- Second-generation dimeric inhibitors of chitin synthase
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Chitin synthase (CS) is essential for fungal cell wall biosynthesis and is an attractive medicinal target. Expanded results from our efforts to develop mechanism based inhibitors of CS are presented here. Specifically, we describe uridine dimers linked by tartrate amides as potential pyrophosphate mimics.
- Yeager, Adam R.,Finney, Nathaniel S.
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Read Online
- Design, synthesis and evaluation of 2,2-dimethyl-1,3-dioxolane derivatives as human rhinovirus 3C protease inhibitors
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The human rhinovirus (HRV) is the most significant cause of the common cold all over the world. The maturation and replication of this virus entirely depend on the activity of a virus-encoded 3C protease. Due to the high conservation among different serot
- Zhang, Qiyan,Cao, Ruiyuan,Liu, An,Lei, Shihai,Li, Yuexiang,Yang, Jingjing,Li, Song,Xiao, Junhai
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Read Online
- Domino Hydroalkoxylation-[4+2]-Cycloaddition for Stereoselective Synthesis of 1,4-Heterocycle-Fused Chromenes: Rapid Access to the [6-6-7-6] Tetracyclic Core of Cytorhizhins B–D
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A substrate dependent regio- and stereoselective domino hydroalkoxylation-formal-[4+2] cycloaddition is described for the facile synthesis of linear as well as spirocyclic 1,4-heterocycle-fused chromene ketals. Enantiospecific synthesis of oxazepino chromene derivatives was successfully carried out using chiral pool amino alkynols. The developed hydroalkoxylation cascade offered rapid access to the spirocyclic [6-6-7-6] tetracyclic core of cytorhizhins B–D with correct relative configuration.
- Fartade, Dipak J.,Gharpure, Santosh J.,Nanda, Santosh K.,Vishwakarma, Dharmendra S.
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supporting information
p. 6892 - 6897
(2020/01/25)
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- A Synthesis Strategy for the Production of a Macrolactone of Gulmirecin A via a Ni(0)-Mediated Reductive Cyclization Reaction
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A synthesis strategy for the production of a key synthetic intermediate of gulmirecin A was described. The key reaction in the preparation of the 12-membered macrolactone is the Ni(0)-mediated reductive cyclization reaction of ynal using an N-heterocyclic carbene ligand and silane reductant. In addition, the α-selective glycosylation reaction of the macrolactone was performed to demonstrate the synthesis of gulmirecin and disciformycin precursors.
- Ichikawa, Satoshi,Katsuyama, Akira,Kitahata, Shun
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supporting information
(2020/03/30)
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- Enantioselective vinylation of aldehydes with the vinyl Grignard reagent catalyzed by magnesium complex of chiral BINOLs
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Enantioselective vinylation of aldehydes via direct catalytic asymmetric Grignard reaction of aldehdyes and the vinyl Grinard reagent is a long-standing challenge. This work demonstrated that the magnesium (S)-3,3′-dimethyl BINOLate enantioselectively catalyze the direct vinylation of aldehydes with the deactivated vinylmagnesium bromide by bis(2-[N,N′-dimethylamino]ethyl) ether (BDMAEE) in the addition of n-butylmagnesium chloride. The highest ee of 63% was achieved up to date.
- Wang, Pei,Ma, Guo-Rong,Yu, Sheng-Li,Da, Chao-Shan
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supporting information
p. 79 - 86
(2018/12/13)
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- 2,2-dimethyl-1,2-dioxolame derivative, preparation method and application thereof
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The invention relates to a compound shown in formula I, a despinner or optical isomer thereof, pharmacologically acceptable salt, solvate and hydrate thereof, pharmaceutical composition containing thecompound, and application of the compound in preparatio
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Paragraph 0119-0120
(2019/01/23)
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- HETEROCYCLIC COMPOUNDS AS PRMT5 INHIBITORS
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The compounds of Formula I, Formula Ia, and Formula Ib are described herein along with their analogs, tautomeric forms, stereoisomers, polymorphs, hydrates, solvates, pharmaceutically acceptable salts, pharmaceutical compositions, metabolites, and prodrugs thereof. These compounds inhibit PRMT5 and are useful as therpeautic or ameliorating agent for diseases that are involved in cellular growth such as malignant tumors, schizophrenia, Alzheimer's disease, Parkinson's disease and the like.
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Paragraph 000333
(2019/06/11)
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- Supramolecular gels from sugar-linked triazole amphiphiles for drug entrapment and release for topical application
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A simple molecular framework obtained by cross-linking a hydrophobic chain with S,S- and R,R-tetritol by the copper-catalysed azide-alkyne cycloaddition reaction is found to serve as an excellent bioisostere for self-assembly. The hexadecyl-linked triazolyl tetritol composite spontaneously self-assembles in n-hepane and methanol to form hierarchical organogels. Microscopic analyses and X-ray diffraction studies demonstrate eventual formation of nanotubes through lamellar assembly of the amphiphiles. A rheological investigation shows solvent-dictated mechanical properties that obey power law behavior similar to other low molecular weight gelators (LMOGs). The gel network was then utilized for the entrapment of drugs e.g. ibuprofen and 5-fluorouracil, with tunable mechanical behaviour under applied stress. The differential release profiles of the drugs over a period of a few hours as a result of the relative spatio-temporal location in the supramolecular network can be utilized for topical formulations.
- Sharma, Komal,Joseph, Jojo P.,Sahu, Adarsh,Yadav, Narender,Tyagi, Mohit,Singh, Ashmeet,Pal, Asish,Kartha, K.P. Ravindranathan
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p. 19819 - 19827
(2019/07/05)
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- Preparation method of chiral catalyst ligand TADDOLs in asymmetric synthesis
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The invention discloses a preparation method of a chiral catalyst ligand TADDOLs in asymmetric synthesis. The preparation method comprises the following steps of using chiral diethyl tartrate as raw material, and reacting with 2,2-dimethoxypropane and triethyl orthoformate, so as to obtain O,O-isopropylidene diethyl tartrate; enabling brominated aromatic hydrocarbon and isopropyl magnesium bromideto react in a solvent; finally, adding the O,O-isopropylidene diethyl tartrate, so as to obtain a target product, namely the chiral catalyst ligand TADDOLs. The preparation method has the advantagesthat the raw materials are bulk chemicals, the industrial cost is low, the reaction process is moderate and controllable, the post-treatment is concise and efficient, the difficulty in industrial production of the series of compound is decreased, and the cost is reduced; the chiral catalyst ligand TADDOLs has been widely applied into the asymmetric chiral synthesis; especially, when the chiral catalyst ligand TADDOLs and metal form a complex as the catalyst in the chiral oriented synthesis, the effect is obvious; the catalyzing effect is excellent, the process of chiral detachment of despinner compound is reduced, and the synthesis cost of chiral medicine is reduced.
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Paragraph 0042; 0043; 0051
(2018/04/03)
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- Enantioselective Ni-Al Bimetallic Catalyzed exo -Selective C-H Cyclization of Imidazoles with Alkenes
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A Ni-Al bimetallic catalyzed enantioselective C-H exo-selective cyclization of imidazoles with alkenes has been developed. A series of bi- or polycyclic imidazoles with β-stereocenter were obtained in up to 98% yield and >99% ee. The bifunctional SPO ligand-promoted bimetallic catalysis proved to be critical to this challenging stereocontrol.
- Wang, Yin-Xia,Qi, Shao-Long,Luan, Yu-Xin,Han, Xing-Wang,Wang, Shan,Chen, Hao,Ye, Mengchun
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supporting information
p. 5360 - 5364
(2018/05/01)
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- Stereoselective synthesis of the lichen metabolite, (+) montagnetol and its congeners as antimicrobial agents
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In view of structural diversity, (+) montagnetol, the major metabolite of the fruticose lichen, Roccella montagnei was synthesized along with three of its congeners by employing highly efficient protocols. (+) Montagnetol (2 R, 3S; 11) and (-) montagnetol (2S, 3R; 5) were synthesized in 7 and 9 steps, respectively, from L-ascorbic acid. The two new congeners 3 (2 R, 3R) and 6 (2S, 3S), which differ in configuration at C-2 and C-3 positions of the (+) montagnetol, were synthesized from (?) diethyl D-tartrate and (+) diethyl L-tartrate, respectively. The synthesized compounds were evaluated in vitro for antimicrobial activity against two Gram-positive (S. aureus and E. coli) and two Gram-negative (S. typhi and P. aeruginosa) bacteria and one fungal strain Candida albicans. Interestingly, the congener 3 showed promising anti-bacterial activity (MIC: 0.062 μg/ml) against P. aeruginosa, whereas the congener 6 displayed potent anti-fungal activity (MIC: 0.062 μg/ml) against C. Albicans.
- Mallavadhani, Uppuluri Venkata,Boddu, Ramakrishna,Rathod, Balaji B.,Reddy Setty, Prakasam
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p. 2992 - 2999
(2018/10/15)
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- Synthesis of β-Lactams by Palladium(0)-Catalyzed C(sp3)?H Carbamoylation
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A general and user-friendly synthesis of β-lactams is reported that makes use of Pd0-catalyzed carbamoylation of C(sp3)?H bonds, and operates under stoichiometric carbon monoxide in a two-chamber reactor. This reaction is compatible with a range of primary, secondary and activated tertiary C?H bonds, in contrast to previous methods based on C(sp3)?H activation. In addition, the feasibility of an enantioselective version using a chiral phosphonite ligand is demonstrated. Finally, this method can be employed to synthesize valuable enantiopure free β-lactams and β-amino acids.
- Dailler, David,Rocaboy, Ronan,Baudoin, Olivier
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supporting information
p. 7218 - 7222
(2017/06/13)
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- Synthesis and biological evaluation of novel 3-substituted amino-4-hydroxylcoumarin derivatives as chitin synthase inhibitors and antifungal agents
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A series of novel 3-substituted amino-4-hydroxycoumarin derivatives have been designed and synthesized as chitin synthase (CHS) inhibitors. All the synthesized compounds have been screened for their CHS inhibition activity and antimicrobial activity in vitro. The enzymatic assay indicated that most of the compounds have good inhibitory activity against CHS, in which compound 6o with IC50 of 0.10 mmol/L had stronger activity than that of polyoxins B, which acts as control drug with IC50 of 0.18 mmol/L. As far as the antifungal activity is concerned, most of the compounds possessed moderate to excellent activity against some representative pathogenic fungi. Especially, compound 6b was found to be the most potent agent against Cryptococcus neoformans with minimal inhibitory concentration (MIC) of 4 g/mL. Moreover, the results of antibacterial screening showed that these compounds have negligible actions to some tested bacteria. Therefore, these compounds would be promising to develop selective antifungal agents.
- Ge, Zhiqiang,Ji, Qinggang,Chen, Chunyan,Liao, Qin,Wu, Hualong,Liu, Xiaofei,Huang, Yanrong,Yuan, Lvjiang,Liao, Fei
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p. 219 - 228
(2016/02/03)
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- A facile approach for the synthesis of C13-C24 fragments of maltepolides A, C and D
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A linear, chiron approach for the synthesis of C13-C24 fragments of cytostatic maltepolides A, C and D consisting of a tetrahydrofuran subunit and a chiral alkenyl/alkyl substituent is achieved from (+)-diethyl l-tartrate. The other chiral stereocenters were generated by employing key reactions such as Crimmins aldol, alkynylation and CeCl3·7H2O mediated Luche reduction reactions.
- Rao, P. Sankara,Srihari
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p. 9629 - 9638
(2016/10/22)
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- Total synthesis of ivorenolide a following a base-induced elimination protocol
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A concise and stereocontrolled first total synthesis of Ivorenolide A (1) is reported in 16 longest linear steps with a 13.4% overall yield starting from (+)-diethyl tartrate (DET). Key features are base-induced elimination protocol for the construction of chiral propargyl alcohols in both fragments, Pd-catalyzed cross-coupling of terminal acetylenes, and Shiina's 2-methyl-6-nitrobezoic anhydride (MNBA) mediated macrolactonization.
- Mohapatra, Debendra K.,Umamaheshwar, Gonela,Rao, R. Nageshwar,Rao, T. Srinivasa,R, Sudheer Kumar,Yadav, Jhillu S.
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supporting information
p. 979 - 981
(2015/03/30)
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- Synthesis of diacylglycerol analogs bearing photoaffinity tags for labelling mammalian diacylglycerol kinase
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Signaling lipids such as diacylglycerol (DAG), phosphatidic acid, and the phosphatidylinositol polyphosphates are site-specific ligands for protein binding partners. Herein, we report the apotheoses of our initial approach to the development of diverse probes which are vital for understanding lipid-protein interactions. When incorporated into liposomes, these probes reduce mammalian diacylglycerol kinase's (DGK) enzymatic activity in a concentration, time, and light dependent manner. This journal is
- Eni, Sammy Eni,Rowland, Meng,Best, Michael D.
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p. 25457 - 25461
(2015/03/30)
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- Synthesis and electrochemical properties of a chiral silyl-substituted tetrathiafulvalene derivative
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A new chiral tetrathiafulvalene (TTF) derivative and related silyl-substituted 1,3-dithiole-2-(thi)one compounds were synthesized and characterized by 1H NMR, 13C NMR, MS and IR spectra. Single crystal structure of the silyl-substituted 1,3-dithiole-2-one revealed the high degree of conjugation of the five-membered ring moiety in the compound. The electrochemical properties of the new TTF derivative were studied by cyclic voltammetry and the results indicated that the electron-donating ability of the chiral TTF derivative was similar to that of BEDT-TTF. The ΔE value for the new TTF derivative was smaller than those for TTF and BEDT-TTF, indicative of decreased Coulombic repulsion in the dicationic redox state. Formation of charge-transfer (CT) complex between the new donor and electron acceptor 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) was demonstrated.
- Liang, Guo-Qi,Zhang, Zhong-Bao,Li, Hong-Qi,Wang, Ya-Ping,Xian, Chun-Ying
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p. 579 - 582
(2014/05/06)
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- A facile chiral pool synthesis of 9-epi-decarestrictine-D, decarestrictine-D and O
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A facile chiral pool total synthesis of 9-epi-decarestrictine-D, decarestrictine-D and O has been achieved from l-(+)-diethyl tartrate. The strategy utilized is conventional and flexible. Wittig homologation and Grubbs ring closing metathesis are the key reactions employed for the synthesis of the title molecules.
- Vamshikrishna, Kuchena,Srinu, Garlapati,Srihari, Pabbaraja
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p. 203 - 211
(2014/03/21)
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- Synthesis and protein kinase C (PKC)-C1 domain binding properties of diacyltetrol based anionic lipids
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The protein kinase C (PKC) family of lipid-activated kinases plays a significant role in the regulation of diverse cellular functions including tumor promotion, apoptosis, differentiation, and others. The lipophilic second messenger diacylglycerols (DAGs) act as endogenous ligands for the PKCs in the presence of anionic phospholipids. To develop effective PKC regulators and understand the importance of anionic phospholipids in DAG binding of PKC isoforms, we conveniently synthesized octanoic acid containing diacyltetrol (DAT) based hybrid lipids with both DAG and anionic phospholipid headgroups within the same molecule. We also used palmitic and oleic acid containing hybrid lipids for additional understanding of the PKC-C1 domain binding mechanism. Biophysical studies showed that hydrophobic side chains, DAG and anionic phospholipids headgroups are necessary for their interaction with the C1-domain of PKC isoforms. The hybrid lipids DAT-PS and DAT-PA specifically interact with the PKCδ-C1b and PKCθ-C1b subdomains and showed 5- and 2.5-fold stronger binding affinity compared with DAG, respectively. Whereas, the PKCα-C1a subdomain interacts with the hybrid lipids, without any significant specificity. The present results show that hybrid lipids bind to the PKC C1b/a subdomains and can be further studied to decipher their binding mechanism and biological activities. This study proposes a new concept of developing PKC activators by using tetrol-based anionic hybrid lipids having both phospholipids and diacylglycerol headgroups within the same molecule. This study also supplies useful information for the binding potencies of hybrid lipids with PKC-C1 domains. This journal is
- Mamidi, Narsimha,Panda, Subhankar,Borah, Rituparna,Manna, Debasis
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p. 3002 - 3013
(2015/01/08)
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- A convergent approach for the total synthesis of the α-glucosidase inhibitor (-)-panaxjapyne-C
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The stereoselective total synthesis of (-)-panaxjapyne-C was accomplished in a convergent fashion. The synthesis utilizes the readily available enantiomers l-(+)-diethyltartrate and d-(-)-diethyltartrate and involves a Cadiot-Chodkiewicz coupling reaction, and an Ohira-Bestmann reaction as the key steps.
- Sathish Reddy,Gangadhar,Srihari
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p. 1524 - 1530
(2013/12/04)
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- Stereoselective total synthesis of paecilomycin e
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First total synthesis of recently isolated resorcylic acid lactone paecilomycin E has been accomplished. The key reactions include olefin metathesis, Mitsunobu reaction, Stille coupling and regioselective allylation.
- Srihari,Mahankali,Rajendraprasad
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supporting information; experimental part
p. 56 - 58
(2012/01/06)
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- An efficient chiral-pool synthesis of botryolide-E
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An efficient stereoselective total synthesis of botryolide-E by a chiral-pool approach is described. 2012 Elsevier Ltd. All rights reserved.
- Madabhushi, Sridhar,Godala, Kondal Reddy,Beeram, China Ramanaiah,Chinthala, Narsaiah
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supporting information
p. 5539 - 5540
(2012/11/07)
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- AMPHIPHILIC COMPOUNDS AND SELF-ASSEMBLING COMPOSITIONS MADE THEREFROM
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The present disclosure relates to amphiphilic compounds, self assembling compositions formed from the amphiphilic compounds and methods of making such compositions.
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Page/Page column 9
(2012/03/12)
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- An efficient stereoselective approach for the synthesis of (+)-(4S,5S)-muricatacin
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An efficient stereoselective total synthesis of (+)-(4S,5S)-muricatacin was accomplished in good yields from inexpensive, commercially available chemicals ((+)-diethyl tartrate (DET) and undecan-1-ol) by utilizing Mitsunobu and Julia-Kocienski reactions, Wittig homologation, Swern oxidation, and lactonization. Copyright
- Srinivas, Chiguru,Naga Sesha Sai Pavan Kumar, Chebolu,China Raju, Bhimapaka,Jayathirtha Rao, Vaidya
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experimental part
p. 669 - 674
(2011/06/18)
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- An efficient formal synthesis of (S)-dapoxetine from enantiopure 3-hydroxy azetidin-2-one
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An efficient formal synthesis of S-(+) dapoxetine starting from 3-hydroxy azetidin-2-one is described. The intermediate (S)-3-(dimethyl amino)-3-phenylpropan-1-ol was synthesized in enantiopure form starting with 3-hydroxy azetidin-2-one in seven steps.
- Chincholkar, Pinak M.,Kale, Ajaykumar S.,Gumaste, Vikas K.,Deshmukh, Abdul Rakeeb A.S.
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scheme or table
p. 2605 - 2609
(2009/08/08)
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- Fast and efficient synthesis of the complete LL-Z1640-2 framework
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The convergent synthesis of the complete LL-Z1640-2 framework has been completed. This fast and efficient approach provides flexible access into the resorcyclic lactones.
- Henry, Neil,Robertson, Murray N.,Marquez, Rodolfo
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p. 6088 - 6091
(2008/03/12)
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- An efficient synthesis of (-)-posticlure: The sex pheromone of Orgyia postica
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An efficient multigram synthesis of (-)-posticlure, the first frans-epoxide sex pheromone found in Orgyia postica, from diethyl L-tartrate is described. The synthesis was completed in seven steps and 27 % overall yield. The synthetic strategy features double-Wittig olefination and a stereoselective one-pot conversion of diol to epoxide as the key steps. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
- Fernandes, Rodney A.
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p. 5064 - 5070
(2008/03/18)
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- An efficient synthesis of azetidine-2,3-diones from L-(+)-diethyl tartrate
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A convenient route to enantiopure azetidine-2,3-diones is described. The chiral ketene generated from commercially available L-(+)-diethyl tartrate on Staudinger cycloaddition with different imines gave spiro-β-lactams in good yields. These spiro-β-lactam
- Chincholkar, Pinak M.,Puranik, Vedavati G.,Deshmukh, Abdul Rakeeb A. S.
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p. 2242 - 2246
(2008/02/10)
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- Structure-based design, synthesis and preliminary evaluation of selective inhibitors of dihydrofolate reductase from Mycobacterium tuberculosis
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Tuberculosis is an increasing threat, owing to the spread of AIDS and to the development of resistance of the causative organism, Mycobacterium tuberculosis, to the currently available drugs. Dihydrofolate reductase (DHFR) is an important enzyme of the folate cycle; inhibition of DHFR inhibits growth and causes cell death. The crystal structure of M. tuberculosis DHFR revealed a glycerol tightly bound close to the binding site for the substrate dihydrofolate; this glycerol-binding motif is absent from the human enzyme. A series of pyrimidine-2,4-diamines was designed with a two-carbon tether between a glycerol-mimicking triol and the 6-position of the heterocycle; these compounds also carried aryl substituents at the 5-position. These, their diastereoisomers, analogues lacking two hydroxy groups and analogues lacking the two-carbon spacing linker were synthesised by acylation of the anions derived from phenylacetonitriles with ethyl (4S,5R)-4-benzyloxymethyl-2,2-dimethyl-1,3-dioxolane-4-propanoate, ethyl (4S,5S)-4-benzyloxymethyl-2,2-dimethyl-1,3-dioxolane-4-propanoate, tetrahydrooxepin-2-one and 2,3-O-isopropylidene-d-erythronolactone, respectively, to give the corresponding α-acylphenylacetonitriles. Formation of the methyl enol ethers, condensation with guanidine and deprotection gave the pyrimidine-2,4-diamines. Preliminary assay of the abilities of these compounds to inhibit the growth of TB5 Saccharomyces cerevisiae carrying the DHFR genes from M. tuberculosis, human and yeast indicated that 5-phenyl-6-((3R,4S)-3,4,5-trihydroxypentyl)pyrimidine-2,4-diamine selectively inhibited M. tuberculosis DHFR and had little effect on the human or yeast enzymes.
- El-Hamamsy, Mervat H.R.I.,Smith, Anthony W.,Thompson, Andrew S.,Threadgill, Michael D.
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p. 4552 - 4576
(2008/03/12)
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- Bifunctional acyclic nucleoside phosphonates: synthesis of chiral 9-{3-hydroxy[1,4-bis(phosphonomethoxy)]butan-2-yl} derivatives of purines
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We report herein a general method for the synthesis of new types of chiral acyclic nucleoside four-carbon bisphosphonates. The alkylation of 2-amino-6-chloropurine and adenine was performed with (2S,3S)- or (2R,3R)-1,4-[bis(diisopropoxyphosphoryl)methoxy]]-3-[(methylsulfonyl)oxy]butan-2-yl benzoate. Alkylations provided (2R,3R) or (2S,3S) N9-substituted nucleobases, which were further converted to other derivatives. These conversions included either a modification of the nucleobase or transformation of the bisphosphonate chain. Subsequent deprotection of the diisopropyl esters with bromotrimethylsilane provided the resulting (2R,3R)- or (2S,3S)-bisphosphonic acids.
- Vrbkova, Silvie,Dracinsky, Martin,Holy, Antonin
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p. 2233 - 2247
(2008/02/11)
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- Synthesis of C2-symmetric sulfide and its first application in highly enantioselective synthesis of chiral aziridines
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A C2-symmetric sulfide 6 has been synthesized from cheap L-tartaric acid. It was found that sulfide 6 could perform a tandem reaction with benzyl bromide and tosyl imines to give (2S,3S)-aziridines 9a-9g with good to excellent enantioseletivities (up to 96% ee). Copyright
- Gui, Yuan,Shen,Wang, Hai-Yang,Li, Zhi-Yi,Huang, Zhi-Zhen
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p. 1436 - 1437
(2008/03/18)
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- A new chiral sulfonamide ligand based on tartaric acid: synthesis and application in the enantioselective addition of diethylzinc to aldehydes and ketones
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A new sulfonamide ligand based on l-tartaric acid was synthesized and was employed as a chiral ligand in the enantioselective addition of diethylzinc to aldehydes, giving rise to the best enantiomeric excess up to 83% with 5 mol % of catalyst loading. Moreover, the addition of diethylzinc to ketones can also be achieved with good to excellent enantioselectivities by employing 7 mol % of the catalyst under mild conditions.
- Hui, Ailing,Zhang, Jintang,Fan, Jinmin,Wang, Zhiyong
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p. 2101 - 2107
(2007/10/03)
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- Synthesis and biological evaluation of bis(methoxy-methyl)-7,8-dihydro-[1, 4]dioxino[2,3-g]quinazolines as EGFR tyrosine kinase inhibitors
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A series of 7,8-bis(methoxymethyl)-7,8-dihydro-[1,4]dioxino[2,3-g] quinazolines were prepared and evaluated for their inhibition of phosphorylation of the isolated epidermal growth factor receptor (EGFR) enzyme and for their growth inhibition of the A431 cell line. Among them, compound 3c having a 3-iodophenyl ring was most potent (IC50 = 1.66 nM) against the isolated EGFR enzyme and also showed meaningful potency (GI50 = 1.99 μM) against the A431 cell line, although less than PD153035 (GI50 = 1.03 μM). However, compound 3e as the exact rigidified analogue of Erlotinib (Tarceva) was inferior to the original compound when compared to its reported data.
- Lee, Yong Sup,Seo, Seon Hee,Yang, Beom-Seok,Lee, Jae Yeol
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p. 502 - 505
(2007/10/03)
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- Enantiomerically pure 4-amino-1,2,3-trihydroxybutylphosphonic acids
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(1S,2R,3S)-, (1R,2R,3S)- and (1S,2R,3R)-4-amino-1,2,3- trihydroxybutylphosphonic acids were synthesised. The synthetic strategy involved preparation of the respective 4-azido-2,3-O-isopropylidene-l-threose or -d-erythrose, addition of dialkyl phosphites, separation of C-1 epimeric O,O-dibenzyl phosphonates, the reduction of azides and the removal of the protecting groups. The (2R,3S) and (2R,3R) configurations in the final products were secured by employing diethyl l-tartrate and d-isoascorbic acid as starting materials. The stereochemical course of the addition to the carbonyl groups in 4-azido-2,3-O-isopropylidene-l-threose or -d-erythrose followed that established earlier for 2,3-O-isopropylidene-d-glyceraldehyde and similar (3:1-4:1) diastereoselectivities were achieved.
- Wróblewski, Andrzej E.,G?owacka, Iwona E.
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p. 11930 - 11938
(2007/10/03)
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- Mild and efficient palladium(II)-catalyzed racemization of allenes
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Allenes undergo racemization in the presence of catalytic amounts of Pd(OAc)2/LiBr under mild conditions; the reaction proceeds via a bromopalladation-debromopalladation sequence and tolerates various functional groups.
- Horvath, Attila,Baeckvall, Jan-E.
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p. 964 - 965
(2007/10/03)
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- Enantiocontrolled synthesis of 3-pyrrolines from α-amino allenes
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Cyclization of α-amino allenes in the presence of N-bromosuccinimide afforded pyrrolines in good yields. The products were obtained with high enantiomeric excesses when optically active allenes were used as substrates. The synthesis of a 2,5-dehydroprolinol derivative is also presented. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Horvath, Attila,Benner, Jessica,Baeckvall, Jan-E.
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p. 3240 - 3243
(2007/10/03)
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- Synthesis and structure of 4-R,5-R-[5-(hydroxy-diphenyl-methyl)-2, 2-dimethyl-[1,3] dioxolan-4-yl]-phenyl-methanone, a chiral ligand building block
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A triphenyl analog of taddol, 4-R,5-R-[5-(hydroxy-diphenyl-methyl)-2,2- dimethyl-[1,3]dioxolan-4-yl]-phenyl-methanone, has been synthesized and structurally characterized. This molecule could act as a chiral ligand building block in the creation of tuned taddol analogs. Structural analysis of the title compound reveals that the hydroxyl group is involved in an intramolecular hydrogen bond and does not take part in any intermolecular interaction. Crystal packing is influenced by C-H ... O hydrogen bonding and phenyl ... phenyl interactions. Crystal data: Triclinic, P1 (No. 1), a = 5.9343(4) A, b = 8.2367(17) A, c = 10.987(2) A, α = 88.290(6)°, β= 75.442(4)°, γ = 80.655(6)°, V = 512.86(15) A 3, Z = 1, Dcalc = 1.258 mg/m3. Final residual values were R1 = 0.0407 for 3022 observed data (I > 2s(I) and wR2 = 0.0941 for all 3524 unique data.
- Thompson, Lawrence C.,Knight, Kyle S.,Pennington, William T.
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p. 403 - 407
(2007/10/03)
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- Synthesis of potential thrombin inhibitors. Incorporation of tartaric acid templates as P2 proline mimetics.
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With the objective to prepare novel non-peptidic thrombin inhibitors, bioisosteres of the inhibitory tripeptide D-Phe-Pro-Arg chain have been examined. Thus, the P1 Arg was replaced with p-amidinobenzylamine, an elongated homologue of the same and with 2,
- Dahlgren, Anders,Branalt, Jonas,Kvarnstroem, Ingemar,Nilsson, Ingemar,Musil, Djordje,Samuelsson, Bertil
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p. 1567 - 1580
(2007/10/03)
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- Development of new asymmetric two-center catalysts in phase-transfer reactions
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A new asymmetric two-center phase-transfer catalyst was designed and a catalyst library containing more than 40 new two-center catalysts was constructed. The catalysts were applied in phase-transfer alkylations and Michael additions to afford the correspo
- Shibuguchi, Tomoyuki,Fukuta, Yuhei,Akachi, Yoko,Sekine, Akihiro,Ohshima, Takashi,Shibasaki, Masakatsu
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p. 9539 - 9543
(2007/10/03)
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- Synthesis of novel C2-symmetric and enantiomerically pure bisbenzoxazoles and bisbenzothiazoles derived from L- and D-tartaric acids
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Five pairs of novel C2-symmetric and enantiomerically pure bisbenzoxazoles and a pair of bisbenzothiazoles derived from L- and D-tartaric acids have been synthesized from L- and D-2,3-O-isopropylidenetartaric dichlorides and o-aminophenol derivatives or o-aminothiophenol, respectively, in two- or one-step reactions. The mechanism for the formation of bisbenzoxazoles and bisbenzothiazoles was suggested. The UV and 1H NMR spectra showed that no coordination between the bisbenzoheterazoles and Cu(I) or Ni(II) cations occurred due to the lack of a sufficiently basic nitrogen donor atom in the benzoheterazole moiety.
- Jiao, Peng,Xu, Jiaxi,Zhang, Qihan,Choi, Michael C.K.,Chan, Albert S.C.
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p. 3081 - 3088
(2007/10/03)
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- Helical twist sense bias in oligo(phenylene ethynylene)s induced by an optically active flexible tether
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(equation presented) A series of tethered phenylene ethynylene oligomers, which undergo a solvent-dependent conformational transition from a random coil to a helix, has been synthesized. The use of trimethylsilyl ether protecting groups on the (+)-tartaric acid-derived tether results in the formation of helices with a large twist sense bias. In contrast, an isopropylidene ketal protecting group or no protecting group is not only ineffective at helical discrimination but may even inhibit helix formation.
- Gin, Mary S.,Moore, Jeffrey S.
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p. 135 - 138
(2007/10/03)
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- Efficient asymmetric synthesis of cis-2-methylcyclopropanecarboxylic acid
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We have developed a versatile method for the synthesis of enantiomerically pure cis-2-methylcyclopropanecarboxylic acid (-)-2, a component of curacin A, and its enantiomer, (+)-2. Double-asymmetric Simmons-Smith cyclopropanation of the dienes 5 and 9 derived from diethyl L-tartrate proceeded with excellent diastereofacial selectivity (>99% de) to give the dicyclopropanes 6 and 10, which were converted to both enantiomers of 2.
- Onoda, Toshihiko,Shirai, Ryuichi,Kawai, Nobuyuki,Iwasaki, Shigeo
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p. 13327 - 13338
(2007/10/03)
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- Phosphine-borane complexes; Direct use in asymmetric catalysis
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An easy and soft method of decomplexation of phosphine-borane complexes, by DABCO, allows its use in situ in asymmetric catalytic hydrogenation of double bonds with metal phosphine complexes.
- Brisset,Gourdel,Pellon,Le Corre
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p. 4523 - 4526
(2007/10/02)
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- Synthesis and the Absolute Configuration of Panaxacol
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Panaxacol, a polyacetylene isolated from the callus of Panax ginseng, was synthesized from D-(-)-diethyl tartrate.The absolute configuration of panaxacol was determined to be 9R,10R.
- Fujimoto, Yasuo,Satoh, Mitsuru,Takeuchi, Naoki,Kirisawa, Makoto
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p. 1619 - 1622
(2007/10/02)
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- SYNTHESIS OF 12-HYDROPEROXYEICOSATETRAENOIC ACID (12-HPETE). ON THE STEROCHEMISTRY IN THE CONVERSION OF 12(S)-HETE TO 12-HPETE
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12(S)-hydroxyeicosatetraenoic acid methyl ester 1 was synthesized. 1 was converted to phosphite 17 which upon treatment with hydrogen peroxide afforded the corresponding hydroperoxide 18 (12-HPETE methyl ester) with partially retained configuration.
- Nagata, Ryu,Kawakami, Masayuki,Matsuura, Teruo,Saito, Isao
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p. 2817 - 2820
(2007/10/02)
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- Enanthioselective Phase-Transfer Catalysis by Optically Active Crown Ethers
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1,2-Bis(hydroxymethyl)-15-crown-5 (1a), its dibenzyl ether (1b), and a series of esters with substituted benzoic acid (3) were probed as enanthioselective phase-transfer catalysts.Optical yields were observed in epoxidations of unsaturated ketones by hypochlorite and in cyanide additions to such compounds.The maximum ee value was 45percent.Polar side groups of the optically active crown ethers proved to be vital for enanthiomeric excesses.
- Dehmlow, Eckehard V.,Sauerbier, Christiane
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p. 181 - 186
(2007/10/02)
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- STEREOCONTROLLED TOTAL SYNTHESIS OF THE MACROCYCLIC LACTONE (-)-ASPICILIN
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The essential features of the enantiocontrolled total synthesis of (-)-aspicilin are the strategic use of the photochemical rearrangement of α,β-epoxy diazomethyl ketones to 4-hydroxyalkenoates (Scheme 1) and the stereochemical control of the Sharpless epoxidation, α,ο functionalization of an alkynol using potassium 3-aminopropylamine (KAPA) as acetylene zipper, coupling between C7 and C8 by means of a Wittig reaction and lactonization by using 2,6-dichlorobenzoyl chloride.
- Waanders, P.P.,Thijs, L.,Zwanenburg, B.
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p. 2409 - 2412
(2007/10/02)
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- THE CHEMISTRY OF SILYLATED KETENE ACETALS: AN EFFICIENT STEREOCONTROLLED SYNTHESIS OF N-BENZOYL L-DAUNOSAMINE
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N-Benzoyl L-daunosamine was synthesized with high stereoselectivity utilizing a 1,3-addition of ketene silyl acetal (3a) to the chiral nitrone, (Z)-((4R)-trans-2,2,5-trimethyl-1,3-dioxolan-4-yl)methylene((1S)-1-phenylethyl)amine N-oxide (4c) accompanied by a silyl group-transfer in acetonitrile under mild conditions.
- Kita, Yasuyuki,Itoh, Fumio,Tamura, Osamu,Ke, Ya Yuan,Tamura, Yasumitsu
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p. 1431 - 1434
(2007/10/02)
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