- A novel and efficient synthesis of maleic anhydrides by palladium-catalyzed dicarbonylation of terminal acetylenes in H2O/dioxane
-
Maleic anhydrides can be obtained in high yields by the PdCl2-catalyzed dicarbonylation of terminal acetylenes in H2O/dioxane. It is not necessary to add reoxidants to the reaction, but reoxidants can affect the yield and the rate. We also found that the rate decreased and only traces of maleic anhydrides were formed in the presence of KCl or LiCl.
- Li, Jinheng,Li, Guoping,Jiang, Huanfeng,Chen, Mingcai
-
-
Read Online
- Palladium-catalysed formation of maleic anhydrides from CO, CO2 and alk-1-ynes
-
Carbon dioxide causes palladium-catalysed synthesis of unsaturated γ-lactones from alk-1-ynes and CO to shift towards maleic anhydrides.
- Gabriele, Bartolo,Salerno, Giuseppe,Costa, Mirco,Chiusoli, Gian Paolo
-
-
Read Online
- Palladium-catalyzed dicarbonylation of terminal acetylenes: A new method for selective synthesis of unsaturated diesters and maleic anhydrides
-
Maleate diesters and maleic anhydrides can be synthesized respectively by using different type of alcohol in the palladium-catalyzed dicarbonylation of terminal acetylene. In primary or second aliphatic alcohols, only α,β-unsaturated diesters were yielded. In tert-BuOH, maleic anhydrides were selectively synthesized.
- Li,Jiang,Chen
-
-
Read Online
- Asymmetric hydrogenation of maleic anhydrides catalyzed by Rh/bisphosphine-thiourea: efficient construction of chiral succinic anhydrides
-
Asymmetric hydrogenation of various 3-substituted maleic anhydrides catalyzed by Rh/bisphosphine-thiourea (ZhaoPhos) under mild conditions was successfully developed. A wide range of 3-alkyl and 3-aryl maleic anhydrides were hydrogenated well to provide the desired products 3-substituted succinic anhydrides in one hour with excellent results (full conversions, up to 99% yield, 99% ee, 3000 TON). Importantly, we developed a creative and efficient synthetic route to construct the key intermediate of the hypoglycemic drug mitiglinide through our catalytic system.
- Han, Zhengyu,Wang, Rui,Gu, Guoxian,Dong, Xiu-Qin,Zhang, Xumu
-
p. 4226 - 4229
(2017/04/21)
-
- A dinuclear iron(II) complex bearing multidentate pyridinyl ligand: Synthesis, characterization and its catalysis on the hydroxylation of aromatic compounds
-
A dinuclear iron(II) complex Fe2L2(μ2-Cl)2Cl2 (L = N,N-bis(pyridin-2-ylmethyl)prop-2-yn-1-amine) was prepared and fully characterized by UV–Vis spectroscopy, elemental analysis, electrochemical analysis and X-ray single crystal diffraction analysis. The catalytic activity of the complex was assessed for the hydroxylation of aromatic compounds by using aqueous H2O2 as an oxidant in acetonitrile. The catalytic system was applicable in a wide range of substrates including aromatic compounds with both electron-donating and electron-withdrawing substituents and showed moderate to good catalytic activity and selectivity in the oxidation reactions. Particularly, in the case of benzene the selectivity of phenol achieve to 74% with the reaction conversion of 24.8%.
- Gu, Erxing,Zhong, Wei,Ma, Hongxia,Xu, Beibei,Wang, Hailong,Liu, Xiaoming
-
p. 159 - 165
(2018/03/29)
-
- Discovery of pyrrolopyridazines as novel DGAT1 inhibitors
-
A new structural class of DGAT1 inhibitors was discovered and the structure-activity relationship was explored. The pyrrolotriazine core of the original lead molecule was changed to a pyrrolopyridazine core providing an increase in potency. Further exploration resulted in optimization of the propyl group at C7 and the discovery that the ester at C6 could be replaced by five-membered heterocyclic rings. The analogs prepared have DGAT1 IC 50 values ranging from >10 μM to 48 nM.
- Fox, Brian M.,Iio, Kiyosei,Li, Kexue,Choi, Rebeka,Inaba, Takashi,Jackson, Simon,Sagawa, Shoichi,Shan, Bei,Tanaka, Masahiro,Yoshida, Atsuhito,Kayser, Frank
-
scheme or table
p. 6030 - 6033
(2010/11/05)
-
- Efficient electrochemical dicarboxylations of arylacetylenes with carbon dioxide using nickel as the cathode
-
The electrochemical dicarboxylation of arylacetylenes with carbon dioxide could be smoothly achieved in an undivided cell using Ni as the cathode and Al as the anode with n-Bu4NBr-DMF as the supporting electrolyte, at a constant current under CO2 pressure of 3 MPa and room temperature in the absence of additional catalysts. The corresponding aryl-maleic anhydrides and 2-arylsuccinic acids were afforded in excellent total yields (82-94%). Under anhydrous conditions, an unsaturated aryl-maleic anhydride as the main product was obtained, while the presence of H2O would lead to the formation of saturated 2-arylsuccinic acids. The results of cyclic voltammetric experiments show that a nickel cathode itself plays the catalytic role in the reduction reaction of arylacetylenes with CO2.
- Yuan, Gao-Qing,Jiang, Huan-Feng,Lin, Chang
-
p. 5866 - 5872
(2008/09/21)
-
- A simple, convenient method for the synthesis of maleic anhydrides from α-keto esters and alkanoic acid anhydrides using the TiCl 4/n-Bu3N reagent system
-
Reaction of α-keto esters with alkanoic acid anhydrides using the TiCl4/n-Bu3N reagent system gives the corresponding maleic anhydrides in 62-95% yields.
- Kishorebabu, Neela,Periasamy, Mariappan
-
p. 2107 - 2109
(2007/10/03)
-
- Synthesis of maleic anhydrides and maleic acids by Pd-catalyzed oxidative dicarbonylation of alk-1-ynes
-
We have found that carbon dioxide effectively promotes the Pd-catalyzed oxidative carbonylation of terminal alkynes to give maleic anhydrides in fair yields. Reactions were carried out in aqueous dioxane at 60-80 °C in the presence of catalytic amounts of PdI2 in conjunction with KI and under a 4:1:10 mixture of CO/air/CO2 (60 atm total pressure at 25 °C). By working in the presence of a large excess of water, maleic acids were formed selectively with unprecedented catalytic efficiencies for this kind of reaction. In the latter case, the use of an excess of carbon dioxide tended to inhibit, rather than promote, the reaction. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Gabriele, Bartolo,Veltri, Lucia,Salerno, Giuseppe,Costa, Mirco,Chiusoli, Gian Paolo
-
p. 1722 - 1728
(2007/10/03)
-
- Conversion of alkynes to cyclic imides and anhydrides using reactive iron carbonyls prepared from Fe(CO)5 and Fe3(CO)12
-
Alkyne-iron carbonyl complexes, prepared using Fe(CO)5-NaBH4-CH3COOH-amine-alkyne and Fe3(CO)12-amine-alkyne reagent systems, react with excess of amine at 25 °C to give cyclic imides in moderate to g
- Periasamy, Mariappan,Rameshkumar, Chellappan,Mukkanti, Amere
-
p. 209 - 213
(2007/10/03)
-
- Carbonylation of terminal alkynes using a multicatalytic system, Pd(II)/chlorohydroquinone/NPMoV, under carbon monoxide and dioxygen
-
Carbonylation of terminal alkynes was performed using a new triple catalytic system, Pd(II)/chlorohydroquinone/NPMoV, under carbon monoxide and oxygen. For instance, phenylacetylene was converted into methyl phenylpropiolate (85%) in methanol and phenylmaleic anhydride (62%) in dioxane. The reaction did not take place in the absence of oxygen.
- Sakurai, Yasunori,Sakaguchi, Satoshi,Ishii, Yasutaka
-
p. 1701 - 1704
(2007/10/03)
-
- Furan-2(3H)- and -2(5H)-ones. Part 6. Di-?-methane rearrangement of the α-substituted 4-benzylfuran-2(5H)-one system
-
The effect of the 'central methane' substitution on the di-?-methane rearrangement in 4-benzyl-2,5-dihydrofuran-2-ones 8a-d was investigated.Significant enhancement of efficiency in the rearrangement leading in high combined yields to two isomeric products, endo-12 and exo-12, is discussed in terms of both the substituent effects at the benzylic carbon and the restrained features of the ring-enrolled ?-system.The origin of the difference in chemoselectivity compared with that of the 3-benzyl counterpart 5 where a photoarylated product 6 resulted upon photoirradiation was also investigated, and was rationalized by postulating a higher reactivity at the β-position of the enone system.
- Muraoka, Osamu,Tanabe, Genzoh,Higachiura, Mie,Minematsu, Toshie,Momose, Takefumi
-
p. 1437 - 1444
(2007/10/02)
-
- Facile synthesis of arylmaleic acids and anhydrides
-
A process for making acrylmaleic acid and arylmaleic anhydride derivative useful as intermediates for the preparation of arylmaleimides in the synthesis of compounds having activity in the central nervous system. The process involves reacting arylacetonitriles with glyoxylic acid to provide novel intermediate 3-aryl-3-cyanopropeneoates which may be converted to the arylmaleic acid and arylmaleic anhydride derivatives.
- -
-
-
- Arylation of olefins
-
An olefin, especially an activated olefin, is arylated by reaction with an arylamine, such as an aniline, in an inert polar organic solvent and in the presence of an alkyl nitrite, a hydrogen halide, and a catalytic amount of a copper catalyst having the copper in an oxidation state below +2.
- -
-
-
- QUANTITATIVE DETERMINATION OF THE ELECTRONIC EFFECTS OF 3- AND 4-PYRIDAZINYL GROUPS FROM NMR SPECTRAL DATA FOR ISOMERIC AMINOPHENYL- AND PHENYLPYRIDAZINES
-
The previously unknown aminophenylpyridazines were synthesized.The inductive and resonance constants of 3- and 4-pyridazinyl groups were calculated on the basis of 1H and 13C NMR spectral data for isomeric aminophenyl- and phenylpyridazines in dimethyl sulfoxide (DMSO).
- Shkurko, O. P.,Kuznetsov, S. A.,Denisov, A. Yu.,Mamaev, V. P.
-
p. 763 - 770
(2007/10/02)
-
- Bond Fixation in Annulenes. 16. Synthesis of the 1,2-Dimethyl-3-phenylcyclooctatetraene ->/<- 1,8-Dimethyl-2-phenylcyclooctatetraene Bond Shift Isomer Pair. Probe of the Relative Size of a Flanking Phenyl Substituent by means of Racemization Kinetics
-
Two synthetic approaches to the cyclooctatetrene bond shift isomers 3 ->/octadiene to generate the cyclooctatetraene nucleus.Although 3 dominates over 4 in the equilibrium, it is possible to separate these bond shift isomers by cycloaddition with a triazolinedione.When recourse was made to the endo-bornyl-substituted dienophile, it was ultimately possible to obtain (-)-3 and to determine its rate of racemization.The data indicate that the flanking phenyl group in 3 causes significant rate retardation relative to the trimethyl derivative.This finding contrasts with the behavior of 2 which racemizes more rapidly despite an interstitial phenyl substituent.The source of these dissimilar effects has been clarified by MM2 calculations, the details of which are presented.
- Paquette, Leo A.,Gardlik, John M.,McCullough, Kevin J.,Samodral, Rodney,DeLucca, George,Ouellette, Robert J.
-
p. 7649 - 7655
(2007/10/02)
-
- Chemiluminescance of Monocyclic 3,6-Disubstituted Pyridazines: A Model for Luminol Chemiluminescence
-
Sevwral monocyclic 3,6-disubstituted pyridazines (1-5) were oxidized by molecular oxygen under the basic conditions in dimethyl sulfoxide to yield corresponding maleic acids and /or its derivatives with chemiluminescent light emission.
- Suzuki, Nobutaka,Kato, Mamoru,Sano, Kaniti,Izawa, Yasuji
-
p. 1415 - 1418
(2007/10/02)
-