- Multiple on-resin olefin metathesis to form ring-expanded analogues of the lantibiotic peptide, Lacticin 3147 A2
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Chemical synthesis of lantibiotic analogues wherein monosulfide bridges are replaced with other groups can shed light on structure-activity relationships and generate variants that are resistant to aerobic oxidation and have better metabolic stability. This work describes the first complete synthesis of a carbocyclic lantibiotic analogue 2, using sequential on-resin ring-closing olefin metathesis and solution-phase peptide synthesis. The methodology described should find wide application for the preparation of rigidified peptidomimetics containing multiple carbocyclic rings.
- Pattabiraman, Vijaya R.,Stymiest, Jake L.,Derksen, Darren J.,Martin, Nathaniel I.,Vederas, John C.
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Read Online
- COMPOUND HAVING S1P5 RECEPTOR AGONIST ACTIVITY
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Provided is a compound in which the balance of the agonist activity against the S1P5 receptor relative to the S1P1 receptor has been improved in order to develop a pharmaceutical useful for the treatment of SIPs-mediated diseases such as schizophrenia and Binswanger's disease and other neurodegenerative diseases. A compound represented by the general formula (V) (wherein, all the symbols are as defined in the specification) has an improved balance of the agonist activity against the S1P5 receptor relative to the S1P1 receptor, and can thus serve as a therapeutic agent for S1P5-mediated diseases such as schizophrenia and Binswanger's disease and other neurodegenerative diseases.
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Paragraph 0308
(2021/01/14)
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- Total Syntheses of (-)-Englerins A/B, (+)-Orientalols E/F, and (-)-Oxyphyllol
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(-)-Englerin A was synthesized in 20 steps from the commercially available material (R)-(+)-limonene. In addition, (-)-englerin B, (+)-orientalol E/F and (-)-oxyphyllol were obtained from the intermediate in the route. The key steps include a hydroxyl-directing stereoselective and regioselective intramolecular cyclopropanation and a multi-gram-scale stereoselective formal intramolecular [3 + 2] cross cycloaddition ([3 + 2]-IMCC) of a cyclopropane 1,1-diester with a carbonyl. A precursor of 7,10-diastereoisomer of englerins was also obtained.
- Liu, Pengcai,Cui, Yutao,Chen, Kang,Zhou, Xinyue,Pan, Wenyan,Ren, Jun,Wang, Zhongwen
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supporting information
p. 2517 - 2521
(2018/05/17)
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- Catalyst-free synthesis of 3-sulfone nitrile from sulfonyl hydrazides and acrylonitrile in water
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A novel catalyst-free sulfonation reaction for synthesizing 3-sulfone nitrile compounds from sulfonyl hydrazides and acrylonitriles in water, without any metal catalyst, ligand or organic solvent, was demonstrated. This catalyst-free protocol provides a new synthetic method for the construction of 3-sulfone nitrile compounds with excellent yields. The D2O experiment adequately proved that the catalyst-free sulfonation reaction occurs via a Michael addition mechanism and that the hydrogen of 3-sulfone nitrile comes from water.
- Li, Wei,Gao, Lingfeng,Zhuge, Wenyun,Sun, Xu,Zheng, Gengxiu
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supporting information
p. 7819 - 7823
(2017/10/06)
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- Base-mediated tandem sulfonylation and oximation of alkenes in water
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A base-mediated bifunctionalization of alkenes for the synthesis of α-sulfonylethanone oximes was developed in water under metal-free conditions. This reaction features a wide substrate scope and facile starting materials to afford the desired products in high yields.
- Wang, Bin,Tang, Lin,Liu, Liyan,Li, Yanan,Yang, Yu,Wang, Zhiyong
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supporting information
p. 5794 - 5799
(2017/12/26)
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- Spectroscopy and Photochemistry of Triplet 1,3-Dimethylpropynylidene (MeC3Me)
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Photolysis (λ > 472 nm) of 2-diazo-3-pentyne (11) affords triplet 1,3-dimethylpropynylidene (MeC3Me, 33), which was characterized spectroscopically in cryogenic matrices. The infrared, electronic absorption, and electron paramagnetic resonance spectra of MeC3Me (33) are compared with those of the parent system (HC3H) to ascertain the effect of alkyl substituents on delocalized carbon chains of this type. Quantum chemical calculations (CCSD(T)/ANO1) predict an unsymmetrical equilibrium structure for triplet MeC3Me (33), but they also reveal a very shallow potential energy surface. The experimental IR spectrum of triplet MeC3Me (33) is best interpreted in terms of a quasilinear, axially symmetric structure. EPR spectra yield zero-field splitting parameters that are typical for triplet carbenes with axial symmetry (|D/hc| = 0.63 cm-1, |E/hc| = β 0 cm-1), while theoretical analysis suggests that the methyl substituents confer significant spin polarization to the carbon chain. Upon irradiation into the near-UV electronic absorption (λmax 350 nm), MeC3Me (33) undergoes 1,2-hydrogen migration to yield pent-1-en-3-yne (4), a photochemical reaction that is typical of carbenes bearing a methyl substituent. This facile process apparently precludes photoisomerization to other interesting C5H6 isomers, in contrast to the rich photochemistry of the parent C3H2 system.
- Knezz, Stephanie N.,Waltz, Terese A.,Haenni, Benjamin C.,Burrmann, Nicola J.,McMahon, Robert J.
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p. 12596 - 12604
(2016/10/07)
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- Copper-Catalyzed Aerobic Oxidative Reaction of Sulfonyl Hydrazides with Alcohols: An Easy Access to Sulfinates
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A Cu-catalyzed aerobic oxidative reaction between sulfonyl hydrazides and alcohols has been developed. In this reaction, sulfonyl hydrazides act as the sulfinic acid precursors to react with alcohols, resulting in sulfinic esters with up to 72 % yield. This catalytic system tolerates a wide range of sulfonyl hydrazide substrates, and represents a new strategy for the transformation of readily available sulfonyl hydrazides.
- Du, Bingnan,Li, Zan,Qian, Ping,Han, Jianlin,Pan, Yi
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supporting information
p. 478 - 481
(2016/03/08)
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- SAMDI Mass Spectrometry-Enabled High-Throughput Optimization of a Traceless Petasis Reaction
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Development of the self-assembled monolayer/MALDI mass spectrometry (SAMDI) platform to enable a high-throughput optimization of a traceless Petasis reaction is described. More than 1800 unique reactions were conducted simultaneously on an array of self-assembled monolayers of alkanethiolates on gold to arrive at optimized conditions, which were then successfully transferred to the solution phase. The utility of this reaction was validated by the efficient synthesis of a variety of di- and trisubstituted allenes.
- Diagne, Abdallah B.,Li, Shuheng,Perkowski, Gregory A.,Mrksich, Milan,Thomson, Regan J.
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supporting information
p. 658 - 662
(2015/11/17)
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- PREPARING METHOD OF HYDRIZIDE COMPOUNDS
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The present invention relates to a method for preparing hydrazide and, more specifically, to a method for preparing a hydrazide derivative compound by reacting a hydrazine-carbon dioxide coupled compound with an organic acid or sulfonic acid compound.COPYRIGHT KIPO 2015
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Paragraph 0128; 0213; 0224-0226
(2017/01/02)
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- Preparation of fluoroalkenes via the Shapiro reaction: Direct access to fluorinated peptidomimetics
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Fluoroalkenes represent a useful class of peptidomimetics with distinct biophysical properties. Current preparations of this functional group commonly provide mixtures of E- or Z-fluoroalkene diastereomers, and/or mixtures of nonfluorinated products. To directly access fluoroalkenes in good stereoselectivity, a Shapiro fluorination reaction was developed. Fluoroalkene products were accessed in one- or two-step sequences from widely available ketones. This strategy should be useful for the preparation of fluorinated analogs of peptide-based therapeutics, many of which would be challenging to prepare by alternate strategies.
- Yang, Ming-Hsiu,Matikonda, Siddharth S.,Altman, Ryan A.
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supporting information
p. 3894 - 3897
(2013/09/02)
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- Oxidative Mizoroki-Heck-type reaction of arylsulfonyl hydrazides for a highly regio- and stereoselective synthesis of polysubstituted alkenes
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A useful source: Arylsulfonyl hydrazides have been identified as synthetically useful aryl sources for the Pd(OAc)2 catalyzed oxidative Mizoroki-Heck-type reaction under molecular oxygen to provide a convenient access to polysubstituted alkenes in a highly regio- and stereoselective manner (see scheme). The reaction well tolerates various functional groups such as alkoxy, halo, alcohol, carboxylic acid, ester, amide, sulfonamide, and sulfone. Copyright
- Yang, Fu-Lai,Ma, Xian-Tao,Tian, Shi-Kai
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supporting information; experimental part
p. 1582 - 1585
(2012/03/11)
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- Regio- and stereoselective hydrosilylation of immobilized terminal alkynes
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Regio- and stereoselective hydrosilylation of terminal alkynes on solid support using diisopropyl hydrosilanes yielding β-(E)-vinyl silanes with excellent selectivity is reported. The hydrosilylation is catalyzed by Pt(DVDS)/P(iBuNCH2CH2)3N (DVDS = 1,3-divinyl-1,1,3,3-tetramethyl-disiloxane), in which the bulky proazaphosphatrane ligand plays a key role for the selectivity. The immobilized products are characterized with gel phase 13C NMR and 1H high resolution magic angle spinning NMR.
- Pedersen, Palle J.,Henriksen, Jonas,Gotfredsen, Charlotte H.,Clausen, Mads H.
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supporting information; experimental part
p. 6220 - 6223
(2009/04/11)
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- Novel Angiogenesis inhibitors and pharmaceutical/cosmetic applications thereof
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Novel derivatives of fumagalone have the general formula (I): and are useful angiogenes is inhibitors; these can be formulated into pharmaceutical compositions suited for human or veterinary medicine, or can be formulated into cosmetic compositions.
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Page/Page column 12
(2010/11/27)
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- SYNTHESIS OF OPTICALLY ACTIVE 3-DIAZOACETYLRETINALS WITH TRIISOPROPYLPHENYLSULFONYLHYDRAZONE
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An improved synthesis of photoaffinity labeled, optically active retinal derivatives is presented.A stable, easy to handle, glyoxalic acid 2,4,6-triisopropylphenylsulfonylhydrazone (TIPPS) reacts with 3-hydroxyretinal to give the diazoacetylretinal analog in satisfactory yield.
- Ok, Hyun,Caldwell, Charles,Schroeder, Daniel R.,Singh, Anil K.,Nakanishi, Koji
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p. 2275 - 2278
(2007/10/02)
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- Total Synthesis of Cortisol: Application to Selective Deuteriation at C-1 and C-19
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An 11-step total synthesis of cortisol and its application to selective deuteriation at the 19-methyl and the C-1 positions is described.The dihydroxy acetone group at C-17 of prednisone (3) was protected as the bismethylenedioxy derivative (4) and degraded to the ring C/D fragment, oxoindanylpropionic acid (2), by Birch reduction followed by ozonolysis.The reaction of deuterioisopropenyl anion with compound (2) followed by dehydration, cyclisation, and osonolysis produced -4,5-seco-17α,20;20,21-bismethylenedioxypregnane-3,5,11-trione .Cyclisation of (16a) in KOH-MeOH affordedthe bismethylenedioxy cortisone (17), wich upon reduction with KBH4 gave the desired (2)H5 cortisol (19).
- Minagawa, Kazuo,Furuta, Takashi,Kasuya, Yasuji,Fujino, Akiharu,Avery, Mitchell A.,Tanabe, Masato
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p. 587 - 592
(2007/10/02)
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