- A Bifunctional Copper Catalyst Enables Ester Reduction with H2: Expanding the Reactivity Space of Nucleophilic Copper Hydrides
-
Employing a bifunctional catalyst based on a copper(I)/NHC complex and a guanidine organocatalyst, catalytic ester reductions to alcohols with H2 as terminal reducing agent are facilitated. The approach taken here enables the simultaneous activation of esters through hydrogen bonding and formation of nucleophilic copper(I) hydrides from H2, resulting in a catalytic hydride transfer to esters. The reduction step is further facilitated by a proton shuttle mediated by the guanidinium subunit. This bifunctional approach to ester reductions for the first time shifts the reactivity of generally considered "soft"copper(I) hydrides to previously unreactive "hard"ester electrophiles and paves the way for a replacement of stoichiometric reducing agents by a catalyst and H2.
- Kaicharla, Trinadh,Ngoc, Trung Tran,Teichert, Johannes F.,Tzaras, Dimitrios-Ioannis,Zimmermann, Birte M.
-
supporting information
p. 16865 - 16873
(2021/10/20)
-
- Oxoammonium-Mediated Allylsilane–Ether Coupling Reaction
-
A new C(sp3)?H functionalization reaction consisting of the oxidative α-allylation of allyl- and benzyl- methyl ethers has been developed. The C?C coupling could be carried out under mild conditions thanks to the use of cheap and green oxoammonium salts. The scope of the reaction was studied over 27 examples, considering the nature of the substituents on the two coupling partners.
- Carlet, Federica,Bertarini, Greta,Broggini, Gianluigi,Pradal, Alexandre,Poli, Giovanni
-
supporting information
p. 2162 - 2168
(2021/04/02)
-
- Manganese-catalysed transfer hydrogenation of esters
-
Manganese catalysed ester reduction using ethanol as a hydrogen transfer agent in place of dihydrogen is reported. High yields can be achieved for a range of substrates using 1 mol% of a Mn(i) catalyst, with an alkoxide promoter. The catalyst is derived from a tridentate P,N,N ligand.
- Oates, Conor L.,Widegren, Magnus B.,Clarke, Matthew L.
-
supporting information
p. 8635 - 8638
(2020/08/21)
-
- α-Lithiobenzyloxy as a Directed Metalation Group in ortho-Lithiation Reactions
-
The α-lithiobenzyloxy group, easily generated from aryl benzyl ethers by selective α-lithiation with t-BuLi at low temperature, behaves as a directed metalation group (DMG) providing a direct access to o-lithiophenyl α-lithiobenzyl ethers. This ortho-directing effect is reinforced in substrates bearing an additional methoxy group at the meta position. The generated dianions can be reacted with a selection of electrophiles including carboxylic esters and dihalosilanes or germanes, which afford interesting benzofuran, sila(germa)dihydrobenzofuran, and silachroman derivatives from simple aryl benzyl ethers.
- Sedano, Carlos,Velasco, Rocío,Feberero, Claudia,Suárez-Pantiga, Samuel,Sanz, Roberto
-
supporting information
p. 6365 - 6369
(2020/08/24)
-
- Fumarate related impurity and preparation method and application thereof (by machine translation)
-
The preparation method of the related impurities comprises the following steps: No.No.No. STR8No.No. wherein the (I) preparation method, of ,R the related impurities is. shown, in the specification, and the preparation method of, the 1 present, application, further, discloses, the preparation method, and of the related impurities. (by machine translation)
- -
-
Paragraph 0091-0094
(2020/02/04)
-
- Tuning Cu Overvoltage for a Copper-Telluride System in Electrocatalytic Water Reduction and Feasible Feedstock Conversion: A New Approach
-
Highly efficient and earth-abundant elements capable of water reduction by electrocatalysis and are attractive for the sustainable generation of fuels. Among the earth-abundant metals, copper is one of the cheapest but often the most neglected choice for the hydrogen evolution reaction (HER) due to its high overvoltage. Herein, for the first time we have tuned the overpotential of copper by tellurizing it by two different methodologies, viz. hydrothermal and wet chemical methods, which form copper telluride nanochains and aggregates. The application of copper telluride as an electrocatalyst for the HER gave fruitful results in terms of both activity and stability. The hydrothermally synthesized catalyst Cu2-xTe/hyd shows a low overpotential (347 mV) at 10 mA cm-2 toward the HER. In addition, the catalyst showed a very low charge transfer resistance (Rct) of 24.4 ω and, as expected, Cu2-xTe/hyd exhibited a lower Tafel slope value of 188 mV/dec in comparison to Cu2-xTe/wet (280 mV/dec). A chronoamperometry study reveals the long-term stability of both catalysts even up to 12 h. The Faradaic efficiency of Cu2-xTe/hyd was calculated and found to be 95.06percent by using gas chromatographic (GC) studies. Moreover, with the idea of utilizing produced hydrogen (H2) from electrocatalysis, for the first time we have carried out feedstock conversion to platform chemicals in water under eco-friendly green conditions. We have chosen cinnamaldehyde, 2-hydroxy-1-phenylethanone, 4-(benzyloxy)benzaldehyde, and 2-(3-methoxyphenoxy)-1-phenylethanone (β-O-4) as model compounds for feedstock conversion by hydrogenation and/or hydrogenolysis reactions in aqueous medium using external hydrogen pressure. This protocol could also be scaled up for large-scale conversion and the catalyst is likely to find industrial application since it requires an inexpensive catalyst and an easily available, mild reducing agent. The robustness of the developed catalyst is proven by recyclability experiments and its possibility of use in real-life applications.
- Johny, Jinta Merlin,Karthick, Kannimuthu,Kumaravel, Sangeetha,Kundu, Subrata,Sankar, Selvasundarasekar Sam,Thiruvengetam, Prabaharan
-
supporting information
(2020/08/12)
-
- Combined KOH/BEt3Catalyst for Selective Deaminative Hydroboration of Aromatic Carboxamides for Construction of Luminophores
-
The selective catalytic C-N bond cleavage of amides into value-added amine products is a desirable but challenging transformation. Molecules containing iminodibenzyl motifs are prevalent in pharmaceutical molecules and functional materials. Here we established a combined KOH/BEt3 catalyst for deaminative hydroboration of acyl-iminodibenzyl derivatives, including nonheterocyclic carboxamides, to the corresponding amines. This novel transition-metal-free methodology was also applied to the construction of Clomipramine and luminophores.
- Li, Jinshan,Wang, Jiali,Yang, Jianguo,Yao, Wubing,Zhong, Aiguo
-
p. 8086 - 8090
(2020/11/03)
-
- A General Method for Photocatalytic Decarboxylative Hydroxylation of Carboxylic Acids
-
A general and practical method for decarboxylative hydroxylation of carboxylic acids was developed through visible light-induced photocatalysis using molecular oxygen as the green oxidant. The addition of NaBH4 to in situ reduce the unstable peroxyl radical intermediate much broadened the substrate scope. Different sp3 carbon-bearing carboxylic acids were successfully employed as substrates, including phenylacetic acid-type substrates, as well as aliphatic carboxylic acids. This transformation worked smoothly on primary, secondary, and tertiary carboxylic acids.
- Khan, Shah Nawaz,Zaman, Muhammad Kashif,Li, Ruining,Sun, Zhankui
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p. 5019 - 5026
(2020/05/01)
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- New convergent one pot synthesis of amino benzyl ethers bearing a nitrogen-containing bicycle
-
We report herein a new convergent one pot method for the synthesis of amino benzyl ethers containing a bicyclic amine, derived from different substituted benzyl alcohols and bicyclic amino alcohols such as tropine, pseudotropine, and 3-quinuclidinol, using chlorotrimethylsilane and sodium iodide. In order to avoid the competitive reaction with the nitrogen atom, a solution of the separately prepared alkoxide of tropine, pseudotropine, and 3-quinuclidinol was added to the preformed substituted benzyl iodides and allowed to reflux at 90 °C for 15 h under nitrogen atmosphere. This method provides an efficient alternative of the preparation of amino benzyl ethers in organic synthesis with good yields in comparison with existed methods.
- López, Jhon J.,Pérez, Edwin G.
-
p. 715 - 723
(2019/02/19)
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- Controlled Reduction of Carboxamides to Alcohols or Amines by Zinc Hydrides
-
New protocols for controlled reduction of carboxamides to either alcohols or amines were established using a combination of sodium hydride (NaH) and zinc halides (ZnX2). Use of a different halide on ZnX2 dictates the selectivity, wherein the NaH-ZnI2 system delivers alcohols and NaH-ZnCl2 gives amines. Extensive mechanistic studies by experimental and theoretical approaches imply that polymeric zinc hydride (ZnH2)∞ is responsible for alcohol formation, whereas dimeric zinc chloride hydride (H?Zn?Cl)2 is the key species for the production of amines.
- Ong, Derek Yiren,Yen, Zhihao,Yoshii, Asami,Revillo Imbernon, Julia,Takita, Ryo,Chiba, Shunsuke
-
supporting information
p. 4992 - 4997
(2019/03/13)
-
- MODULATORS OF ESTROGEN RECEPTOR PROTEOLYSIS AND ASSOCIATED METHODS OF USE
-
The present disclosure relates to bifunctional compounds, which find utility as modulators of estrogen receptor (target protein). In particular, the present disclosure is directed to bifunctional compounds, which contain on one end a cereblon, Von Hippel-Lindau ligase-binding moiety, Inhibitors of Apotosis Proteins, or mouse double-minute homolog 2 ligand, which binds to the respective E3 ubiquitin ligase, and on the other end a moiety which binds the target protein, such that the target protein is placed in proximity to the ubiquitin ligase to effect degradation (and inhibition) of target protein. The present disclosure exhibits a broad range of pharmacological activities associated with degradation/inhibition of target protein. Diseases or disorders that result from aggregation or accumulation of the target protein are treated or prevented with compounds and compositions of the present disclosure.
- -
-
Paragraph 00475
(2018/08/20)
-
- COMPOSITIONS AND METHODS FOR REDUCTION OF KETONES, ALDEHYDES AND IMINIUMS, AND PRODUCTS PRODUCED THEREBY
-
A method of producing an alcohol, comprises reducing an aldehyde or a ketone with a hydridosilatrane. The reducing is carried out with an activator.
- -
-
Paragraph 0076-0077
(2018/01/20)
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- Benzofuran compound and its preparation, use (by machine translation)
-
The invention relates to a benzofuran compound and its preparation, use, its structural formula such as formula (I) as shown: Wherein R1 , R2 , R4 Are selected from hydrogen, C1 - C5 Alkyl, nitro, halogen, ester, hydroxy, amino, amide base or alkoxyl; R3 Hydrogen, C1 - C5 Alkyl, benzyl, aromatic or heteroaromatic group. The invention also relates to the benzofuran compounds in inhibiting the application of gram-positive to be used repeatedly. The invention relates to 3 - oxime substituted benzene and furan structure aromatic ring as the center, the establishment and optimize the preparation method of the compound, and on the preparation of novel compound of the bacteriostatic screening experiment, through initial bacteriostatic test to confirm that preparation compound has broad-spectrum bacteriostatic activity. (by machine translation)
- -
-
Paragraph 0060-0061
(2017/08/18)
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- Scandium as a pre-catalyst for the deoxygenative allylation of benzylic alcohols
-
Scandium triflate is an effective pre-catalyst for the deoxygenative allylation of benzylic alcohols with a narrow substrate window. The reaction is shown to proceed through a "hidden Br?nsted acid" mechanism. The reaction is efficient provided that the aryl group is neither too electron rich nor too electron poor. It is shown that this allows useful selectivity. The reaction also works for benzyhydryl alcohols with broader scope. The reaction may also be catalysed by Nafion.
- ?oli?, Ivan,Seankongsuk, Pattarakiat,Loh, Joanna Kejun,Vilaivan, Tirayut,Bates, Roderick W.
-
supporting information
p. 119 - 123
(2017/12/27)
-
- Highly efficient reduction of carbonyls, azides, and benzyl halides by NaBH4 in water catalyzed by PANF-immobilized quaternary ammonium salts
-
A series of polyacrylonitrile fiber-supported quaternary ammonium salts (PANF-QAS) were prepared and applied to the catalytic reduction of aldehydes, ketones, azides, and benzyl halides in water using NaBH4 as the reducing reagent in a highly efficient, economic, and environmentally benign way. The structure-activity relationships were investigated, which showed that the catalysts made up of quaternary ammonium salts with longer alkyl chains, larger cationic radii and better lipophilicity speed up the reduction reaction to afford the products in excellent yield. Moreover, the optimized catalyst can be applied to the reduction of 1-naphthaldehyde in a continuous flow process with outstanding reactivity and recyclability.
- Du, Jianguo,Xu, Gang,Lin, Huikun,Wang, Guangwei,Tao, Minli,Zhang, Wenqin
-
supporting information
p. 2726 - 2735
(2016/05/24)
-
- New synthesis method of two enantiomers of 4-(4-(benzyloxy)phenyl)-2-hydroxybutyric acid
-
The invention discloses a new synthesis method of two enantiomers of 4-(4-(benzyloxy)phenyl)-2-hydroxybutyric acid. The invention adopts cheap and easily available p-hydroxy benzaldehyde and (R)-(+)-2, 2-dimethyl-1, 3-dioxolane-4-formaldehyde as initial raw materials to conduct total synthesis study on brand new compounds (R)-4-(4-(benzyloxy)phenyl)-2-hydroxybutyric acid and (S)-4-(4-(benzyloxy)phenyl)-2-benzyl hydroxybutyric acid. The invention uses an asymmetric synthesis method to synthesize two molecules by one route, fills the blank, and provides convenience for future scientific research.
- -
-
Paragraph 0030; 0034; 0035
(2017/02/28)
-
- Palladium Catalysis Enables Benzylation of α,α-Difluoroketone Enolates
-
A palladium-catalyzed decarboxylative benzylation reaction of α,α-difluoroketone enolates is reported, in which the key C(α)?C(sp3) bond is generated by reductive elimination from a palladium intermediate. The transformation provides convergent access to α-benzyl-α,α-difluoroketone-based products, and should be useful for accessing biological probes.
- Yang, Ming-Hsiu,Hunt, Jordan R.,Sharifi, Niusha,Altman, Ryan A.
-
supporting information
p. 9080 - 9083
(2016/07/26)
-
- Silatrane as a Practical and Selective Reagent for the Reduction of Aryl Aldehydes to Benzylic Alcohols
-
Hydrosilanes are cheap, readily available substrates, yet they do not see as extensive use for simple carbonyl reductions as borohydrides. Hydrosilane reducing agents broadly fall into one of two general categories: either a) they are easy to handle and require expensive and/or hazardous additives, or b) they are difficult and/or dangerous to handle. This work details the discovery of mild and functional group compatible conditions utilizing hydrosilatrane for the selective reduction of aryl aldehydes to benzylic alcohols without unwanted formation of ethers or deoxygenated products. This method offers significant advances in silane reductions as silatrane is an air- and moisture-stable yet relatively reactive reducing agent that can be used in benchtop open air reactions.
- Skrypai, Vladislav,Hurley, Joseph J. M.,Adler, Marc J.
-
supporting information
p. 2207 - 2211
(2016/05/09)
-
- Complete synthesis method of natural product Nostosin B
-
The invention discloses a complete synthesis method of a natural product Nostosin B, and belongs to the technical field of organic synthesis. According to the synthesis method, complete synthesis of the natural product Nostosin B is completed by natural amino acid L-isoleucine, arginine and a non-natural compound 2 which are cheap and easy to obtain through peptide coupling and using of various of functional group protecting groups. The natural product Nostosin B is prepared through the complete synthesis method for the first time. The synthesis method has the advantages of being simple, convenient, feasible, easy to operate and high in yield.
- -
-
Paragraph 0009; 0046; 0047
(2017/01/17)
-
- Highly chemoselective hydrogenation of active benzaldehydes to benzyl alcohols catalyzed by bimetallic nanoparticles
-
By using novel Pd/Ni bimetallic nanoparticles as a catalyst, the active benzaldehydes were hydrogenated to the corresponding benzyl alcohols as unique products in practical quantitative yields. The undesired catalytic hydrogenolysis of the benzyl alcohol was inhibited completely. By using this hydrogenation as a key step, the total synthesis of the natural product gastrodin was achieved with less total steps and a higher total yield.
- Liu, Chulong,Bao, Hailin,Wang, Dingsheng,Wang, Xinyan,Li, Yadong,Hu, Yuefei
-
p. 6460 - 6462
(2015/11/16)
-
- Beyond the affinity for protein kinase C: Exploring 2-phenyl-3-hydroxypropyl pivalate analogues as C1 domain-targeting ligands
-
Over the past fifteen years, we reported the design and synthesis of different series of compounds targeting the C1 domain of protein kinase C (PKC) that were based on various templates. Out of the pivalate templates, 2-[4-(benzyloxy)phenyl]-3-hydroxypropyl pivalate (compound 1) emerged as the most potent and promising PKCα ligand, showing a Ki value of 0.7 μM. In the present contribution our efforts are aimed at better understanding which structural modifications of the pivalate template are allowed for its affinity to the C1 domain of PKC to be preserved or increased. To this aim, thirteen novel analogues of 1 were designed and their interaction with the target was evaluated in silico. Designed compounds were then prepared and fully characterized as well as their affinity for the α and δ isoforms of PKC evaluated. Additionally, in order to investigate the role of chirality in the ligand-target interaction, the pure enantiomers of the most interesting PKC ligands were prepared and their affinity for PKC isoforms was determined. Results from our study revealed that: i) the presence of the ester function seems to be essential for the ligand-target interaction; ii) only a few structural modifications at the ester group are allowed for the C1 domain affinity to be preserved; and iii) the [3H]PDBu replacement experiments showed that the C1 domain of PKC does not exhibit enantiopreference for the pure stereoisomers of tested compounds. Altogether our observations provide further insights into the ligand-target interactions of the PKC C1 domain and represent a step-forward in future development of more specific and effective PKC ligands. This journal is
- Rossi, Daniela,Talman, Virpi,Genn?s, Gustav Boije Af,Marra, Annamaria,Picconi, Pietro,Nasti, Rita,Serra, Massimo,Ann, Jihyae,Amadio, Marialaura,Pascale, Alessia,Tuominen, Raimo K.,Yli-Kauhaluoma, Jari,Lee, Jeewoo,Collina, Simona
-
supporting information
p. 547 - 554
(2015/04/27)
-
- Strategies for large-scale synthesis of coelenterazine for in vivo applications
-
A new application of two Negishi-type coupling reactions for the synthesis of coelenterazine is reported. The synthesis of coelenterazine in high purity on a gram scale will enable numerous approaches to bioluminescence imaging and possibly photodynamic therapy of deep-seated tumors. Coelenterazine is the substrate for several luciferases, among them Gaussia luciferase (gLuc). This synthesis starts with pyrazin-2-amine and uses inexpensive starting materials and catalysts. Georg Thieme Verlag Stuttgart New York.
- Shrestha, Tej B.,Troyer, Deryl L.,Bossmann, Stefan H.
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p. 646 - 652
(2014/03/21)
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- A mild and efficient flow procedure for the transfer hydrogenation of ketones and aldehydes using hydrous zirconia
-
A flow chemistry Meerwein-Ponndorf-Verley (MPV) reduction procedure using partially hydrated zirconium oxide via a machine-assisted approach is reported. The heterogeneous reductive system could be applied to a wide range of functionalized substrates, allowing clean and fast delivery of the alcohol products within a few minutes (6-75 min). In three examples the system was scaled to deliver 50 mmol of product.
- Battilocchio, Claudio,Hawkins, Joel M.,Ley, Steven V.
-
supporting information
p. 2278 - 2281
(2013/06/05)
-
- Pd/C-mediated depropargylation of propargyl ethers/amines in water
-
Propargyl ethers and amines are effectively depropargylated to the parent alcohols or amines via a C-O/C-N bond cleavage catalyzed by 10% Pd/C in water. This simple, facile, and inexpensive methodology could be utilized for the selective removal of propargyl groups from a variety of aryl ethers and amines.
- Rambabu,Bhavani,Swamy, Nalivela Kumara,Basaveswara Rao,Pal, Manojit
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p. 1169 - 1173
(2013/04/10)
-
- Discrete iron complexes for the selective catalytic reduction of aromatic, aliphatic, and α,β-unsaturated aldehydes under water-gas shift conditions
-
Iron-catalyzed reductions: Selective iron-catalyzed reduction of aldehydes with hydrogen generated in situ by the water-gas shift reaction is presented (see scheme). The generality and selectivity of this mild procedure are demonstrated by the efficient reduction of various aromatic, aliphatic and α,β-unsaturated aldehydes.
- Tlili, Anis,Schranck, Johannes,Neumann, Helfried,Beller, Matthias
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p. 15935 - 15939
(2013/02/21)
-
- A novel oxidative transformation of alcohols to nitriles: An efficient utility of azides as a nitrogen source
-
An efficient methodology to oxidize benzylic and cinnamyl alcohols to their corresponding nitriles in excellent yields has been developed. This methodology employs DDQ as an oxidant and TMSN3 as a source of nitrogen in the presence of a catalytic amount of Cu(ClO4)2·6H 2O.
- Rokade, Balaji V.,Malekar, Sanjeev K.,Prabhu, Kandikere Ramaiah
-
supporting information; body text
p. 5506 - 5508
(2012/07/03)
-
- FAMILY OF ARYL, HETEROARYL, O-ARYL AND O-HETEROARYL CARBASUGARS
-
The present invention relates to a compound of the following formula (I): as well as its process of preparation, pharmaceutical and cosmetics composition comprising it and use thereof, notably as an inhibitor of the sodium-dependent glucose co-transporter, such as SGLTl, SGLT2 and SGLT3, in particular in the treatment or prevention of diabetes, and more particularly type-II diabetes, diabetes-related complications, such as arthritis of the lower extremities, cardiac infarction, renal insufficiency, neuropathy or blindness, hyperglycemia, hyperinsulinemia, obesity, hypertriglyceridemia, X syndrome and arteriosclerosis, as well as for its use as an anticancer, anti-infective, anti-viral, anti-thrombotic or anti- inflammatory drug, or for lightening, bleaching, depigmenting the skin, removing blemishes from the skin, particularly age spots and freckles, or preventing pigmentation of the skin.
- -
-
Page/Page column 66-67
(2012/12/13)
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- MATRIX METALLOPROTEINASE INHIBITORS
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This invention also relates to pharmacological compositions containing the compounds of the present invention, and methods of treating asthma, rheumatoid arthritis, COPD, rhinitis, osteoarthritis, psoriatic arthritis, psoriasis, pulmonary fibrosis, pulmonary inflammation, acute respiratory distress syndrome, perodontitis, multiple sclerosis, gingivitis, atherosclerosis, dry eye, neointimal proliferation, which leads to restenosis and ischemic heart faliure, stroke, renal diseases, tumor metastasis, and other inflammatory disorders characterized by over-expression and over-activation of matrix metalloproteinase using the compounds.
- -
-
Page/Page column 46-47
(2012/04/10)
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- Total synthesis of naturally occurring furan compounds 5-{[(4- hydroxybenzyl)oxy]methyl}-2-furaldehyde and pichiafuran C
-
The synthesis of the natural furan derivatives 5-{[(4-hydroxybenzyl)oxy] methyl}-2-furaldehyde and pichiafuran C is described. Diverse alternative synthetic approaches were developed for the preparation of these natural products. They were prepared through an etherification reaction of the key furan precursor 5-(hydroxymethyl)-2-furaldehyde (HMF), which can be readily obtained from d-fructose, d-glucose, or sucrose, with the corresponding alcohols. 5-{[(4-Hydroxybenzyl)oxy]methyl}-2-furaldehyde was not only obtained in a two-step methodology but also by a biomimetic single-step synthesis. Similarly, pichiafuran C was prepared by three different syntheses, each one by a two-step procedure, also including a biomimetic approach. Georg Thieme Verlag Stuttgart.
- Quiroz-Florentino, Hector,Hernandez-Benitez, R. Israel,Avina, Judit A.,Burgueno-Tapia, Eleuterio,Tamariz, Joaquin
-
experimental part
p. 1106 - 1112
(2011/06/20)
-
- ALKANOIC ACID DERIVATIVES AND THEIR THERAPEUTIC USE AS HDAC INHIBITORS
-
The invention related to alkanoic acid derivatives of Formula (IIa) and (IIb). These compounds of the invention were found to have activity as HDAC inhibitors.
- -
-
Page/Page column 99-100
(2010/08/05)
-
- Synthesis and optimization of antitubercular activities in a series of 4-(aryloxy)phenyl cyclopropyl methanols
-
A series of [4-(aryloxy)phenyl]cyclopropyl methanones were synthesized by reaction of different benzyl alcohols with 4-chloro-4′-fluorobutyrophenone in DMF in the presence of NaH/TBAB. The methanones were further reduced to respective methanols. The antitubercular activity of these compounds was evaluated in vitro against Mycobacterium tuberculosis H37Rv. Compounds 19, 21, 35, 36 and 37 have shown minimum inhibitory concentration (MIC) of 3.12 μg/mL, while compounds 14, 25 and 18 have shown MIC of 1.56 μg/mL and 0.78 μg/mL respectively. One of the compounds, cyclopropyl-4-[4-(2-piperidin-1- yl-ethoxy)benzyloxy]phenyl}methanol (36) showed 98% killing of intracellular bacilli in mouse bone marrow derived macrophages and was active against MDR, XDR and rifampicin clinical isolates resistant strains with MIC 12.5 μg/mL. Compound 36 was orally active in vivo in mice against M. tuberculosis H37Rv with an increase in MST by 6 days with 1 log reduction in the bacillary density in lungs as compared to control on 30th day after infection.
- Bisht, Surendra S.,Dwivedi, Namrata,Chaturvedi, Vinita,Anand, Namrata,Misra, Mridul,Sharma, Rahul,Kumar, Brijesh,Dwivedi, Richa,Singh, Shyam,Sinha, Sudhir Kumar,Gupta, Versha,Mishra,Dwivedi, Anil K.,Tripathi, Rama P.
-
scheme or table
p. 5965 - 5978
(2011/01/13)
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- Microwave-assisted rapid and efficient deprotection and direct esterification and silylation of MOM and EOM ethers catalyzed by [Hmim][HSO 4] as a Bronsted acidic ionic liquid
-
1-Methylimidazolium hydrogensulfate, [Hmim] [HSO4], a Bronsted acidic room temperature ionic liquid, is used as a catalyst and reaction medium for facile and ecofriendly deprotection of methoxymethyl (MOM) and ethoxymethyl (EOM) ethers to their corresponding alcohols under thermal conditions (Δ) and microwave irradiation (MW). Furthermore, one-pot interconversion to the respective acetates and trimethylsilyl (TMS) ethers was also achieved. Springer-Verlag 2010.
- Mohammadpoor-Baltork, Iraj,Moghadam, Majid,Tangestaninejad, Shahram,Mirkhani, Valiollah,Khosropour, Ahmad Reza,Mirjafari, Arsalan
-
experimental part
p. 1083 - 1088
(2012/06/18)
-
- Counterattack mode differential acetylative deprotection of phenylmethyl ethers: Applications to solid phase organic reactions
-
A counterattack protocol for differential acetylative cleavage of phenylmethyl ether has been developed. The phenylmethyl moiety is liberated as benzyl bromide that is isolated and reused providing advantages in terms of waste minimization/utilization and atom economy. The applicability of this methodology has been extended for solid phase organic reactions with the feasibility of reuse of the solid support.
- Chakraborti, Asit K.,Chankeshwara, Sunay V.
-
supporting information; experimental part
p. 1367 - 1370
(2009/07/04)
-
- Silica triflate as a new, efficient, and reusable reagent for the chemoselective silylation of alcohols and phenols and deprotection of silyl ethers
-
Silica triflate was easily prepared via reaction of silica gel and trifluoromethane sulfonyl chloride at room temperature. This compound can be employed as an efficient and reusable reagent for the chemoselective silylation of alcohols and phenols in solution and under solvent-free conditions. This reagent also effectively catalyzed the deprotection of silyl ethers in refluxing methanol.
- Shirini,Marjani,Nahzomi, H. Taherpour,Zolfigol
-
p. 168 - 177
(2008/12/22)
-
- Traceless solid-phase synthesis of hydroxylated cyclopentenones
-
Intramolecular nitrone-alkene cycloadditions on solid phase can be performed using polymer-bound hydroxylamine. Condensation of this reagent with sugar derived 4-pentenals followed by N-O cleavage, quaternization of the amine thus produced, and finally oxidative elimination of the amino group detaches the chiral hydroxylated cyclopentenones from the polymer. The natural antibiotic pentenomycin I was prepared in this way.
- Stathakis, Christos I.,Gallos, John K.
-
scheme or table
p. 6804 - 6806
(2009/04/07)
-
- New PPARγ ligands based on 2-hydroxy-1,4-naphthoquinone: Computer-aided design, synthesis, and receptor-binding studies
-
FlexX-based molecular docking study was employed to identify 2-hydroxy-1,4-naphthoquinone as a new 'acidic head group' for the design of a novel series of PPARγ ligands. To provide the proof of concept, designed molecules were synthesized and evaluated in a standard radioligand-binding assay. Out of eight molecules, four were found to bind to the murine PPARγ with IC50 ranging from 0.2 to 56.2 μM as compared to standard pioglitazone, with IC50 of 0.7 μM.
- Sundriyal, Sandeep,Viswanad, Bhoomi,Bharathy, Elumalai,Ramarao, Poduri,Chakraborti, Asit K.,Bharatam, Prasad V.
-
scheme or table
p. 3192 - 3195
(2009/04/06)
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- H3PW12O40 - A selective, environmentally benign, and reusable catalyst for the preparation of methoxymethyl and ethoxymethyl ethers and their deprotections under mild conditions
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Different types of primary and secondary alcohols were efficiently transformed to their corresponding methoxymethyl (MOM) and ethoxymethyl (EOM) ethers in the presence of catalytic amounts of H3PW 12O40 at room temperature under solvent-free conditions. Selective protection of primary and secondary alcohols in the presence of phenols and tertiary alcohols was achieved by this method. Deprotection of these ethers to their parent alcohols was also performed using this catalyst in ethanol under reflux conditions. We have also found that primary and secondary MOM- and EOM-ethers are selectively deprotected in the presence of phenolic and tertiary ones, methyl and benzyl ethers, esters, and trimethylsilyl ethers by this catalyst. The notable advantages of this protocol are high yields, short reaction times, easy work-up, non-toxicity, easy availability and handling, eco-friendly, and reusability of the catalyst.
- Mohammadpoor-Baltork, Iraj,Moghadam, Majid,Tangestaninejad, Shahram,Mirkhani, Valiollah,Mirjafari, Arsalan
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p. 831 - 840
(2008/12/21)
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- Soluble and polymer-supported 2- and 3-benzylated furans for the preparation of α,β-ethylenic carbonyl compounds
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Soluble and polymer-supported 2- and 3-benzylated furans were subjected to a sequence involving a Diels-Alder reaction with α,β-acetylenic carbonyl compounds, a Michael addition, and a subsequent retro-Diels-Alder reaction to yield olefinic compounds. On solid support, this traceless strategy is advantageous since pure compounds were released in the thermal cycloreversion step. The fur-2-ylated resin allowed a highly diastereoselective synthesis.
- Albert, Sébastien,Soret, Adrien,Blanco, Luis,Deloisy, Sandrine
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p. 2888 - 2900
(2007/10/03)
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- A convenient and general iron-catalyzed hydrosilylation of aldehydes
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A general and highly chemoselective hydrosilylation of aldehydes using iron catalysts is reported. Fe(OAc)2 in the presence of tricyclohexylphosphine as ligand and polymethylhydrosiloxane (PMHS) as an economical hydride source forms an efficient catalyst system for the hydrosilylation of a variety of aldehydes. Aryl, heteroaryl, alkyl and α,β-unsaturated aldehydes are successfully reduced to the corresponding primary alcohols. Broad substrate scope and high tolerance against several functional groups make the process synthetically useful.
- Shaikh, Nadim S.,Junge, Kathrin,Beller, Matthias
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p. 5429 - 5432
(2008/09/19)
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- Pd-C-induced catalytic transfer hydrogenation with triethylsilane
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(Chemical Equation Presented) In situ generation of molecular hydrogen by addition of triethylsilane to palladium-charcoal catalyst results in rapid and efficient reduction of multiple bonds, azides, imines, and nitro groups, as well as benzyl group and allyl group deprotection under mild, neutral conditions.
- Mandal, Pijus K.,McMurray, John S.
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p. 6599 - 6601
(2008/02/10)
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- Selective cleavage of allyl and propargyl ethers to alcohols catalyzed by Ti(O-i-Pr)4/MXn/Mg
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(Chemical Equation Presented) Allyl and propargyl ethers were effectively deallylated or depropargylated to the parent alcohols via a C-O bond cleavage catalyzed by a low-valent titanium reagent (LVT), Ti(O-i-Pr)4/TMSCI/ Mg or Ti(O-i-Pr)4/MgBr2/Mg, under mild reaction conditions. Differentiation between the allyl and propargyl ethers was achieved by the reaction in the presence of AcOEt as an additive. The reagent also catalyzed intra- and intermolecular cyclotrimerization reactions of alkynes to substituted benzenes.
- Ohkubo, Mutsumi,Mochizuki, Sayaka,Sano, Takeshi,Kawaguchi, Yuuki,Okamoto, Sentaro
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p. 773 - 776
(2007/10/03)
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- Silica triflate as a new, mild and efficient catalyst for tetrahydropyranylation of alcohols and deprotection of tetrahydropyranyl ethers
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Silica triflate, a new stable derivative of silica gel, is easily prepared by the reaction of silica gel with trifluoromethanesulfonyl chloride. Silica triflate acts as a highly effective and reusable catalyst for tetrahydropyranylation of alcohols and deprotection of tetrahydropyranyl ethers under mild and completely heterogeneous reaction conditions.
- Shirini,Marjani,Nahzomi, H. Taherpour
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p. 2235 - 2240
(2008/02/08)
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- Discovery of highly potent and selective benzyloxybenzyl-based peroxisome proliferator-activator receptor (PPAR) δ agonists
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A series of 1,4-benzyloxybenzylsulfanylaryl carboxylic acids were prepared and their activities for PPAR receptor subtypes (α, δ, and γ) with potential indications for the treatment of dyslipidemia were investigated. Analog 13a displayed the greatest binding affinity (IC50 = 10 nM) and selectivity (120-fold) for PPARδ over PPARα. Many of the analogs investigated were found to be highly selective for PPARδ and were dependent on the point of attachment of the substituent. In the 1,4-series, analog 28e was found to be the most potent (IC50 = 1.7 nM) and selective (>1000-fold) compound for PPARδ. None of the compounds tested showed appreciable binding affinity for PPARγ.
- Bratton, Larry D.,Filzen, Gary F.,Geyer, Andrew,Hoffman, Jennifer K.,Lu, Gina,Pulaski, Jim,Trivedi, Bharat K.,Unangst, Paul C.,Xu, Xiangyang
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p. 3624 - 3629
(2008/02/13)
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- [Ce(NO3)3]3-H2IO6: Efficient oxidation reactions under solvent-free conditions
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Efficient solvent-free oxidation of alcohols, deprotection and oxidative deprotection of trimethylsilyl ethers and oxidative deprotection of oximes using tris [trinitratocerium (IV)] paraperiodate (TTCPP) is reported.
- Shirini,Esm-Hosseini,Hejazi,Mohammadpoor-Baltork
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- 2-Benzyl and 2-phenyl-3-hydroxypropyl pivalates as protein kinase C ligands
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A series of 2-benzyl and 2-phenyl-3-hydroxypropyl pivalates designed to incorporate the principal pharmacophores of phorbol esters have been synthesized and tested as PKC-α ligands. Among the analogues, 13c exhibited the most potent binding affinity with a Ki = 0.7 μM. The synthesized analogues were subjected to molecular modeling analysis based on two alternative models of the phorbol pharmacophore and a docking study of 13c was carried out.
- Lee, Jeewoo,Lee, Ju-Hyun,Kim, Su Yeon,Perry, Nicholas A.,Lewin, Nancy E.,Ayres, Jolene A.,Blumberg, Peter M.
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p. 2022 - 2031
(2007/10/03)
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- Clean and selective oxidation of aromatic alcohols using silica-supported Jones' reagent in a pressure-driven flow reactor
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By exploiting the high surface to volume ratio obtained within continuous flow reactors, we are able to oxidise selectively an array of primary alcohols to either the aldehyde or carboxylic acid, depending on the flow rates employed, demonstrating a degree of reaction control unattainable in traditional stirred reactors.
- Wiles, Charlotte,Watts, Paul,Haswell, Stephen J.
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p. 5261 - 5264
(2007/10/03)
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- Design, synthesis, and conformational dynamics of a gated molecular basket
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We have developed a synthesis and examined the conformational behavior and recognition properties of dynamic molecular containers 1-3. As follows from the 1H NMR dilution, diffusion NMR, and vapor pressure osmometry measurements, compound 1 has a low affinity for intermolecular aggregation and is mostly present in monomeric form in dilute chloroform solutions. Inspecting the O-H chemical shift resonances of 1, 3, and model compound 4 as a function of temperature afforded the Δδ/ΔT coefficients of 17.0, 17.3, and 4.7 ppb K-1, respectively. In combination with the results from variable temperature 1H NMR and IR measurements, the existence of conformers of 1 and 3 in equilibrium, each having a different extent of hydrogen bonding, was confirmed. Molecular mechanics calculations suggested 1 a as the most favorable conformation, with three additional conformers, 1b, 1C, and 1d, populating local energy minima. Further optimization of each of the four conformers using semiempirical PM3 and ab initio (HF/6-31G*) methods allowed a determination of their relative free energies and the corresponding Boltzmann population distributions which were heavily weighted toward 1a. A computed composite IR spectrum of a fraction-weighted mixture of the conformers of 1 reproduced the experimentally observed IR spectrum in its structural features, leading to a conclusion that conformer 1a indeed dominates the equilibrium. The egg-shaped cavity of 1 (136.6 A3) is complementary in size, shape, and electrostatic potential to chloroform (74.9 A3). A single-crystal X-ray study of 2 revealed a disordered chloroform molecule positioned inside the cavitand along its C3, axis.
- Maslak, Veselin,Yan, Zhiqing,Xia, Shijing,Gallucci, Judith,Hadad, Christopher M.,Badjic, Jovica D.
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p. 5887 - 5894
(2007/10/03)
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- (NO3)3CeBrO3: Solvent-free oxidation of alcohols and deprotection and oxidative deprotection of trimethylsilyl ethers
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Trinitratocerium(IV) bromate (TNCB) can be used as an efficient reagent for oxidation of alcohols and deprotection and oxidative deprotection of trimethylsilyl ethers under solvent-free conditions. Copyright Taylor & Francis, Inc.
- Shirini, Farhad,Esm-Hosseini, Majid,Hejazi, Zoha
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p. 2913 - 2919
(2007/10/03)
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- Total synthesis of (-)-ephedradine A: An efficient construction of optically active dihydrobenzofuran-ring via C-H insertion reaction
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The stereocontrolled total synthesis of (-)-ephedradine A (1) has been accomplished. Construction of optically active dihydrobenzofuran-ring was performed by a novel asymmetric C-H insertion reaction. After an intramolecular ester-amide exchange reaction and a Sharpless asymmetric aminohydroxylation reaction, construction of the complex macrocyclic ring was performed by Ns-strategy and an intramolecular aza-Wittig reaction. Graphical Abstract.
- Kurosawa, Wataru,Kobayashi, Hideki,Kan, Toshiyuki,Fukuyama, Tohru
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p. 9615 - 9628
(2007/10/03)
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- Synthesis of Ether Oligomers
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(Equation presented) Hydroxyaromatic aldehydes and ketones were used as building blocks to prepare ether oligomers. An iterative two-step protocol involving Mitsunobu coupling and carbonyl reduction provided a protecting-group-free route with high yields. Activity screening of an 84-member library against proteases led to the discovery of micromolar inhibitors for trypsin, chymotrypsin, and subtilisin.
- Renaudet, Olivier,Reymond, Jean-Louis
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p. 397 - 400
(2007/10/03)
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