- Cobalt-Catalyzed Cross-Dehydrogenative Coupling Reactions of (Benz)oxazoles with Ethers
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The cobalt-catalyzed cross-dehydrogenative coupling of (benz)oxazoles and ethers is described. Access to some important bioactive heteroaryl ether derivatives was achieved using CoCO3 as an inexpensive catalyst at levels as low as 1.0 mol %. In
- Li, Yanrong,Wang, Mengshi,Fan, Wei,Qian, Fen,Li, Guigen,Lu, Hongjian
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p. 11743 - 11750
(2016/12/09)
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- Synthesis of oxazoles by silver catalysed oxidative decarboxylation-cyclization of α-oxocarboxylates and isocyanides
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A silver catalysed synthesis of oxazoles by the oxidative decarboxylation-cyclization of α-oxocarboxylates and isocyanides was developed. This method provided a novel strategy to construct oxazole rings compared to traditional methods. Mechanistic investigations such as operando IR, EPR and radical inhibition experiments were carefully done and confirmed the acyl cation and Ag(ii) as the intermediates in this transformation, and the involvement of a radical decarboxylative process.
- Ma, Yiyang,Yan, Zhiyuan,Bian, Changliang,Li, Ke,Zhang, Xiaowen,Wang, Mengfan,Gao, Xinlong,Zhang, Heng,Lei, Aiwen
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supporting information
p. 10524 - 10527
(2015/06/25)
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- Highly diastereo- and enantioselective silver-catalyzed double [3+2] cyclization of α-imino esters with isocyanoacetate
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Presented herein is a new complexity-generating method in which both functionalities of α-imino esters undergo stereoselective cyclization with isocyanoacetates to produce directly linked oxazole-imidazolines, which can be transformed into highly functionalized α,β-diamino esters and imidazolinium salts in high diastereo- and enantiopurity. Double up: An unprecedented silver-catalyzed title reaction has been developed and provides access to directly linked oxazole-imidazolines. A highly diastereo- and enantioselective variant was also realized using the catalyst Ag/L*. The products can be easily transformed into highly functionalized chiral α,β-diamino esters or imidazolinium salts which are useful motifs in asymmetric synthesis and catalysis.
- Shao, Pan-Lin,Liao, Jia-Yu,Ho, Yee Ann,Zhao, Yu
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supporting information
p. 5435 - 5439
(2014/06/09)
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- Nickel-catalyzed decarboxylative acylation of heteroarenes by sp 2 C-H functionalization
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Nickel-catalyzed ligand-free decarboxylative cross-coupling of azole derivatives with α-oxoglyoxylic acids has been developed. This work represents the first example of decarboxylative cross-coupling reactions, in a C-H bond functionalization manner, thro
- Yang, Ke,Zhang, Cheng,Wang, Peng,Zhang, Yan,Ge, Haibo
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supporting information
p. 7241 - 7244
(2014/06/23)
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- Nickel-catalyzed decarboxylative arylation of heteroarenes through sp2 C-H functionalization
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The direct decarboxylative arylation of hetereoarenes with benzoic acids through a nickel-catalyzed sp2 C-H functionalization process was developed. This process provides the first examples of decarboxylative cross-coupling reactions with aroma
- Yang, Ke,Wang, Peng,Zhang, Cheng,Kadi, Adnan A.,Fun, Hoong-Kun,Zhang, Yan,Lu, Hongjian
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supporting information
p. 7586 - 7589
(2015/04/22)
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- OLED driver for the passive matrix display
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An OLED (organic light-emitting diode) passive-matrix display includes a display portion and a driver portion. The display portion includes a matrix of OLEDs for displaying information. The driver portion includes a monitor circuit and a voltage adjusting circuit. The voltage adjusting circuit has a power-up portion that generates a supply voltage based on a reference voltage. In response to an indication to switch modes, the voltage adjusting circuit switches to an operational mode wherein the supply voltage is generated based on the maximum voltage drop read across the OLEDs.
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- PROCESS FOR PRODUCING OPTICALLY ACTIVE β-HYDROXY-α-AMINOCARBOXYLIC ACID DERIVATIVE
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[PROBLEMS] To provide a process for efficiently producing the anti isomer of an optically active β-hydroxy-α-aminocarboxylic acid derivative useful as an intermediate for medicines/agricultural chemicals. [MEANS FOR SOLVING PROBLEMS] The process, which is for producing an optically active β-hydroxy-α-aminocarboxylic acid derivative represented by the formula (2) or (3) [Chemical formula 3] (wherein R1 means (un)substituted C1-20 alkyl or an (un)substituted C4-12 aromatic group and R2 means (un)substituted C1-20 alkyl or an (un)substituted C4-12 aromatic group), comprises hydrogenating an α-aminoacylacetic ester compound represented by the formula (1): [Chemical formula 1] [wherein R1 and R2 have the same meanings as defined above] in the presence of an acid through a catalytic asymmetric hydrogenation reaction employing as a catalyst a rhodium complex having as a ligand an optically active compound represented by the formula (4), (4'), or (5): [Chemical formula 2] the process being characterized in that the hydrogenation is conducted in the presence of an acetic acid salt.
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Page/Page column 23-24
(2008/06/13)
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- PROCESS FOR PRODUCTION OF OPTICALLY ACTIVE BETA-HYDROXY- ALPHA-AMINOCARBOXYLIC ACID DERIVATIVES
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There is provided a process for efficiently producing an anti form of an optically active β-hydroxy-α-aminocarboxylic acid derivative that is useful as an intermediate for pharmaceuticals and agrochemicals. The process for producing optically active β-hydroxy-α-aminocarboxylic acid derivative of formula (2) or (3) wherein R1 is substituted or unsubstituted C1-20 alkyl group, or substituted or unsubstituted C4-12 aromatic group, R2 is substituted or unsubstituted C1-20 alkyl group, or substituted or unsubstituted C4-12 aromatic group, characterized by comprising subjecting an α-aminoacyl acetic acid ester compound of formula (1) wherein R1 and R2 have the same meaning as the above, to hydrogenation by catalytic asymmmetric hydrogenation in the presence of an acid.
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Page/Page column 20-21
(2010/11/08)
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- Nonionic superbase-promoted synthesis of oxazoles and pyrroles: Facile synthesis of porphyrins and α-C-acyl amino acid esters
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The reaction of acyl chlorides or acid anhydrides with isocyanoacetates in the presence of the superior strong nonionic base P(MeNCH2CH2)3N (1) gave oxazoles in 98-99% yield. Treatment of the oxazoles with HCl-MeOH gave α-
- Tang,Verkade
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p. 7793 - 7802
(2007/10/02)
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- CHEMICAL AND STRUCTURAL IMPLICATIONS OF BOND FORMATION BETWEEN THE BRIDGEHEAD ATOMS IN Z-P(MeNCH2CH2)3N SYSTEMS
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A rationale is offered for the stable partially transannulated structures found for the title systems.The unusual basicity of the parent compound (Z = lone pair) is discussed.
- Tang, J.-S.,Laramay, M. A. H.,Verkade, J. G.
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p. 205 - 208
(2007/10/02)
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- NEW METHODS AND REAGENTS IN ORGANIC SYNTHESIS. 22. DIPHENYL PHOSPHORAZIDATE AS A REAGENT FOR C-ACYLATION OF METHYL ISOCYANOACETATE WITH CARBOXYLIC ACIDS
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Diphenyl phosphorazidate(DPPA) can be used efficiently for the direct C-acylation of methyl isocyanoacetate with carboxylic acids, giving 4-methoxycarbonyloxazoles.
- Hamada, Yasumasa,Shioiri, Takayuki
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p. 235 - 236
(2007/10/02)
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