33106-26-2Relevant academic research and scientific papers
6-HETEROARYLOXY BENZIMIDAZOLES AND AZABENZIMIDAZOLES AS JAK2 INHIBITORS
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, (2021/11/13)
The present disclosure provides 6-heteroaryloxy benzimidazole and azabenzimidazole compounds and compositions thereof useful for inhibiting JAK2.
Benzoxaborole Catalyst for Site-Selective Modification of Polyols
Kusano, Shuhei,Miyamoto, Shoto,Matsuoka, Aki,Yamada, Yuji,Ishikawa, Ryuta,Hayashida, Osamu
supporting information, p. 1598 - 1602 (2020/02/11)
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.
Regio/site-selective alkylation of substrates containing a: Cis -, 1,2- or 1,3-diol with ferric chloride and dipivaloylmethane as the catalytic system
Lv, Jian,Liu, Yu,Zhu, Jia-Jia,Zou, Dapeng,Dong, Hai
supporting information, p. 1139 - 1144 (2020/03/11)
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.
C -Methylation of Alcohols, Ketones, and Indoles with Methanol Using Heterogeneous Platinum Catalysts
Siddiki, S. M. A. Hakim,Touchy, Abeda S.,Jamil, Md. A. R.,Toyao, Takashi,Shimizu, Ken-Ichi
, p. 3091 - 3103 (2018/04/14)
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.
Epoxide hydrolysis and alcoholysis reactions over crystalline Mo-V-O oxide
Zhang, Xiaochen,Wang, Min,Zhang, Chaofeng,Lu, Jianmin,Wang, Yehong,Wang, Feng
, p. 70842 - 70847 (2016/08/05)
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.
Regioselective, borinic acid-catalyzed monoacylation, sulfonylation and alkylation of diols and carbohydrates: Expansion of substrate scope and mechanistic studies
Lee, Doris,Williamson, Caitlin L.,Chan, Lina,Taylor, Mark S.
supporting information; experimental part, p. 8260 - 8267 (2012/07/14)
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.
Copper(I)-catalyzed asymmetric desymmetrization: Synthesis of five-membered-ring compounds containing all-carbon quaternary stereocenters
Aikawa, Kohsuke,Okamoto, Tatsuya,Mikami, Koichi
supporting information; experimental part, p. 10329 - 10332 (2012/07/30)
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.
FUSED HETEROCYCLIC COMPOUND
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Page/Page column 314-315, (2010/11/28)
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.
Solvolysis of benzyl alcohols and ethers in 1,2-diols and application to a deprotection of benzyl ether-type protecting groups
Miyake, Hideyoshi,Fujimura, Masahiro,Tsumura, Takatsugu,Sasaki, Mitsuru
, p. 778 - 779 (2007/10/03)
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
Highly enantioselective lipase-catalyzed kinetic resolution of 2-silyloxy-1-propanol
Kawanami, Yasuhiro,Itoh, Kennji
, p. 682 - 683 (2007/10/03)
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
