- Carbon monoxide and carbon dioxide insertion chemistry of f-block N-heterocyclic carbene complexes
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The reactions of f-block silylamido N-heterocyclic carbene (NHC) complexes ([M(L)(N{SiMe3}2)2], M = Y, Ce, and U, L = bidentate alkoxy-tethered NHC ligand) with CO and CO2 have been studied and compared to each
- Arnold, Polly L.,Turner, Zoee R.,Germeroth, Anne I.,Casely, Ian J.,Nichol, Gary S.,Bellabarba, Ronan,Tooze, Robert P.
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Read Online
- Trihydroborates and Dihydroboranes Bearing a Pentacoordinated Phosphorus Atom: Double Ring Expansion To Balance the Coordination States
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The first trihydroborate bearing a pentacoordinated phosphorus atom was synthesized as a new P?B bonded compound. Hydride abstraction of the trihydroborate gave an intermediary dihydroborane, which showed hydroboration reactivity and was trapped with pyridine whilst maintaining the P?B bond. The dihydroborane underwent a rearrangement, which involved a double ring expansion to compensate for the unbalanced coordination states of the phosphorus and boron atoms, to give a new fused bicyclic phosphine-boronate.
- Kano, Naokazu,O'Brien, Nathan J.,Uematsu, Ryohei,Ramozzi, Romain,Morokuma, Keiji
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Read Online
- Lewis Acid-Catalyzed Nucleophilic Substitutions of Benzylic Alcohols with Sulfamides
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Nucleophilic substitutions of benzylic alcohols with sulfamides were achieved using an FeCl3 Lewis acid catalyst in MeNO2. It was necessary to adjust the reaction conditions to obtain efficient yields depending on the stability of the carbocation intermediates. The reaction could easily be performed, and it was revealed that a variety of diarylmethanols and benzylic alcohols were applicable to the reaction, irrespective of the type and position of the substituents. The sulfamide moieties were easily deprotected and converted into amine groups.
- Oda, Ryoga,Nakata, Kenya
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p. 295 - 301
(2020/12/11)
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- Implication of a Silyl Cobalt Dihydride Complex as a Useful Catalyst for the Hydrosilylation of Imines
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Here, we describe the formation and use of silyl cobalt (III) dihydride complexes as powerful catalysts for the hydrosilylation of a variety of imines starting from a low-valent well-defined cobalt (I) complex. The reaction is efficient at low catalyst loadings with a diverse range of imines bearing various protecting groups, as well as aliphatic ketimines and quinoline. Kinetics, DFT calculations, NMR spectroscopic studies, deuteration experiments, and X-ray diffraction analyses allowed us to propose a catalytic cycle based on silyl dihydrocobalt (III) complexes performing a hydrocobaltation.
- Barbazanges, Marion,Bories, Cassandre C.,Derat, Etienne,Petit, Marc
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p. 14262 - 14273
(2021/11/27)
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- Electrochemical Oxidative C(sp3)-H/N-H Coupling of Diarylmethanes with Sulfoximines or Benzophenone Imine
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Herein, we report an efficient electrochemical method for the synthesis of N-alkylated sulfoximines by electrochemical oxidative C(sp3)-H/N-H coupling of sulfoximines and diarylmethanes. In addition, we used the same conditions for electrochemical dehydrogenative amination of diarylmethanes with benzophenone imine as an aminating agent. The reactions showed good functional group tolerance and afforded the corresponding products in moderate to good yields without the use of a stoichiometric oxidant, a metal catalyst, or an activating agent.
- Kong, Xianqiang,Tian, Yan,Chen, Xiaohui,Chen, Yiyi,Wang, Wei
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p. 13610 - 13617
(2021/10/01)
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- A convenient Hofmann reaction of carboxamides and cyclic imides mediated by trihaloisocyanuric acids
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A simple, efficient and pot-economic approach in a single vessel has been developed for conversion of aromatic and aliphatic carboxamides into primary amines with one fewer carbom atom (Hofmann reaction) in 38–89 % yield by reacting with trichloro- or tribromoisocyanuric acid and sodium hydroxide in aqueous acetonitrile. Under the same reaction conditions, cyclic imides gave amino acids (69–83 %). The role of the trihaloisocyanuric acids is the in situ generation of N-haloamides, key-intermediates for the Hofmann reaction. The scalability of the methodology was demonstrated by a multigram-scale transformation of phthalimide into anthranilic acid in 77 % yield.
- Bastos, Gustavo A.,de Mattos, Marcio C.S.
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- Effects of ruthenium hydride species on primary amine synthesis by direct amination of alcohols over a heterogeneous Ru catalyst
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Heterogeneously catalysed synthesis of primary amines by direct amination of alcohols with ammonia has long been an elusive goal. In contrast to reported Ru-based catalytic systems, we report that Ru-MgO/TiO2 acts as an effective heterogeneous catalyst for the direct amination of a variety of alcohols to primary amines at low temperatures of ca. 100 °C without the introduction of H2 gas. The present system could be applied to a variety of alcohols and provides an efficient synthetic route for 2,5-bis(aminomethyl)furan (BAMF), an attention-getting biomonomer. The high catalytic performance can be rationalized by the reactivity tuning of Ru-H species using MgO. Spectroscopic measurements suggest that MgO enhances the reactivity of hydride species by electron donation from MgO to Ru.
- Hara, Michikazu,Kamata, Keigo,Kita, Yusuke,Kuwabara, Midori,Yamadera, Satoshi
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p. 9884 - 9890
(2020/10/06)
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- Rh(III)-catalyzed synthesis of isoquinolines using the N-Cl bond of N-chloroimines as an internal oxidant
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The Rh(III)-catalyzed coupling of N-chloroimines with alkynes for the efficient synthesis of isoquinolines is reported. This represents the first use of the N-Cl bond of N-chloroimines as an internal oxidant for construction of the isoquinoline skeleton. The synthesis features atom and step economy, a green solvent (EtOH), mild reaction conditions, and a broad substrate scope.
- Chu, Benfa,Fang, Lili,Guo, Shan,Qi, Bing,Shi, Pengfei,Wang, Qi,Zhu, Jin
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supporting information
(2020/03/10)
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- Hydrogenation reaction method
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The invention relates to a hydrogenation reaction method, and belongs to the technical field of organic synthesis. The hydrogenation reaction method provided by the invention comprises the following steps: carrying out a hydrogen transfer reaction on a hydrogen acceptor compound, pinacol borane and a catalyst in a solvent in the presence of proton hydrogen, so that the hydrogen acceptor compound is subjected to a hydrogenation reaction; the catalyst is one or more than two of a palladium catalyst, an iridium catalyst and a rhodium catalyst; the hydrogen acceptor compound comprises one or morethan two functional groups of carbon-carbon double bonds, carbon-carbon triple bonds, carbon-oxygen double bonds, carbon-nitrogen double bonds, nitrogen-nitrogen double bonds, nitryl, carbon-nitrogentriple bonds and epoxy. The method is mild in reaction condition, easy to operate, high in yield, short in reaction time, wide in substrate application range, suitable for carbon-carbon double bonds,carbon-carbon triple bonds, carbon-oxygen double bonds, carbon-nitrogen double bonds, nitrogen-nitrogen double bonds, nitryl, carbon-nitrogen triple bonds and epoxy functional groups, good in selectivity and high in reaction specificity.
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Paragraph 0034; 0245-0248
(2020/05/14)
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- Generalized Chemoselective Transfer Hydrogenation/Hydrodeuteration
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A generalized, simple and efficient transfer hydrogenation of unsaturated bonds has been developed using HBPin and various proton reagents as hydrogen sources. The substrates, including alkenes, alkynes, aromatic heterocycles, aldehydes, ketones, imines, azo, nitro, epoxy and nitrile compounds, are all applied to this catalytic system. Various groups, which cannot survive under the Pd/C/H2 combination, are tolerated. The activity of the reactants was studied and the trends are as follows: styrene'diphenylmethanimine'benzaldehyde'azobenzene'nitrobenzene'quinoline'acetophenone'benzonitrile. Substrates bearing two or more different unsaturated bonds were also investigated and transfer hydrogenation occurred with excellent chemoselectivity. Nano-palladium catalyst in situ generated from Pd(OAc)2 and HBPin extremely improved the TH efficiency. Furthermore, chemoselective anti-Markovnikov hydrodeuteration of terminal aromatic olefins was achieved using D2O and HBPin via in situ HD generation and discrimination. (Figure presented.).
- Wang, Yong,Cao, Xinyi,Zhao, Leyao,Pi, Chao,Ji, Jingfei,Cui, Xiuling,Wu, Yangjie
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supporting information
p. 4119 - 4129
(2020/08/10)
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- A General Method for Photocatalytic Decarboxylative Hydroxylation of Carboxylic Acids
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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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- Platinum-(phosphinito-phosphinous acid) complexes as bi-talented catalysts for oxidative fragmentation of piperidinols: An entry to primary amines
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Platinum-(phosphinito-phosphinous acid) complex catalyzes the oxidative fragmentation of hindered piperidinols according to a hydrogen transfer induced methodology. This catalyst acts successively as both a hydrogen carrier and soft Lewis acid in a one pot-two steps process. This method can be applied to the synthesis of a wide variety of primary amines in a pure form by a simple acid-base extraction without further purification.
- Membrat, Romain,Vasseur, Alexandre,Moraleda, Delphine,Michaud-Chevallier, Sabine,Martinez, Alexandre,Giordano, Laurent,Nuel, Didier
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p. 37825 - 37829
(2019/12/03)
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- Photochemical C?H Amination of Ethers and Geminal Difunctionalization Reactions in One Pot
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A mild, atom-economic, and metal-free α-C?H amination of ethers using relatively stable nonafluorobutanesulfonyl (nonaflyl, Nf) azide as the aminating reagent to give N-sulfonyl hemiaminals is reported. This enables unprecedented C(sp3) difunctionalization reactions, leading to diverse functionalized amino group containing compounds starting from simple ethers in one pot.
- Hernández-Guerra, Daniel,Hlava?ková, Anna,Pramthaisong, Chiranan,Vespoli, Ilaria,Pohl, Radek,Slanina, Tomá?,Jahn, Ullrich
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p. 12440 - 12445
(2019/08/07)
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- Nano-Fe3O4@SiO2-SO3H: A magnetic, reusable solid-acid catalyst for solvent-free reduction of oximes to amines with the NaBH3CN/ZrCl4 system
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In this study, the immobilization of sulfonic acid on silica-layered magnetite was carried out by the reaction of ClSO3H with silica-layered magnetite. The prepared magnetic nanoparticles of Fe3O4@SiO2-SO3H were then characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometry, and transmission electron microscopy. The sulfonated nanocomposite exhibited excellent catalytic activity and reusability in the reduction of various aldoximes and ketoximes with NaBH3CN in the presence of ZrCl4. All reactions were carried out under solvent-free conditions (r.t. or 75–80°C) within 3–70 min to afford amines in high to excellent yields.
- Sadighnia, Leila,Zeynizadeh, Behzad,Karami, Shiva,Abdollahi, Mohammad
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p. 535 - 542
(2019/01/04)
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- Benzhydrylamine: An effective aminating agent for the synthesis of primary amines
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Aldehydes, ketones, alkyl toluene-p-sulfonates and halides are converted into the corresponding primary amines with benzhydrylamine as a valuable ammonia synthon in moderate to excellent yields.
- Sun, Quan-Wei,Xing, Jun-De,Qin, Yu-Hong,Yin, Xu-Wen,Zhou, Yi
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p. 181 - 183
(2018/05/26)
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- METALLOENZYME INHIBITOR COMPOUNDS
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Provided are compounds having HDAC6 modulating activity, and methods of treating diseases, disorders or symptoms thereof mediated by HDAC6.
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Page/Page column 130
(2018/09/28)
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- Hydrogen bond directed aerobic oxidation of amines via photoredox catalysis
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An application of H-bonding interactions for directing the α-C-H oxidation of amines to amides and amino-ketones catalyzed by an organic photocatalyst is reported. The high efficiency of this method is demonstrated by the aerobic oxidation of pyrrolidines, diarylamines and benzylamines bearing urea groups with high yields and a wide substrate scope.
- Wang, Hongyu,Man, Yunquan,Wang, Kaiye,Wan, Xiuyan,Tong, Lili,Li, Na,Tang, Bo
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supporting information
p. 10989 - 10992
(2018/10/08)
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- Switch in Catalyst State: Single Bifunctional Bi-state Catalyst for Two Different Reactions
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Disclosed here is a molecular switch which responds to acid-base stimuli and serves as a bi-state catalyst for two different reactions. The two states of the switch serve as a highly active and poorly active catalyst for two catalytic reactions (namely a hydrogenation and a dehydrogenative coupling) but in a complementary manner. The system was used in an assisted tandem catalysis set-up involving dehydrogenative coupling of an amine and then hydrogenation of the resulting imine product by switching between the respective states of the catalyst.
- Semwal, Shrivats,Choudhury, Joyanta
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supporting information
p. 5556 - 5560
(2017/05/05)
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- Molecular Coordination-Switch in a New Role: Controlling Highly Selective Catalytic Hydrogenation with Switchability Function
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A molecular coordination-switch controlled by acid-base input has been developed and utilized in switchable catalysis. The molecular switch consists of a hybrid pyridylidene-benzimidazole ligand bound to an IrIIICp? moiety wherein the benzimidazole functionality has been utilized for acid/base controlled reversible coordination, switching between an IrIII-benzimidazole species (form I; neutral imino-type N-coordination) and an IrIII-benzimidazolate species (form II; anionic amido-type N-Ir bonding). Owing to the distinctly different nature of the metal-ligand bonding, it has been demonstrated that while the form I is almost inactive (TOF 1 h-1) in catalytic hydrogenation of imine under ambient pressure and temperature, the form II is greater than an order of magnitude more efficient (TOF 15.8 h-1) in the same catalysis. Moreover, the catalysis could be switched OFF and ON efficiently for several cycles with the addition of acid and base, respectively. Spectroscopic studies and kinetics have been performed to understand the switching activity.
- Semwal, Shrivats,Choudhury, Joyanta
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p. 2424 - 2428
(2016/04/26)
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- One-pot synthesis of primary amines from carboxylic acids through rearrangement of in situ generated hydroxamic acid derivatives
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A one-pot synthesis of primary amines from carboxylic acids through a Lossen rearrangement of hydroxamic acid derivatives, which were in situ generated by the reaction of carboxylic acids with O-trimethylsilylhydroxylamine (NH2OTMS) and carbonyl diimidazole (CDI, 1.5 equiv) in dimethyl sulfoxide at room temperature, has been achieved. This one-pot method could be applied to various carboxylic acids such as aromatic, heteroaromatic, aliphatic, and optically active substrates.
- Hoshino, Yujiro,Ohtsuka, Naoya,Okada, Takuya,Honda, Kiyoshi
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supporting information
p. 5304 - 5307
(2016/11/16)
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- Methanol dehydrogenation by iridium N-heterocyclic carbene complexes
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A series of homogeneous iridium bis(N-heterocyclic carbene) catalysts are active for three transformations involving dehydrogenative methanol activation: acceptorless dehydrogenation, transfer hydrogenation, and amine monoalkylation. The acceptorless dehydrogenation reaction requires base, yielding formate and carbonate, as well as 2-3 equivalents of H2. Of the few homogeneous systems known for this reaction, our catalysts tolerate air and employ simple ligands. Transfer hydrogenation of ketones and imines from methanol is also possible. Finally, N-monomethylation of anilines occurs through a borrowing hydrogen reaction. Notably, this reaction is highly selective for the monomethylated product.
- Campos, Jesús,Sharninghausen, Liam S.,Manas, Michael G.,Crabtree, Robert H.
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p. 5079 - 5084
(2015/06/16)
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- Self-propagated Lossen rearrangement induced by a catalytic amount of activating agents under mild conditions
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A mild self-propagated Lossen rearrangement induced by a catalytic amount of activating agents in medium to high polar organic solvents has been developed. The rearrangement of aromatic and aliphatic hydroxamic acids in the presence of a catalytic amount (0.01 equiv) of acetic anhydride and an equimolar amount of base such as well-dried potassium carbonate afforded the corresponding amines in high yields. This alternative to traditional Lossen rearrangement provides a simple and mild method for the synthesis of amines from free hydroxamic acids.
- Hoshino, Yujiro,Shimbo, Yuki,Ohtsuka, Naoya,Honda, Kiyoshi
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supporting information
p. 710 - 712
(2015/01/30)
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- The efficient solvent-free reduction of oximes to amines with NaBH3CN catalyzed by ZrCl4/nano Fe3O4 system
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Reduction of various aldoximes and ketoximes to the corresponding amines was carried out easily and efficiently with NaBH3CN in the presence of ZrCl4/nano Fe3O4 system. The reactions were carried out under solvent-free conditions at room temperature or 75-80°C to afford amines in high to excellent yields.
- Sadighnia, Leila,Zeynizadeh, Behzad
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p. 873 - 878
(2015/03/18)
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- An unprecedented approach to the Gabriel amine synthesis utilizing tosylhydrazones as alkylating agents
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A new and one-pot version of the Gabriel phthalimide amine synthesis utilizing carbonyl compounds as alkylating agents via their tosylhydrazone surrogates is disclosed. The alkylation involves copper catalysed carbene insertion into the N-H bond of phthalimide. Basically, the protocol also offers a powerful tool for deoxygenative hydroamination of carbonyl compounds.
- Yadav, Arvind K.,Yadav, Lal Dhar S.
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p. 34764 - 34767
(2014/11/08)
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- A novel chimeric amine dehydrogenase shows altered substrate specificity compared to its parent enzymes
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We created a novel chimeric amine dehydrogenase (AmDH) via domain shuffling of two parent AmDHs ('L- and F-AmDH'), which in turn had been generated from leucine and phenylalanine DH, respectively. Unlike the parent proteins, the chimeric AmDH ('cFL-AmDH') catalyzes the amination of acetophenone to (R)-methylbenzylamine and adamantylmethylketone to adamantylethylamine.
- Bommarius, Bettina R.,Schürmann, Martin,Bommarius, Andreas S.
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p. 14953 - 14955
(2015/02/19)
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- Silver nanoparticles supported on alumina-a highly efficient and selective nanocatalyst for imine reduction
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Silver nanoparticles supported on alumina were prepared and tested in the catalytic reduction of various imines to primary and secondary amines and were shown to be exceptionally active and chemoselective. Furthermore, the catalytic activity of the prepared nanocatalyst was also tested in the synthesis of secondary amines from primary amines in a tandem reaction protocol (oxidation-imination-reduction) using air and molecular hydrogen as oxidizing and reducing agents, respectively. The reported synthesis is performed under mild reaction conditions, which complies with the demands of modern organic synthesis. Due to the mild reaction conditions and high conversion as well as high selectivity, we consider that the utilization of silver nanoparticles supported on alumina represents an attractive and environmentally friendly alternative to the current synthesis of N-alkyl amines.
- Poreddy, Raju,Garcia-Suarez, Eduardo J.,Riisager, Anders,Kegnaes, Soren
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supporting information
p. 4255 - 4259
(2014/03/21)
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- Experimental and computational studies of borohydride catalyzed hydrosilylation of a variety of C=O and C=N functionalities including esters, amides and heteroarenes
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Sodium borohydride and a series of related borohydrides catalyze a transition metal-free hydrosilylation of a variety of C=O and C=N functionalities under mild conditions. Importantly, many of these reactions are possible using the cheap and environmentally benign hydrosilane polymethylhydrosiloxane. A mechanism is proposed based on experimental and computational results.
- Manas, Michael G.,Sharninghausen, Liam S.,Balcells, David,Crabtree, Robert H.
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supporting information
p. 1694 - 1700
(2014/05/06)
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- Discovery and optimization of orally active cyclohexane-based prolylcarboxypeptidase (PrCP) inhibitors
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The synthesis, SAR, binding affinities and pharmacokinetic profiles are described for a series of cyclohexane-based prolylcarboxypeptidase (PrCP) inhibitors discovered by high throughput screening. Compounds show high levels of ex vivo target engagement in mouse plasma 20 h post oral dose.
- Debenham, John S.,Graham, Thomas H.,Verras, Andreas,Zhang, Yong,Clements, Matthew J.,Kuethe, Jeffrey T.,Madsen-Duggan, Christina,Liu, Wensheng,Bhatt, Urmi R.,Chen, Dunlu,Chen, Qing,Garcia-Calvo, Margarita,Geissler, Wayne M.,He, Huaibing,Li, Xiaohua,Lisnock, Jeanmarie,Shen, Zhu,Tong, Xinchun,Tung, Elaine C.,Wiltsie, Judyann,Xu, Suoyu,Hale, Jeffrey J.,Pinto, Shirly,Shen, Dong-Ming
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p. 6228 - 6233
(2013/11/19)
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- OLIGONUCLEOTIDE WITH PROTECTED BASE
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The present invention provides a protected nucleotide for elongation, which can be purified efficiently and in a high yield by a liquid-liquid extraction operation, and can achieve an oligonucleotide production method by a phosphoramidite method. It has been found that the above-mentioned problem can be solved by a particular oligonucleotide comprising a protected base and/or particular oligonucleotide protected by a branched chain-containing aromatic group at 3′-position.
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(2013/10/22)
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- Synthesis and reactivity of trifluoromethyl substituted oxaziridines This paper is dedicated to the memory of Professor Ludovico Ronzini for its precious contribution to the organic chemistry teaching
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This article reports a simple and efficient synthesis of methyl(trifluoromethyl)oxaziridines, a new family of organic oxidizing agents. A detailed study on their oxygen transfer capability with respect to styrene, thioanisole and benzyl alcohol as model substrates for the synthesis of epoxides, sulfoxides and aldehydes is described. Moreover, an oxaziridine auto-oxidation at nitrogen and/or N-benzylic carbon is also reported.
- Perrone, Serena,Rosato, Francesca,Salomone, Antonio,Troisi, Luigino
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p. 3878 - 3884
(2013/06/27)
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- Solvent-free amination of secondary benzylic alcohols with N-nucleophiles catalyzed by FeCl3
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A general, simple, and environmentally friendly method for the direct amination of secondary benzyl alcohols with amides or 4-nitroaniline is described. This method has been applied to a variety of substrates, and the reaction proceeded smoothly at room temperature under solvent-free conditions. CbzNH2 was proved to be very useful in the direct preparation of the benzylic amines from corresponding alcohols.
- Yu, Jian-Jun,Wang, Li-Min,Guo, Feng-Lou,Liu, Jin-Qian,Liu, Ying,Jiao, Ning
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p. 1609 - 1616
(2011/06/23)
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- Synthesis and characterization of N-benzhydrylbenzamide
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Interaction of CD40 ligand (CD40L) with CD40 receptor is one of the most immunologically important interactions that involve in the regulation of T cell dependent B cell proliferation, differentiation and antibody production. Therefore, interfering CD40L interaction with CD40 may have important therapeutic applications. Using the three dimensional structure of CD40-CD40L complex, a small CD40L mimetic molecule, N-benzhydrylbenzamide was designed using computational techniques. This N-benzhydrylbenzamide was synthesized using Gabriel synthesis and Scotten-Baumann benzoylation reactions and characterized by FTIR and NMR spectroscopy. The FTIR spectrum of N-benzhydrylbenzamide shows the presence of various functional groups such as amide, aromatic groups and stretching vibrations for benzene derivatives. In addition, the 1H NMR spectrum of N-benzhydrylbenzamide confirmed the presence of amide and phenyl group hydrogens whereas the 13C NMR spectrum shows the presence of aromatic carbons and carbonyl group carbon. As the N-benzhydrylbenzamide structurally mimics CD40L, it can be considered as a candidate molecule for the further development of novel immunotherapeutic agent.
- Vani, Vemula,Muthukumaran, Sivanandham
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p. 2165 - 2168
(2012/03/10)
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- A rapid and practical protocol for solvent-free reduction of oximes to amines with NaBH4/ZrCl4/Al2O3 system
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Solvent-free reduction of various aldoximes and ketoximes to the corresponding amines was performed easily and efficiently with NaBH4 in the presence of ZrCl4 supported on Al2O3. The reactions were carried out rapidly (within 2 min) at room temperature to afford the amines in high to excellent yields.
- Zeynizadeh, Behzad,Kouhkan, Mehri
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experimental part
p. 3448 - 3452
(2012/02/01)
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- A new and convenient method for reduction of oximes to amines with NaBH3CN in the presence of MoCl5/NaHSO4? H2O system
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Various aldoximes and ketoximes were efficiently reduced to their corresponding amines with NaBH3CN in the presence of MoCl 5/NaHSO4?H2O system. Reduction reactions were carried out in refluxing EtOH or DMF within 0.3-3.8 h to afford the amines in high to excellent yields.
- Kouhkan, Mehri,Zeynizadeh, Behzad
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experimental part
p. 3323 - 3326
(2012/02/04)
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- AMINO-HETEROCYCLIC COMPOUNDS
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The invention provides PDE9-inhibiting compounds of Formula (I), and pharmaceutically acceptable salts thereof, wherein R1, R2, R3, A, and n are as defined herein. Pharmaceutical compositions containing the compounds of Formula I, and uses thereof in treating neurodegenerative and cognitive disorders, such as Alzheimer's disease and schizophrenia, are also provided.
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Page/Page column 27-28
(2010/08/07)
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- Microwave-accelerated reductive amination between ketones and ammonium acetate
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A new procedure for reductive amination between ketones and ammonium acetate has been developed to access a variety of primary amines. This protocol takes advantage of microwave heating to significantly accelerate the reaction and offers a convenient and effective method to access some interesting amines. This new procedure compares favorably to previously reported approaches in terms of practicality, efficiency, and functional group compatibility.
- Dong, Li,Aleem, Saadat,Fink, Cynthia A.
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experimental part
p. 5210 - 5212
(2010/11/05)
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- Reductive amination using ammonia borane
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A variety of primary, secondary, and tertiary amines were prepared in 84-95% yields using ammonia borane for the reductive amination of aldehydes and ketones in the presence of titanium isopropoxide.
- Veeraraghavan Ramachandran,Gagare, Pravin D.,Sakavuyi, Kaumba,Clark, Paul
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experimental part
p. 3167 - 3169
(2010/08/05)
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- Transfer hydrogenation of imines with ammonia-borane: A concerted double-hydrogen-transfer reaction
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(Chemical Equation Presented) Direct transfer hydrogenation of imines was observed with ammonia-borane, which proceeded under mild conditions without the help of a catalyst. The results of deuterium kinetic isotope effects, Hammett correlations, and DFT calculations all support a concerted double-hydrogen- transfer mechanism (see scheme).
- Yang, Xianghua,Zhao, Lili,Fox, Thomas,Wang, Zhi-Xiang,Berke, Heinz
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supporting information; experimental part
p. 2058 - 2062
(2010/06/20)
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- Direct synthesis of acyl azides from carboxylic acids using 2-azido-l,3-dimethylimidazolinium chloride
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Acyl azides were directly synthesized from carboxylic acids by the treatment with 2-azido-l,3-dimethylimidazolinium chloride (ADMC, 1) and amine. This procedure resulted in acyl azides in good yields and was applied to the amidation of amino acid derivatives without racemization of the products.
- Kitamura, Mitsuru,Tashiro, Norifumi,Takamoto, Yusuke,Okauchi, Tatsuo
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scheme or table
p. 731 - 733
(2011/01/08)
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- N-Substituted acetamidines and 2-methylimidazole derivatives as selective inhibitors of neuronal nitric oxide synthase
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A series of N-substituted acetamidines and 2-methylimidazole derivatives structurally related to W1400 were synthesized and evaluated as Nitric Oxide Synthase (NOS) inhibitors. Analogs with sterically hindering isopropyl and phenyl substituents on the benzylic carbon connecting the aromatic core of W1400 to the acetamidine nitrogen, showed good inhibitory potency for nNOS (IC 50= 0.2 and 0.3 μM) and selectivity over eNOS (500 and 1166) and to a lesser extent over iNOS (50 and 100). A molecular modeling study allowed to shed light on the effects of the structural modifications on the selectivity of the designed inhibitors toward the different NOS isoforms.
- MacCallini, Cristina,Patruno, Antonia,Lannutti, Fabio,Ammazzalorso, Alessandra,De Filippis, Barbara,Fantacuzzi, Marialuigia,Franceschelli, Sara,Giampietro, Letizia,Masella, Simona,Felaco, Mario,Re, Nazzareno,Amoroso, Rosa
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supporting information; experimental part
p. 6495 - 6499
(2011/02/16)
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- Rapid, one-pot synthesis of α,α-disubstituted primary amines by the addition of Grignard reagents to nitriles under microwave heating conditions
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A series of α,α-disubstituted amines have been prepared in a simple and efficient one-pot procedure by the addition of Grignard reagents to a series of aliphatic, aromatic, and heteroaromatic nitriles. Key to this reported procedure is the unprecedented addition of the Grignard reagent to the nitrile under heating by microwave irradiation which both significantly improves reaction yields and reduces reaction times. In general, the Grignard addition reaction is complete within 5-10 min at 100 °C followed by rapid reduction with sodium borohydride to give the target amines.
- Gregg, Brian T.,Golden, Kathryn C.,Quinn, John F.,Wang, Hong-Jun,Zhang, Wei,Wang, Ruifang,Wekesa, Francis,Tymoshenko, Dmytro O.
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experimental part
p. 3978 - 3981
(2009/10/04)
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- Reductive amine deallyl- and debenzylation with alkali metal in Silica Gel (M-SG)
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Alkali metals in silica gel (the M-SG materials) are effective reagents for reductive deallylation, debenzylation, debenzhydrylation, and detritylation of amines. As such, these reagents provide a convenient alternative to traditional metal ammonia solutions for this class of deprotections.
- Nandi, Partha,Dye, James L.,Jackson, James E.
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supporting information; experimental part
p. 3864 - 3866
(2009/09/28)
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- Aminoimidazoles as potent and selective human β-secretase (BACE1) inhibitors
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The identification of small molecule aminoimidazoles as potent and selective human β-secretase inhibitors is reported. These analogues demonstrate low nannomolar potency for BACE1 in a FRET assay, exhibit comparable activity in a cell-based (ELISA) assay, and show>100x selectivity for the other structurally related aspartyl proteases BACE2, cathepsin D, renin, and pepsin. Our design strategy was supported by molecular modeling studies based on the cocrystal structure of the HTS-hit 3 in the BACE1 active site. These strategies enabled us to integrate pyridine and pyrimidine groups on 3 extending deep into the S3 region of the BACE1 binding pocket and enhancing the ligand's potency. Compound (R)-37 displayed an IC50 value for BACE1 of 20 nM, cellular activity of 90 nM, and > 100-fold selectivity over related aspartyl proteases. Acute oral administration of (R)-37 at 30 mg/kg resulted in a significant 71% reduction of plasma Aβ40 measured at the 6 h time point in a Tg2576 mouse model (p 0.001). 2009 American Chemical Society.
- Malamas, Michael S.,Erdei, Jim,Gunawan, Iwan,Barnes, Keith,Johnson, Matthew,Yu, Hui,Turner, Jim,Yun, Hu,Wagner, Erik,Fan, Kristi,Olland, Andrea,Bard, Jonathan,Robichaud, Albert J.
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experimental part
p. 6314 - 6323
(2010/03/31)
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- Palladium-catalyzed benzylic arylation of N-benzylxanthone imine
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(Chemical Equation Presented) The direct benzylic arylation of N-benzylxanthone imine with aryl chloride proceeds under palladium catalysis, yielding the corresponding coupling product. The product is readily transformed to benzhydrylamine. Taking into consideration that the imine is readily available from benzylic amine, the overall transformation represents a formal cross-coupling reaction of aryl halide with α-aminobenzyl metal.
- Niwa, Takashi,Yorimitsu, Hideki,Oshima, Koichiro
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supporting information; experimental part
p. 4689 - 4691
(2009/05/13)
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- Catalytic behavior of cationic hydridoruthenium(II) complex, [RuH(NH 3)(PMe3)4]+, in H 2-hydrogenation and transfer hydrogenation of imines
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Catalytic hydrogenation under H2 and transfer hydrogenation of imines by secondary alcohols with hydridoruthenium complexes bearing PMe 3 and PPh3 ligands have been examined. A cationic hydridoruthenium complex, cis-[RuH-(NH3)(PMe3) 4]PF6 (2), derived from cis-[RuH2(PMe 3)4] (1) and NH4PF6, showed higher catalytic activity for H2-hydrogenation of N-benzylideneaniline than neutral complexes such as 1 and cis- [RuClH(PMe3)4] (6). The effectiveness of cationic hydridoruthenium species for the catalytic H 2-hydrogenation of benzylideneaniline was also demonstrated by a marked increase in the yield of N-benzylaniline on treatment of 6 with AgPF 6. The cationic complex 2 was applicable to catalytic transfer hydrogenation of imines with secondary alcohols even in the absence of a base. Isotope labeling experiments using deuterated alcohols revealed that the hydrogen atom bound to the α-carbon of the donor alcohol was transferred exclusively to the imine carbon and alcoholic OD was transferred to the imine nitrogen. A rapid exchange between the alcoholic proton and the hydrido ligand of 2 was also confirmed by NMR investigation using (CH3) 2CHOD. On the basis of the experimental results the mechanisms of the H2-hydrogenation and transfer hydrogenation are discussed.
- Kayaki, Yoshihito,Ikeda, Hibiki,Tsurumaki, Jun-Ichirou,Shimizu, Isao,Yamamoto, Akio
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experimental part
p. 1053 - 1061
(2009/05/06)
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- Photosensitized electron transfer oxidation of sulfides: A steady-state study
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The photosensitized electron-transfer oxidation of a series of ethyl sulfides RSEt (1, R = C12H25; 2, PhCH2CH 2; 3, PhCH2; 4, PhCMe2; 5, Ph2CH) has been examined in acetonitrile and the product distribution discussed on the basis of the mechanisms proposed. In nitrogen-flushed solutions, cleaved alcohols and alkenes are formed, whereas under oxygen, in reactions that are 10-70 times faster, sulfoxides and cleaved aldehydes and ketones are formed in addition to the afore-mentioned products. Two sensitizers are compared, 9,10-dicyanoanthracene (DCA) and 2,4,6-triphenylpyrylium tetrafluoroborate (TPP+BF4-), the former giving a higher proportion of the sulfoxide, the latter of cleaved carbonyls. The sulfoxidation is due to the contribution of the singlet oxygen path with DCA. Oxidative cleavage, on the other hand, occurs both with DCA and with TPP+ which is known to produce neither singlet oxygen nor the superoxide anion. This process involves deprotonation from the α position of the sulfide radical cation, but the TPP+ results suggest that O2.- is not necessarily involved and non-activated oxygen forms a weak adduct with the radical cation promoting α-hydrogen transfer, particularly with benzylic derivatives. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Bonesi, Sergio M.,Fagnoni, Maurizio,Albini, Angelo
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scheme or table
p. 2612 - 2620
(2009/04/05)
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- METHODS OF PREPARING PRIMARY, SECONDARY AND TERTIARY CARBINAMINE COMPOUNDS IN THE PRESENCE OF AMMONIA
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The present application relates to novel methods for the preparation of primary, secondary and tertiary carbinamine compounds, particularly the preparation of compounds of formulae I, IV and VI, from a carbonyl compound of formula II in the presence of ammonia or an ammonium equivalent of the formula NH4+X-, by way of allylation, crotylation, arylation, reductive amination and catalytic hydrogenation.
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Page/Page column 47-48
(2008/12/04)
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- α-Methylation at benzylic fragment of N-aryl-N′-benzyl ureas provides TRPV1 antagonists with better pharmacokinetic properties and higher efficacy in inflammatory pain model
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SAR studies for N-aryl-N′-benzyl urea class of TRPV1 antagonists have been extended to cover α-benzyl alkylation. Alkylated compounds showed weaker in vitro potencies in blocking capsaicin activation of TRPV1 receptor, but possessed improved pharmacokinetic properties. Further structural manipulations that included replacement of isoquinoline core with indazole and isolation of single enantiomer led to TRPV1 antagonists like (R)-16a with superior pharmacokinetic properties and greater potency in animal model of inflammatory pain.
- Gomtsyan, Arthur,Bayburt, Erol K.,Keddy, Ryan,Turner, Sean C.,Jinkerson, Tammie K.,Didomenico, Stanley,Perner, Richard J.,Koenig, John R.,Drizin, Irene,McDonald, Heath A.,Surowy, Carol S.,Honore, Prisca,Mikusa, Joe,Marsh, Kennan C.,Wetter, Jill M.,Faltynek, Connie R.,Lee, Chih-Hung
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p. 3894 - 3899
(2008/02/09)
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- Lewis acid-catalyzed direct amination of benzhydryl alcohols
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The Lewis acid-mediated direct amination of benzylic alcohols is described, providing various benzylic amine derivatives in good yields under mild and environmentally benign conditions. Among the different Lewis acids tested, gold(III) proved to be the catalyst of choice for both chemical (yield, conversion) and practical reasons (a filtration over a silica pad is generally sufficient to obtain the corresponding benzylic amine in analytically pure form).
- Terrasson, Vincent,Marque, Sylvain,Georgy, Marie,Campagne, Jean-Marc,Prim, Damien
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p. 2063 - 2067
(2007/10/03)
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- Synthesis of homo- and heterobiarylmethylamines
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A variety of homo- and heterobiarylmethylamines were prepared in modest to high yields via a convenient one-pot process. Georg Thieme Verlag Stuttgart.
- Terrasson, Vincent,Marque, Sylvain,Scarpacci, Annabelle,Prim, Damien
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p. 1858 - 1862
(2008/01/27)
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