106-32-1Relevant articles and documents
The first Negishi cross-coupling reaction of two alkyl centers utilizing a Pd-N-heterocyclic carbene (NHC) catalyst
Hadei, Niloufar,Kantchev, Eric Assen B.,O'Brien, Christopher J.,Organ, Michael G.
, p. 3805 - 3807 (2005)
(Chemical Equation Presented) The development of an NHC-based system capable of cross-coupling sp3-sp3 centers in high yield has been a long-standing challenge. This communication describes the use of a Pd-NHC catalytic system that achieves room-temperature Negishi cross-couplings of unactivated, primary bromides and alkyl organozinc reagents with a variety of functionality.
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Collman et al.
, p. 249 (1973)
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Ultrasound-assisted synthesis of aliphatic acid esters at room temperature
Hobuss, Cristiane B.,Venzke, Dalila,Pacheco, Bruna S.,Souza, Alexander O.,Santos, Marco A.Z.,Moura, Sidnei,Quina, Frank H.,Fiametti, Karina G.,Vladimir Oliveira,Pereira, Claudio M.P.
, p. 387 - 389 (2012)
This work describes the ultrasound-assisted synthesis of saturated aliphatic esters from synthetic aliphatic acids and either methanol or ethanol. The products were isolated in good yields after short reaction times under mild conditions.
Oxidative esterification of aliphatic aldehydes and alcohols with ethanol over gold nanoparticle catalysts in batch and continuous flow reactors
Taketoshi,Ishida,Murayama, Toru,Honma, Tetsuo,Haruta, Masatake
, (2019)
Selective esterification of aliphatic aldehydes and alcohols with ethanol in the absence of a base is a more difficult reaction than that with methanol. Gold nanoparticles on ZnO were found to catalyze the oxidative esterification of octanal to ethyl octanoate with high selectivity. In addition, it was found that Au/ZnO was the most effective catalyst for yielding the desired ethyl ester without a base by direct esterification of 1-octanol with ethanol. As far as we know, this is the first report on oxidative esterification to give aliphatic ethyl esters from less reactive aliphatic alcohols and aldehydes without a base. The optimal size of gold NPs ranged from 2 to 6 nm and the presence of Au(0) was indispensable for this reaction. Au/ZnO exhibited the highest catalytic activity in both batch and flow reactors. The conversion was maintained for more than 20 h with 95% selectivity to the desired ethyl ester in the flow system.
Tandem one-pot conversion of aldehydes into ethyl esters
Siler, Patrick J.,Chill, Samuel T.,Mebane, Robert C.
, p. 1247 - 1250 (2011)
A facile one-pot synthesis of ethyl esters from aldehydes has been developed. This tandem process involves the formation of a nitrile intermediate obtained from the reaction of an aldehyde with hydroxylamine hydrochloride in dimethylsulfoxide (DMSO) at 100°C and the subsequent reaction of the nitrile with ethanol and sulfuric acid at 130°C. The resulting ethyl ester products were produced in good yields (65-90%) and high purity (>95%).
Towards the rational design of palladium-N-heterocyclic carbene catalysts by a combined experimental and computational approach
O'Brien, Christopher J.,Kantchev, Eric Assen B.,Chass, Gregory A.,Hadei, Niloufar,Hopkinson, Alan C.,Organ, Michael G.,Setiadi, David H.,Tang, Ting-Hua,Fang, De-Cai
, p. 9723 - 9735 (2005)
A combined experimental and computational approach towards the development of Pd-NHC catalysts is described. A range of benzimidazolylidinium ligands incorporating electron-rich and electron-poor substituents were prepared and evaluated in the Suzuki reaction. The most electron-rich ligand showed the highest catalytic activity. Based on this information, the first alkyl-alkyl Negishi cross-coupling reaction protocol was developed. Evaluation of N,N′-diaryl-(4,5-dihydro)imidazolylilidinium ligands showed a strong dependence on the steric topography around the metal centre. A computational study of the most active ligand in the Negishi reaction, its Pd(0) and PdCl 2-complexes and related structures were modelled at the B3LYP/DZVP and HF/3-21G levels of theory. The potential energy hypersurfaces flattened with increase in ligand size. Binding energies were computed for carbene/Pd(0) adducts (in the range ~31-40 kcal mol-1), roughly double that for PH3 (~16 kcal mol-1). Weak intramolecular interactions were found using AIM analyses.
Selective esterification reaction involving hexaalkyl guanidinium chloride catalyst
Gros,Le Perchec,Gauthier,Senet
, p. 1835 - 1842 (1993)
A new efficient and selective esterification reaction of carboxylic acids with chloroformates is described using silica-supported catalyst (PBGSiCl). The chemioselectivity of the reaction was high particularly for sterically hindered carboxylic acids supported by a single pathway reaction.
"Nafion"-functionalized mesoporous MCM-41 silica shows high activity and selectivity for carboxylic acid esterification and Friedel-Crafts acylation reactions
Alvaro, Mercedes,Corma, Avelino,Das, Debasish,Fornes, Vicente,Garcia, Hermenegildo
, p. 48 - 55 (2005)
Hybrid organic-inorganic MCM-41 silicas functionalized with perfluoroalkylsulfonic acid groups analogous to that of Nafion were prepared in a simple single step by a condensation reaction between surface silanol groups of the mesoporous silicas and 1,2,2-trifluoro-2-hydroxy-1-trifluoromethyl-ethane sulfonic acid Beta-sultone. The catalysts showed very high activity for the esterification of long-chain fatty acids with ethanol and high-molecular-weight alcohols with essentially complete selectivity at high conversion (>95%). Acylation of anisole was also possible, with high selectivity for 4-methoxyacetophenone. The catalysts showed more activity conversion than commercial Nafion-silica composite catalysts.
Tin-free reductive photochemical carboxymethylation of olefins with α- alkylthioacetates
Deng, Lisa X.,Kutateladze, Andrei G.
, p. 7829 - 7832 (1997)
An efficient tin-free reductive photochemical carboxymethylation of olefins with α-alkylthioacetates is developed, which (a) is an experimentally simple technique furnishing substituted derivatives of fatty acids in moderate to good yields, (b) is compatible with polar/protic functional groups and solvents, (c) does not require a special reducing reagent, (d) is fairly insensitive to the presence of dissolved oxygen and, generally, does not require degassing prior to irradiation. The critical feature of the mechanism is the 'reluctance' of short-lived MeS' to group- transfer, resulting in hydrogen abstraction from the media.
Stability of sulfated zirconia and the nature of the catalytically active species in the transesterification of triglycerides
Suwannakarn, Kaewta,Lotero, Edgar,Goodwin Jr., James G.,Lu, Changqing
, p. 279 - 286 (2008)
Sulfated zirconia (SZ) exhibits remarkable activity for various hydrocarbon reactions under mild conditions and is of interest for biodiesel synthesis. Nevertheless, to date no detailed study has addressed its activity and stability in liquid polar media such as alcohols, although a number of papers have suggested the possibility for some sulfur leaching. This paper presents an investigation into the activity and stability of a commercial SZ catalyst for the liquid-phase transesterification of triglycerides at 120 °C. The kinetics of tricaprylin (TCP) transesterification with a series of aliphatic alcohols (methanol, ethanol, and n-butanol) were investigated at 120 °C and 6.8 atm in a Parr batch reactor. It was found that the catalytic activity for TCP conversion decreased as the number of carbons in the alkyl chain of alcohol increased, most likely as a result of increased steric hindrance. The SZ catalyst exhibited significant activity loss with subsequent reaction cycles. The characterization of used catalysts after their exposure to various alcohols at 120 °C showed that the SO2-4 moieties in SZ were permanently removed. The SO2-4 species were leached out, most likely as sulfuric acid, which further reacted with alcohols to form monoalkyl and dialkyl sulfate species, as demonstrated by 1H NMR studies. This was in essence the main route for catalyst deactivation. Our findings conclusively demonstrate for the first time that in alcoholic-liquid media at higher temperatures, SZ deactivates by leaching of its active sites, most likely leading to significant homogeneous rather than heterogeneous catalysis.
Preparation process of capryloyl hydroxamic acid
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Paragraph 0034-0045, (2021/01/30)
The invention relates to the field of chemical synthesis, and particularly discloses a preparation process of capryloyl hydroxamic acid, which comprises the following steps: preparing ethyl n-caprylate, and preparing the capryloyl hydroxamic acid, wherein the ethyl n-caprylate is prepared by the following steps: mixing 1-1.5 kg of n-caprylic acid with 0.35-0.7 kg of ethanol, adding solid superacid, performing heating reflux for 5-7 hours, filtering to obtain precipitate and filtrate, and performing reduced pressure distillation on the filtrate to obtain the ethyl n-caprylate, and the obtainedprecipitate is washed and roasted to obtain the solid superacid, and the solid superacid is recycled to the preparation step of the ethyl n-caprylate for use. By using the solid superacid catalyst, the environmental friendliness of the esterification reaction in the n-capryloyl hydroxamic acid preparation process is improved.
Copper catalyzed C(sp3)-H bond alkylation via photoinduced ligand-to-metal charge transfer
Treacy, Sean M.,Rovis, Tomislav
supporting information, p. 2729 - 2735 (2021/03/01)
Utilizing catalytic CuCl2 we report the functionalization of numerous feedstock chemicals via the coupling of unactivated C(sp3)-H bonds with electron-deficient olefins. The active cuprate catalyst undergoes Ligand-to-Metal Charge Transfer (LMCT) to enable the generation of a chlorine radical which acts as a powerful hydrogen atom transfer reagent capable of abstracting strong electron-rich C(sp3)-H bonds. Of note is that the chlorocuprate catalyst is an exceedingly mild oxidant (0.5 V vs SCE) and that a proposed protodemetalation mechanism offers a broad scope of electron-deficient olefins, offering high diastereoselectivity in the case of endocyclic alkenes. The coupling of chlorine radical generation with Cu reduction through LMCT enables the generation of a highly active HAT reagent in an operationally simple and atom economical protocol.