- C-acylations of polymeric phosphoranylidene acetates for C-terminal variation of peptide carboxylic acids
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(Chemical Equation Presented) C-Acylations of polymer-supported 2-phosphoranylidene acetates ("linker reagents") with protected amino acids yielded 2-acyl-2-phosphoranylidene acetates as flexible intermediates for the C-terminal variation of carboxylic acids: peptidyl-2,3-diketoesters, peptidyl vinyl ketones, peptidyl-2-ketoaldehydes, and 1,3-diamino-2-hydroxy- propanes were obtained as products.
- El-Dahshan, Adeeb,Weik, Steffen,Rademann, Joerg
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Read Online
- Combination detergent/MALDI matrix: Functional cleavable detergents for mass spectrometry
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This study reports the synthesis of the first functional cleavable detergent designed specifically for applications in mass spectrometry. Upon cleavage, two inert compounds and the MALDI matrix are formed, eliminating sources of potential interference ori
- Norris, Jeremy L.,Porter, Ned A.,Caprioli, Richard M.
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Read Online
- Cross coupling of sulfonyl radicals with silver-based carbenes: A simple approach to β-carbonyl arylsulfones
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A coupling reaction between sulfonyl radicals and silver-based carbenes has been well established. This simple radical-carbene coupling (RCC) process provided an efficient approach to a variety of β-carbonyl arylsulfones from sodium arylsulfinates and diazo compounds, and was characterized by wide substrate scope, easy scale-up, simple manipulation, accessible starting materials, and mild reaction conditions.
- Li, Jingjing,Lian, Pengcheng,Wan, Xiaobing,Wang, Hanghang,Zheng, Yonggao
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supporting information
p. 2163 - 2169
(2020/03/27)
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- Oxazolidinone compound as well as preparation method, application and pharmaceutical composition thereof
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The invention relates to an oxazolidinone compound used as an Lp-PLA2 covalent inhibitor and a pharmaceutical composition of the oxazolidinone compound, the structure of the oxazolidinone compound isshown as a general formula I, and R1, R2 and R3 are defined as the specification and claims. The compound shown in the general formula I or the stereoisomer or the pharmaceutically acceptable salt thereof can be used as the Lp-PLA2 covalent inhibitor to prevent and/or treat and/or improve diseases related to Lp-PLA2 enzyme activity. Meanwhile, the stereoisomer or the pharmaceutically acceptable salt of the compound shown in the general formula I can be used as an Lp-PLA2 specific molecular probe.
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Paragraph 0097-0099
(2020/11/05)
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- In Situ Generation of Oxazole Ylide and Interception with Sulfonamide: Construction of Amidines Using Two Diazo Molecules
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A novel generation of oxazole ylide and interception with sulfonamide have been well developed to construct fully substituted amidines. This copper-catalyzed four-component reaction incorporates two diazo molecules to target amidines and shows broad substrate scope, excellent functional groups tolerance and good to excellent yields.
- Chen, Jijun,Long, Wenhao,Zhao, Yanwei,Li, Haiyan,Zheng, Yonggao,Lian, Pengcheng,Wan, Xiaobing
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supporting information
p. 857 - 865
(2018/07/31)
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- In Situ Generation of Quinolinium Ylides from Diazo Compounds: Copper-Catalyzed Synthesis of Indolizine
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The Cu-catalyzed three-component reaction between quinolines, diazo compounds, and alkenes has been established for direct construction of indolizine derivatives via quinolinium ylides. This methodology is distinguished by the use of a commercially inexpensive catalyst and readily available starting materials, wide substrate scope, and operational simplicity.
- Chen, Rongxiang,Zhao, Yanwei,Sun, Hongmei,Shao, Ying,Xu, Yudong,Ma, Meihua,Ma, Liang,Wan, Xiaobing
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p. 9291 - 9304
(2017/09/22)
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- HDAC Inhibitors as Anti-Cancer Agents
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Largazole analogues, methods of making the same, and methods of using the same, are described.
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Paragraph 0204
(2016/01/15)
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- Radical decarboxylative fluorination of aryloxyacetic acids using N-fluorobenzenesulfonimide and a photosensitizer
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Fluorinated methoxy arenes are emerging as important motifs in both agrochemicals and pharmaceuticals. A novel technique for the synthesis of monofluoromethoxy arenes through the direct fluorodecarboxylation of carboxylic acids was developed that uses photosensitizers and N-fluorobenzenesulfonimide (NFSI). Utilization of the oxidatively mild fluorine transfer agent NFSI enabled the synthesis of fluoromethyl ethers that were previously inaccessible with decarboxylative fluorinations performed with Selectfluor. Mechanistic studies are consistent with the photosensitizer effecting oxidation of the aryloxyacetic acid.
- Leung, Joe C. T.,Sammis, Glenn M.
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supporting information
p. 2197 - 2204
(2015/04/14)
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- Flexible, polymer-supported synthesis of sphingosine derivatives provides ceramides with enhanced biological activity
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A polymer-supported route for the synthesis of sphingosine derivatives is presented based on the C-acylation of polymeric phosphoranylidene acetates with an Fmoc-protected amino acid. The approach enables the flexible variation of the sphingosine tail through a deprotection-decarboxylation sequence followed by E-selective Wittig olefination cleavage. d-Erythro-sphingosine analogs have been synthesized by diastereoselective reduction of the keto group employing LiAlH(O-tBu)3as reducing agent. The effect of ceramides and keto-ceramides on the proliferation of three cancer cell lines HEP G-2, PC-12 and HL-60 was investigated and a ceramide containing an aromatic sphingosine tail was identified as being most active.
- El-Dahshan, Adeeb,Al-Gharabli, Samer I.,Radetzki, Silke,Al-Tel, Taleb H.,Kumar, Pradeep,Rademann, J?rg
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p. 5506 - 5512
(2014/12/11)
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- Asymmetric synthesis of (+)-vertine and (+)-lythrine
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The total syntheses of the Lythracea alkaloids (+)-vertine and (+)-lythrine are described. Enantioenriched pelletierine is used as a chiral building block and engaged into a two step pelletierine condensation leading to two quinolizidin-2-one diastereomers in a 8:1 ratio. The major product is used in the synthesis of (+)-vertine via aryl-aryl coupling and ring closing metathesis to provide a Z-alkene α to the lactone carbonyl function. The same procedure was used for (+)-lythrine after base induced epimerization of the main quinolizidin-2-one diastereomer. Alternative classical ring closure strategies like macrolactonisation or aryl-aryl coupling failed.
- Chausset-Boissarie, La?titia,àrvai, Roman,Cumming, Graham R.,Guénée, Laure,Kündig, E. Peter
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supporting information; experimental part
p. 6473 - 6479
(2012/09/08)
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- NOVEL MACROCYLES AND METHODS FOR THEIR PRODUCTION
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There are provided compounds of formula (I) or a pharmaceutically acceptable salt thereof: wherein the variables R1-R3 are as described in the description, said compounds being useful as anti-inflammatory agents with reduced systemic effects.
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Page/Page column 50-51
(2011/05/05)
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- A concise asymmetric total synthesis of aspidophytine
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An expedient asymmetric total synthesis of aspidophytine is reported. A highly convergent strategy involving the sequential annulation of vinyl iodide 5 with indole 6 exploits varying modes of indole reactivity to provide aspidophytine in 23% over six steps from 5. Copyright
- Nicolaou,Dalby, Stephen M.,Majumder, Utpal
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supporting information; experimental part
p. 14942 - 14943
(2009/03/12)
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- Structure reassignment and synthesis of jenamidines A1/A 2, synthesis of (+)-NP25302, and formal synthesis of SB-311009 analogues
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The proposed structures of jenamidines A, B, and C (1-3) were revised to jenamidines A1/A2, B1/B2, and C (8-10). Jenamidines A1/A2 (8) were synthesized from activated proline derivative 43 by conversion to 26 in two steps and 50% overall yield. Acylation of 26 with acid chloride 38d gave 39d, which was deprotected with TFA and then mild base to give 8 in 45% yield from 26. (-)-trans-2,5- Dimethylproline ethyl ester (49) was prepared by the enantioselective Michael reaction of ethyl 2-nitropropionate (51) and methyl vinyl ketone (50) using modified dihydroquinine 60 as the catalyst. Further elaboration converted 49 to natural (+)-NP25302 (12). A Wittig reaction of proline NCA (76) with ylide 79 gave 72 as a 9/1 E/Z mixture in 27% yield, completing a one-step formal synthesis of SB-311009 analogues.
- Duvall, Jeremy R.,Wu, Fanghui,Snider, Barry B.
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p. 8579 - 8590
(2007/10/03)
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- Phosphine-catalyzed synthesis of 1,3-dioxan-4-ylidenes
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(Chemical Equation Presented) A phosphine-catalyzed reaction of an allenoate with aldehydes furnished (2,6-diaryl-[1,3]dioxan-4-ylidene)-acetates 4 in excellent to moderate yields with complete diastereoselectivity and high E/Z-selectivities. Upon removal of the acetal functionality in this domino reaction product 4, δ-hydroxy-β-ketoester 11 was obtained. The reported vinylphosphonium-based approach provides a new way to achieve a synthesis of δ-hydroxy-β-ketoesters that differs from the classical dianion-based approach.
- Zhu, Xue-Feng,Henry, Christopher E.,Wang, Jay,Dudding, Travis,Kwon, Ohyun
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p. 1387 - 1390
(2007/10/03)
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- Phosphine-catalyzed synthesis of 6-substituted 2-pyrones: Manifestation of E/Z-isomerism in the zwitterionic intermediate
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(Chemical Equation Presented) We report a one-step phosphine-catalyzed annulation between aldehydes and ethyl allenoate to form 6-substituted 2-pyrones. The mechanistic rationale for this reaction requires explicit discussion of the E/Z-isomerism of the zwitterionic intermediate formed by the addition of a phosphine to the allenoate. Sterically demanding trialkylphosphines facilitate the shift of equilibrium toward the E-isomeric zwitterion and lead to the formation of 6-substituted 2-pyrones. Various aromatic as well as aliphatic aldehydes undergo the transformation in moderate to excellent yield.
- Zhu, Xue-Feng,Schaffner, Arnaud-Pierre,Li, Ronald C.,Kwon, Ohyun
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p. 2977 - 2980
(2007/10/03)
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- Cleavable surfactants and methods of use thereof
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Cleavable compositions and methods of use especially in MALDI MS analysis of hydrophobic proteins.
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- 6-methoxy-2-naphthylacetic acid prodrugs
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The present invention provides compositions useful for the treatment of inflammation in humans, and related methods of treatment for the same. In one embodiment the composition is In another embodiment, the composition is In yet another embodiment, the composition is Additional alternative embodiments are R or R″ are therapeutic moieties.
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- Total synthesis of the microtubule stabilizing antitumor agent laulimalide and some nonnatural analogues: The power of sharpless' asymmetric epoxidation
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Three different routes are described for the synthesis of deoxylaulimalide (3), which is the immediate precursor of the marine sponge metabolite laulimalide (1). These routes mainly differ with respect to their ring closing step. Thus, route 1 uses a Still-Gennari olefination, route 2 a Yamaguchi lactonization, and route 3 an intramolecular allylsilane-aldehyde addition for establishing the macrocyclic structure. The unprotected deoxy derivative 3 was subjected to Sharpless' asymmetric epoxidation (SAE). With (R,R)-tartrate the 16,17-epoxide laulimalide (1) is formed selectively, whereas (S,S)-tartrate generates the 21,22-epoxide 142. This demonstrates the high reagent control involved in the SAE process, which in this case is used to achieve high stereo- and regioselectivity. Laulimalide and some derivatives thereof have been tested with respect to antitumor activity and compared to standard compounds paclitaxel and epothilone B.
- Ahmed, Anjum,Hoegenauer, E. Kate,Enev, Valentin S.,Hanbauer, Martin,Kaehlig, Hanspeter,Ohler, Elisabeth,Mulzer, Johann
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p. 3026 - 3042
(2007/10/03)
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- 6-methoxy-2-naphthylacetic acid prodrugs
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The present invention provides compositions useful for the treatment of inflammation in humans, and related methods of treatment for the same. In one embodiment the composition is In another embodiment, the composition is In yet another embodiment, the composition is Additional alternative embodiments are R or R″ are therapeutic moieties.
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- Transformation of vitamin B6 to (+)-deoxypyridinoline, a useful biochemical marker for diagnosis of bone diseases
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A versatile chiral synthesis of the cross-link (+)-deoxypyridinoline (Dpd, 2) was achieved starting from vitamin B6 (7). The key steps in the synthesis of (+)-2 are transformation of B6 (7) to the chloride (3d) and construction of three α-amino acid chains by utilizing (R)-(-)-Schollkopf's reagent (4), Wittig reagent (R)-(-)-5, and iodide (5)-(-)-6. (+)-Dpd (2) is a degradation product of bone collagen and has been found to be a useful marker for diagnosis of osteoporosis and other metabolic bone diseases. (C) 2000 Elsevier Science Ltd.
- Adamczyk, MacIej,Akireddy, Srinivasa Rao,Reddy, Rajarathnam E.
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p. 2379 - 2390
(2007/10/03)
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- STUDIES RELATED TO THE SYNTHESIS OF (+/-)-PEDERIN. PART 1. SYNTHESIS OF ETHYL PEDERATE AND BENZOYLSELENOPEDERIC ACID.
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The first in a series of 2 papers on the synthesis of the insect toxin pederin (1) begins with a discussion of synthesis of the ring A fragments (+/-) pederate (2) and (+/-)-benzoylselenopederic acid (4).A silicon-mediated intramolecular cyclisation of a
- Willson, Timothy M.,Kocienski, Philip,Jarowicki, Krzysztof,Isaac, Kim,Faller Andrew,et al.
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p. 1757 - 1766
(2007/10/02)
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- The Total Synthesis of (+/-)-Pederin
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The conjugate addition of phenylselenomethyl-lithium to the α,β-unsaturated lactone (4) was a key step in a short synthesis of (+/-)-benzoylselenopederic acid (2); union of (2) and (+/-)-benzoylpedamide (3) by a modification of known procedures gave (+/-)-pederin (1).
- Willson, Timothy,Kocienski, Philip,Faller, Andrew,Campbell, Simon
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p. 106 - 108
(2007/10/02)
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- Enantiomerically Pure Synthetic Building Blocks with Four C-Atoms and Two or Three Functional Groups from β-Hydroxy-butanoic, Malic, and Tartaric Acid
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The pool of chiral, non-racemic electrophilic building blocks, which are available from simple natural products in both enantiomeric forms is enlarged by the epoxides 3, 5, and 10, by the tosylate 12a, and by the aldehydes 18 (cf. symbols A-D, 14, and Scheme 1).Key steps of the conversions leading from hydroxyacids to the building blocks are: epoxide-opening by triethylborohydride (1 --> 2a) and tosylate reduction (12a --> 12b); the Mitsunobu inversion (2a --> 4a); the reduction of (R,R)-tartaric ester to (R)-malic ester by NBS (N-bromosuccinimide) opening of the benzaldehyde acetal 8 and tin hydride reduction (6c -->7c); the enantiomer enrichment of optically active ethyl β-hydroxy-butanoate through the crystalline dinitrobenzoate 21b.Detailed procedures are given for large scale preparations of the key intermediates.The enantiomeric purities of the building blocks are secured by correlations.
- Hungerbuehler, Ernst von,Seebach, Dieter,Wasmuth, Daniel
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p. 1467 - 1487
(2007/10/02)
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