- 6-HETEROARYLOXY BENZIMIDAZOLES AND AZABENZIMIDAZOLES AS JAK2 INHIBITORS
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The present disclosure provides 6-heteroaryloxy benzimidazole and azabenzimidazole compounds and compositions thereof useful for inhibiting JAK2.
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Paragraph 0954; 0956
(2021/11/13)
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- Benzoxaborole Catalyst for Site-Selective Modification of Polyols
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The site-selective modification of polyols bearing several hydroxyl groups without the use of protecting groups remains a significant challenge in synthetic chemistry. To address this problem, novel benzoxaborole derivatives were designed as efficient catalysts for the highly site-selective and protecting-group-free modification of polyols. To identify the effective substituent groups enhancing the catalytic activity and selectivity, a series of benzoxaborole catalysts 1a–k were synthesized. In-depth analysis for the substituent effect revealed that 1i–k, bearing multiple electron-withdrawing fluoro- and trifluoromethyl groups, exhibited the greatest catalytic activity and selectivity. Moreover, 1i-catalyzed benzoylation, tosylation, benzylation, and glycosylation of various cis-1,2-diol derivatives proceeded with good yield and site-selective manner.
- Kusano, Shuhei,Miyamoto, Shoto,Matsuoka, Aki,Yamada, Yuji,Ishikawa, Ryuta,Hayashida, Osamu
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supporting information
p. 1598 - 1602
(2020/02/11)
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- Regio/site-selective alkylation of substrates containing a: Cis -, 1,2- or 1,3-diol with ferric chloride and dipivaloylmethane as the catalytic system
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In this study, we reported the regio/site-selective alkylation of substrates containing a cis-, 1,2- or 1,3-diol with FeCl3 as a key catalyst. A catalytic system consisting of FeCl3 (0.01-0.1 equiv.) and dipivaloylmethane (FeCl3/dipivaloylmethane = 1/2) was used to catalyze the alkylation in the presence of a base. The produced selectivities and isolated yields were similar to those obtained by methods using the same amount of FeL3 (L = acylacetone ligand) as the catalyst in most cases. The previously reported FeL3 catalysts for alkylation are not commercially available and have to be synthesized prior to use. In contrast, FeCl3 and dipivaloylmethane (Hdipm) are very common and inexpensive nontoxic reagents in the lab, thereby making the method much greener and easier to handle. Mechanism studies confirmed for the first time that FeCl3 initially reacts with two equivalents of Hdipm to form [Fe(dipm)3] in the presence of a base in acetonitrile, followed by the formation of a five or six-membered ring intermediate between [Fe(dipm)3] and two hydroxyl groups of the substrate. A subsequent reaction between the cyclic intermediate and the alkylating agent results in selective alkylation of the substrate.
- Lv, Jian,Liu, Yu,Zhu, Jia-Jia,Zou, Dapeng,Dong, Hai
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supporting information
p. 1139 - 1144
(2020/03/11)
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- C -Methylation of Alcohols, Ketones, and Indoles with Methanol Using Heterogeneous Platinum Catalysts
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A versatile, selective, and recyclable heterogeneous catalytic method for the methylation of C-H bonds in alcohols, ketones, and indoles with methanol under oxidant-free conditions using a Pt-loaded carbon (Pt/C) catalyst in the presence of NaOH is reported. This catalytic system is effective for various methylation reactions: (1) the β-methylation of primary alcohols, including aryl, aliphatic, and heterocyclic alcohols, (2) the α-methylation of ketones, and (3) the selective C3-methylation of indoles. The reactions are driven by a borrowing-hydrogen mechanism. The reaction begins with the dehydrogenation of the alcohol(s) to afford aldehydes, which subsequently undergo a condensation reaction with the nucleophile (aldehyde, ketone, or indole), followed by hydrogenation of the condensation product by Pt-H species to yield the desired product. In all of the methylation reactions explored in this study, the Pt/C catalyst exhibits a significantly higher turnover number than other previously reported homogeneous catalytic systems. Moreover, it is demonstrated that the high catalytic activity of Pt can be rationalized in terms of the adsorption energy of hydrogen on the metal surface, as revealed by density functional theory calculations on different metal surfaces.
- Siddiki, S. M. A. Hakim,Touchy, Abeda S.,Jamil, Md. A. R.,Toyao, Takashi,Shimizu, Ken-Ichi
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p. 3091 - 3103
(2018/04/14)
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- Epoxide hydrolysis and alcoholysis reactions over crystalline Mo-V-O oxide
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Crystalline Mo-V-O oxides have been used as a catalyst for the hydrolysis and alcoholysis of propylene oxide to diols and ethers, respectively. Relationships between the active crystal facet, the acidity of Mo-V-O catalysts and the activity have been established. Our results indicate that the a-b plane is the active facet for the hydrolysis reaction.
- Zhang, Xiaochen,Wang, Min,Zhang, Chaofeng,Lu, Jianmin,Wang, Yehong,Wang, Feng
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p. 70842 - 70847
(2016/08/05)
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- Regioselective, borinic acid-catalyzed monoacylation, sulfonylation and alkylation of diols and carbohydrates: Expansion of substrate scope and mechanistic studies
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Synthetic and mechanistic aspects of the diarylborinic acid-catalyzed regioselective monofunctionalization of 1,2- and 1,3-diols are presented. Diarylborinic acid catalysis is shown to be an efficient and general method for monotosylation of pyranoside derivatives bearing three secondary hydroxyl groups (7 examples, 88% average yield). In addition, the scope of the selective acylation, sulfonylation, and alkylation is extended to 1,2- and 1,3-diols not derived from carbohydrates (28 examples); the efficiency, generality, and operational simplicity of this method are competitive with those of state-of-the-art protocols including the broadly applied organotin-catalyzed or -mediated reactions. Mechanistic details of the organoboron-catalyzed processes are explored using competition experiments, kinetics, and catalyst structure-activity relationships. These experiments are consistent with a mechanism in which a tetracoordinate borinate complex reacts with the electrophilic species in the turnover-limiting step of the catalytic cycle.
- Lee, Doris,Williamson, Caitlin L.,Chan, Lina,Taylor, Mark S.
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supporting information; experimental part
p. 8260 - 8267
(2012/07/14)
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- Copper(I)-catalyzed asymmetric desymmetrization: Synthesis of five-membered-ring compounds containing all-carbon quaternary stereocenters
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A highly stereoselective catalytic alkylation sequence for the synthesis of highly functionalized and versatile five-membered-ring compounds bearing all-carbon quaternary stereocenters was developed. Enantioselective desymmetrization of achiral cyclopentene-1,3-diones was thus executed by chiral Cu-phosphoramidite catalysts. A variety of complicated cyclopentane derivatives can be synthesized with excellent stereoselectivities using a low catalyst loading in a one-pot operation.
- Aikawa, Kohsuke,Okamoto, Tatsuya,Mikami, Koichi
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supporting information; experimental part
p. 10329 - 10332
(2012/07/30)
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- FUSED HETEROCYCLIC COMPOUND
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A compound of the formula: wherein ring'' A is a 7-membered or 8-membered nitrogen- containing ring optionally further substituted, ring B is an optionally substituted aryl group or an optionally substituted heteroaryl group, X1 is a group represented by -NR3-Y1-, -0-, -S-, -SO-, -SO2- or -CHR3- wherein R3 is a hydrogen atom or'' an optionally substituted aliphatic hydrocarbon group, or R3 may be bonded to the carbon atom of ring B to form an optionally substituted ring structure, and Y1 is a bond or an optionally substituted C1-4 alkylene, R1 is a hydrogen atom, or an optionally substituted group bonded via a carbon atom or a sulfur atom, the formula = shows a single bond or a double bond, when ===R2 is - R2, R2 is a hydrogen atom, or an optionally substituted group bonded via a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, and when ===R2 is =R2, R2 is an oxo group, an optionally substituted alkylidene group, or an optionally, substituted imino group.
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Page/Page column 314-315
(2010/11/28)
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- Solvolysis of benzyl alcohols and ethers in 1,2-diols and application to a deprotection of benzyl ether-type protecting groups
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Some kinds of benzyl alcohols and ethers react with 1,2-diols, such as ethylene glycol and propylene glycol, at 130-190°C to give 2-hydroxyethyl or 2-hydroxypropyl ethers. Application of this reaction to a deprotection of benzyl ether-type protecting groups, under neutral conditions, was also described. Copyright
- Miyake, Hideyoshi,Fujimura, Masahiro,Tsumura, Takatsugu,Sasaki, Mitsuru
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p. 778 - 779
(2007/10/03)
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- Highly enantioselective lipase-catalyzed kinetic resolution of 2-silyloxy-1-propanol
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The lipase-catalyzed kinetic resolutions of 2-benzyloxy- and 2-silyloxy-1-propanols have been investigated. Efficient modification of the substrate structure with the dimethylphenylsilyl protecting group and the use of lipase PS-D immobilized on diatomace
- Kawanami, Yasuhiro,Itoh, Kennji
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p. 682 - 683
(2007/10/03)
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- Electron-transfer reduction of selected alcohols with alkalide K-, K+(15-crown-5)2 via organometallic intermediates
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The course of the reaction of alkalide K-, K+ (15-crown-5)2 1 with selected alcohols depends on the kind of alcohol and the mode of substrate delivery. In the case of methanol, potassium methoxide formed initially undergoes destructfion at the excess of 1. It results in potassium oxide and methylpotassium. The latter opens the crown ether ring giving potassium tetraethylene glycoxide vinyl ether and methane. A similar course of the process is observed for propanol. Potassium glycidoxide is the main product formed in the reaction of 1 with glycidol. Its oxirane ring is opened at the excess of 1. Organopotassium alkoxides, i.e., potassium potassiomethoxide and dipotassium potassiopropane-1,2-dioxide are intermediate products of this reaction. They react then with the crown ether. Potassium methoxide, potassium enolate of acetaldehyde, dipotassium propane-1, 2-dioxide and potassium tetraethylene glycoxide vinyl ether are the final products of this process.
- Grobelny, Zbigniew,Stolarzewicz, Andrzej,Maercker, Adalbert,Krompiec, Stanis,Kasperczyk, Janusz,Rzepa, Józef,Frey, Holger
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p. 2361 - 2367
(2007/10/03)
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- 2-Alkynyl-and 2-alkenyl-pyrazolo-[4,3-e]-1,2,4-triazolo-[1,5-c]-pyrimidine adenosine A2a receptor antagonists
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Compounds having the structural formula I or a pharmaceutically acceptable salt thereof, wherein R is R1, R2, R3, R4 and R5 are H, alkyl or alkoxyalkyl; R6 is H, alkyl, hydroxyalkyl or —CH2F; R7, R8 and R9 are H, alkyl, alkoxy, alkylthio, alkoxyalkyl, halo or —CF3; and Z is optionally substituted aryl, heteroaryl or heteroaryl-alkyl are disclosed. Also disclosed is the use of compounds of formula I in the treatment of central nervous system diseases, in particular Parkinson's disease, alone or in combination with other agents for treating Parkinson's disease, and pharmaceutical compositions comprising them.
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- Almond oxynitrilase-catalyzed transformation of aldehydes is strongly influenced by naphthyl and alkoxy substituents
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Different α- and β-substituted aldehydes have been submitted to the catalytic action of almond oxynitrilase (PaHNL), in order to explore the influence of a stereocenter already present in the substrate on the selectivity of this enzyme. The results indicate that naphthyl and alkoxy substituents in the α- and also in the β-position to the aldehyde group significantly influence the stereochemical outcome of the PaHNL-catalyzed transformation.
- Roda, Gabriella,Riva, Sergio,Danieli, Bruno
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p. 3939 - 3949
(2007/10/03)
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- Highly selective Silver(I) oxide mediated monoprotection of symmetrical diols
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Treatment of symmetrical diol with Ag2O and alkyl halide gave the monoprotected derivative in good to excellent yield.
- Bouzide, Abderrahim,Sauve, Gilles
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p. 5945 - 5948
(2007/10/03)
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- Aminodiol HIV protease inhibitors. Synthesis and structure - Activity relationships of P1/P1′ compounds: Correlation between lipophilicity and cytotoxicity
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A series of novel aminodiol inhibitors of HIV protease based on the lead compound 1 with structural modifications at P1′ were synthesized in order to reduce the cytotoxicity of 1. We have observed a high degree of correlation between the lipophilicity and the cytotoxicity of this series of inhibitors. It was found that appropriate substitution at the para position of the P1′ phenyl group of 1 resulted in the identification of equipotent (both against the enzyme and in cell culture) compounds (101, 10m, 10n, and 15c) which possess significantly decreased cytotoxicity.
- Chen, Ping,Cheng, Peter T. W.,Alam, Masud,Beyer, Barbara D.,Bisacchi, Gregory S.,Dejneka, Tamara,Evans, Adelaide J.,Greytok, Jill A.,Hermsmeier, Mark A.,Humphreys, W. Griffith,Jacobs, Glenn A.,Kocy, Octavian,Lin, Pin-Fang,Lis, Karen A.,Marella, Michael A.,Ryono, Denis E.,Sheaffer, Amy K.,Spergel, Steven H.,Sun, Chong-Qing,Tino, Joseph A.,Vite, Gregory,Colonno, Richard J.,Zahler, Robert,Barrish, Joel C.
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p. 1991 - 2007
(2007/10/03)
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- Stereoselective Radical Additions of γ-Oxy-α,β-unsaturated Ester Derivatives; 1,2-Asymmetric Induction in Acyclic and Cyclisation Systems
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Examination was made of 1,2-asymmetric induction in the addition of alkyl radicals to γ-oxy-α,β-unsaturated ester derivatives 1 and 2 prepared from ethyl lactate and (R)-2,3-O-isopropylideneglyceraldehyde 3, respectively.The addition reactions of hexyl, cyclohexyl and 3-phenylpropyl radicals to (Z)-2 derived from aldehyde 3 gave β-addition products with syn-stereoselectivity (syn:anti = 8.6:1 - syn only).The reactions of (E)-2 were non-stereoselective.Based on allylic strain, a transition-state model for the syn-stereoselectivity is proposed. 1,2-Asymmetric induction was carried out in radical cyclisation to synthesize optically active cyclohexane derivatives.
- Morikawa, Tsutomu,Washio, Yoshiaki,Harada, Susumu,Hanai, Ryo,Kayashita, Takashi,et al.
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p. 271 - 282
(2007/10/02)
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- REDUCTION OF ACETALS WITH CpTiCl3-LiAlH4
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The reduction of cyclic acetals and ketals derived from aromatic or aliphatic aldehydes and ketones with CpTiCl3-LiAlH4 system in diethyl ether at 30 deg C affords the corresponding hydroxyethyl ethers and the corresponding alkyl benzene or aliphatic hydrocarbons.
- Shaozu, Wu,Yin, Chen,Yulan, Zhang
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p. 421 - 424
(2007/10/02)
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- A efficient method for the reductive cleavage of aromatic acetals with ZrCl4-LiAlH4
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In our survey of the chemistry of ZrCl4-LiAlH4, we have found that acetals can be reduced to the corresponding ethers.We have explored the reductive condition and studied the reductive cleavage of different-membered cyclic acetals
- Shaozu, Wu,Yulan, Zhang,Tianhui, Ren
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p. 445 - 447
(2007/10/02)
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- MICROBIAL REDUCTION OF 2-PHENYLPROPIONIC ACID, 2-BENZYLOXYPROPIONIC ACID AND 2-(2-FURFURYL)PROPIONIC ACID
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Racemic 2-phenylpropionic acid and 2-benzyloxypropionic acid were subjected to microbial reduction and simultaneous resolution with several molds. i. e., Malus and Prunus strains of Glomerella cingulata, Gloeosporium olivarum and Gloeosporium laeticolor, yielding (R)-2-phenylpropanol and (S)-2-benzyloxypropanol , and leaving (R)-2-phenylpropionic acid , respectively.The microbial reduction of racemic 2-(2-furfuryl)propionic acid gave optically inactive (+/-)-2-(2-furfuryl)propanol .Keywords- asymetric reduction; 2-benzyloxypropionic acid; 2-(2-furfuryl)prioionic acid; microbial reduction; microbial resolution; 2-phenylpropionic acid
- Tsuda, Yoshiko,Kawai, Ken-Ichi,Nakajima, Shoichi
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p. 4657 - 4661
(2007/10/02)
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- A FACILE CLEAVAGE OF BENZYLIDENE ACETALS WITH DIISOBUTYLALUMINUM HYDRIDE
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Benzylidene acetals of 1,2- and 1,3-glycols are easily cleft by diisobutylaluminum hydride in a toluene solution at 0 deg C - room temperature to give the corresponding monobenzyl ethers of the glycols.In general the reaction proceeds excellently in regioselective manner depending on the stereochemical environment.
- Takano, Seiichi,Akiyama, Masashi,Sato, Seiji,Ogasawara, Kunio
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p. 1593 - 1596
(2007/10/02)
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- A REASSESSMENT OF THE PHYTOTOXIN, RHYNCHOSPOROSIDE: ATTACHMENT OF THE AGLYCON
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The aglycon of rhynochosporoside has been established as 1,2-propanediol, and its site of attachment has been reassigned from O-2 to O-1 of the aglycon.Syntheses of the corresponding cellobiosides, previously suggested to be the phytotoxic compounds, are
- Beier, Ross C.,Mundy, Bradford P.,Strobel, Gary A.
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