, 2,5-trans- or 2,5-cis-configured pyrrolidines were obtained in high yields and excellent diastereomeric ratios. Selective deprotection of the amino group and the side-chain hydroxy group proceeded without loss of diastereomeric purity. The stereodivergent outcome of the key aza-Michael reactions is the result of thermodynamically versus kinetically controlled cyclization.
- Enkisch, Charlotte,Schneider, Christoph
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experimental part
p. 5549 - 5564
(2010/02/28)
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- Synthesis of chlamydocin by chelate-Claisen rearrangement
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Chelate-Claisen rearrangement of a chiral allylic ester allows the synthesis of the unusual epoxyketo amino acid Aoe found in chlamydocin, one representative of a group of peptide-based HDAc inhibitors. Wiley-VCH Verlag GmbH & Co. KGaA, 2009.
- Quirin, Christian,Kazmaier, Uli
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body text
p. 371 - 377
(2009/07/04)
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- Dimethyl sulfoxide pivaloyl chloride: A new reagent for oxidation of alcohols to carbonyls
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An efficient procedure for conversion of alcohols to the corresponding carbonyl compounds, an alternative to the classical Swern oxidation, is described. Pivaloyl chloride is employed as a mild and inexpensive electrophile. A possible reaction mechanism is proposed. Copyright Taylor & Francis Group, LLC.
- Dubey, Abhishek,Kandula, Subba Rao V.,Kumar, Pradeep
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p. 746 - 753
(2008/09/16)
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- Process for preparing intermediates to 5-HT4 receptor agonist compounds
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The invention provides 8-azabicyclo[3.2.1 ]octyl intermediates useful for the preparation of 5-HT4 receptor agonist compounds. The invention also provides processes for the preparation of such useful intermediates.
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Page/Page column 4
(2008/06/13)
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- Rapid and efficient access to meso-2,5-cis-disubstituted pyrrolidines by double aza-Michael reactions of chiral primary amines
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The double aza-Michael reaction of enantiopure primary amines on bis α,β-unsaturated diesters has been studied under various activating conditions. High pressure allowed a rapid and efficient access to meso-2,5-disubstituted pyrrolidines.
- Cabral dos Santos, Leila,Bahlaouan, Zineb,El Kassimi, Khadija,Troufflard, Claire,Hendra, Frederic,Delarue-Cochin, Sandrine,Zahouily, Mohamed,Cave, Christian,Joseph, Delphine
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experimental part
p. 751 - 768
(2009/09/25)
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- Generation of mono- and bis-dioxiranes from 2,3-butanedione
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Biacetyl reacts with oxone to give bis-dioxirane [3,3′-dimethyl-3, 3′-bidioxirane, 3B] and mono-dioxirane [1-(3-methyl-dioxiran-3-yl) ethanone, 3A)]. Bis-dioxirane 3B is formed when two oxygens are incorporated into biacetyl, while mono-dioxirane 3A incorporated only one. A greater stability is observed in 3B compared to 3A, which is attributed to an α-dioxiranyl (anomeric) effect in the former. In contrast, 3A suffers from a destabilizing π-electron withdrawing effect from the adjacent carbonyl group.
- Sawwan, Nahed,Greer, Alexander
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p. 5796 - 5799
(2007/10/03)
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- Facile synthesis of α,α′ disubstituted N-hydroxypyrrolidines and N-hydroxypiperidines via double 1,4-addition of hydroxylamine
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A versatile synthesis of α and α′ disubstituted N-hydroxypiperidine and N-hydroxypyrrolidine by consecutive double 1,4-addition of hydroxylamine on the corresponding bis α,β-unsaturated diester is described. This reaction takes place an environmentally friendly (ethanol/water) system and at room temperature.
- Bargiggia, Frédéric C.,Murray, William V.
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p. 3191 - 3193
(2007/10/03)
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