2459-24-7Relevant articles and documents
Acceptorless Dehydrogenation of Hydrocarbons by Noble-Metal-Free Hybrid Catalyst System
Fuse, Hiromu,Kojima, Masahiro,Mitsunuma, Harunobu,Kanai, Motomu
, p. 2042 - 2045 (2018/04/16)
A hybrid catalysis that comprises an acridinium photoredox catalyst, a thiophosphate organocatalyst, and a nickel catalyst-enabled acceptorless dehydrogenation of hydrocarbons is reported. The cationic nickel complex played a critical role in the reactivity. This is the first example of acceptorless dehydrogenation of hydrocarbons by base metal catalysis under mild reaction conditions of visible light irradiation at room temperature.
Ruthenium-Catalyzed C-H Arylation of Diverse Aryl Carboxylic Acids with Aryl and Heteroaryl Halides
Huang, Liangbin,Weix, Daniel J.
supporting information, p. 5432 - 5435 (2016/11/04)
Ruthenium ligated to tricyclohexylphosphine or di-tert-butylbipyridine catalyzes the arylation of carboxylic acids with diverse aryl halides (iodide, bromide, and triflate; aryl and heteroaryl). In addition, arylations with 2-iodophenol formed benzochromenones, carboxylate was shown to be a stronger donor than an amide, and the arylation of a pyridine carboxylate was demonstrated. Stoichiometric studies demonstrated that the added ligand is required for reaction with the electrophile but not the C-H bond.
Facile preparation of aromatic esters from aromatic bromides with ethyl formate or DMF and molecular iodine via aryllithium
Ushijima, Sousuke,Moriyama, Katsuhiko,Togo, Hideo
experimental part, p. 4701 - 4709 (2012/07/28)
Various aromatic bromides were treated with n-BuLi and subsequently with ethyl formate, followed by the reaction with ethanol and molecular iodine in the presence of K2CO3 to provide the corresponding aromatic ethyl esters in good yields. Moreover, aromatic bromides could be transformed into the corresponding aromatic methyl esters in good yields by the treatment with n-BuLi and subsequently with DMF, followed by the reaction with methanol, molecular iodine, and K2CO3. Some aromatics could be also converted into the corresponding aromatic esters in good yields by the treatment with n-BuLi, and subsequently with ethyl formate or DMF, followed by the reaction with molecular iodine and K2CO3. The present reactions offer a novel route for the transition-metal-free, carbon-monoxide-free, and therefore environmentally benign one-pot conversion of aromatic bromides and aromatics into aromatic esters.
[IrCl(cod)]2-catalyzed direct oxidative esterification of aldehydes with alcohols
Kiyooka, Syun-ichi,Wada, Yosuke,Ueno, Mahuyu,Yokoyama, Takeshi,Yokoyama, Reiko
, p. 12695 - 12701 (2008/03/14)
[IrCl(cod)]2 catalyzed the oxidative esterification of a variety of aldehydes with methanol as a solvent in combination with K2CO3 under mild conditions (rt, 12 h). The oxidative esterification reaction of aliphatic aldehydes also took place with olefinic alcohols as reagents in toluene under similar conditions.
Dependence of intramolecular dissociative electron transfer rates on driving force in Donor-Spacer-Acceptor systems
Antonello, Sabrina,Maran, Flavio
, p. 5713 - 5722 (2007/10/03)
The voltammetric reduction of a series of phenyl-substituted 4- benzoyloxy-1-methylcyclohexyl bromides has been investigated in DMF. The reduction leads to the cleavage of the C-Br bond. On a thermodynamic ground, the direct reduction of the tertiary C-Br function is easier than that of the selected benzoates by at least 0.5 V. However, since the direct reduction of bromides is affected by a large activation overpotential, the electron is first located in the benzoate moiety. The rate constant for the following exergonic intramolecular dissociative electron transfer was determined by kinetic analysis of the cyclic voltammetry curves. The intermolecular rate constants for the reaction between the radical anions of methyl benzoates and 4-tert-butyl-1-methylcyclohexyl bromide were also determined and found to correlate very well with related literature data pertaining to tert-butyl bromide. The intramolecular rate constants were found to be more sensitive to variation of driving force than the corresponding intermolecular data. This result can be attributed to a shift of the center of the π* orbital of the radical anion donor away from the acceptor moiety, the shift being larger for the most easily reduced donors. The resulting distance increase is therefore envisaged as responsible for a more rapid rate drop, compared to the intermolecular pattern, when smaller driving forces are considered.
Carbophilic reactions of amines or methanol with thioaldehyde-S-oxides
Baudin, Jean-Bernard,Commenil, Marie-Gabrielle,Julia, Sylvestre A.,Lome, Robert,Ruel, Odile
, p. 1127 - 1141 (2007/10/03)
Correspondence and reprints Reaction of primary aliphatic amines with 7-ethylenic thioaldehyde-S-oxides la,b affords the corresponding imines 2a,b via a carbophilic addition of amine. When treated with sodium methoxide (1 equiv) and an excess of a primary amine, some methyl sulfinates 3 or 6, bearing a benzylic or allylic chain on the sulfur, are converted into imines 4 or 7. Treatment of the methyl sulfinates 3 with methoxide anion in THF or methanol generally affords a mixture of aldehydes 9, the corresponding dimethylacetals 14, a,a'-dimethoxydisulfides 10, esters 11, thionoesters 12 and methyl a-methoxysulfinates 15, whose ratios depend on the conditions. The formation of these compounds is best explained by a deprotonationelimination of the methyl sulfinates into the corresponding thioaldehyde-S-oxides; which then undergo a carbophilic addition of methoxide anion or methanol. Several possible reaction paths from the so-formed a-methoxysulfenate anions IX are discussed for their conversion into the final compounds. unsaturated sulfinic ester / elimination / thioaldehyde-S-oxide / imine / aldehyde / a,a -dimethoxydisulflde / thionoester / methyl u-methoxysulflnate Eisevier,.
A New Indirect Application of Aggregative Activation: Synthesis of Esters by Cobalt-Catalyzed Carbonylation of Aryl, Heterocyclic, and Vinyl Halides under Atmospheric Pressure
Marchal, Joel,Bodiguel, Jacques,Fort, Yves,Caubere, Paul
, p. 8336 - 8340 (2007/10/02)
Sun lamp illuminated alkoxycarbonylation of aryl, heteroaryl, and vinyl halides was performed under atmospheric pressure of CO in the presence of a cobalt catalyst in situ generated from Co(OAc)2.Illunination through a Pyrex flask was sufficient to catalyze the reaction.This process avoids the use of Co2(CO)8 and excess CH3I, which were required in the earlier procedure.A SRN1 mechanism is proposed.
Cobalt-catalyzed methoxycarbonylation of naphthalene mono- and di-sulfonates to naphthalene mono- and di-esters
Cometti, Giuseppe,vosel, Annick Du,Francalanci, Franco,Santi, Roberto,Cabri, Walter,Foa, Marco
, p. C13 - C14 (2007/10/02)
The methoxycarbonylation of naphthalene mono- and di-sulfonates under mild reaction conditions catalyzed by cobalt complexes generated in situ from either -/Me2SO4 or -/BrCH2COOEt is reported.
Electrochemical oxidation of ketones in methanol in the presence of alkali metal bromides
Nikishin, Gennady I.,Elinson, Michail N.,Makhova, Irina V.
, p. 895 - 905 (2007/10/02)
Electrochemical oxidation of methyl ketones in methanoi in the presence of alkali metal bromides affords methyl carboxylates. Benzyl alkyl ketones are transformed under similar conditions into methyl 3-phenylalkanoates, while ketones lacking σ-benzyl or σ-methyl group are oxidized into σ-hydroxyketals.
OXIDATION OF ENOL ETHERS BY METAL(VI)OXIDE DIPEROXIDES
Curci, Ruggero,Lopez, Luigi,Troisi, Luigino,Rashid, S. M. Khaledur,Schaap, A. Paul
, p. 3145 - 3148 (2007/10/02)
Alkoxy(aryl) adamantylidenes react with chromium(VI) or molybdenum(VI) oxide diperoxides in CHCl3 under argon yielding the corresponding 1,2-dioxetanes and/or carbonyl products derived from the fragmentation of the dioxetanes.The reaction most likely proceeds via preliminary epoxidation of the unsaturated substrates.
