937-55-3Relevant academic research and scientific papers
Ruthenium-catalysed domino hydroformylation-hydrogenation-esterification of olefins
Beller, Matthias,Dühren, Ricarda,Franke, Robert,Jackstell, Ralf,Kucmierczyk, Peter,Schneider, Carolin
, p. 5777 - 5780 (2021/09/10)
A novel catalytic domino reductive hydroformylation-esterification of olefins is reported. The optimal protocol makes use of an inexpensive Ru carbonyl catalyst and uses acetic acid as both solvent and reactant. In general, moderate to good yields are obtained using aliphatic or aromatic olefins including industrially relevant di-isobutene. This atom-efficient catalytic transformation provides straightforward access to various acetate esters from unfunctionalized olefins.
Tropolonate salts as acyl-transfer catalysts under thermal and photochemical conditions: Reaction scope and mechanistic insights
Mai, Binh Khanh,Koenigs, Rene M.,Nguyen, Thanh Vinh,Lyons, Demelza J.M.,Empel, Claire,Pace, Domenic P.,Dinh, An H.
, p. 12596 - 12606 (2020/11/18)
Acyl-transfer catalysis is a frequently used tool to promote the formation of carboxylic acid derivatives, which are important synthetic precursors and target compounds in organic synthesis. However, there have been only a few structural motifs known to efficiently catalyze the acyl-transfer reaction. Herein, we introduce a different acyl-transfer catalytic paradigm based on the tropolone framework. We show that tropolonate salts, due to their strong nucleophilicity and photochemical activity, can promote the coupling reaction between alcohols and carboxylic acid anhydrides or chlorides to give products under thermal or blue light photochemical conditions. Kinetic studies and density functional theory calculations suggest interesting mechanistic insights for reactions promoted by this acyl-transfer catalytic system.
Esterification of Tertiary Amides by Alcohols Through C?N Bond Cleavage over CeO2
Toyao, Takashi,Nurnobi Rashed, Md.,Morita, Yoshitsugu,Kamachi, Takashi,Hakim Siddiki,Ali, Md. A.,Touchy,Kon, Kenichi,Maeno, Zen,Yoshizawa, Kazunari,Shimizu, Ken-ichi
, p. 449 - 456 (2018/09/11)
CeO2 has been found to promote ester forming alcoholysis reactions of tertiary amides. The present catalytic system is operationally simple, recyclable, and it does not require additives. The esterification process displays a wide substrate scope (>45 examples; up to 93 % isolated yield). Results of a density functional theory (DFT) study combined with in situ FT-IR observations indicate that the process proceeds through rate limiting addition of a CeO2 lattice oxygen to the carbonyl group of the adsorbed acetamide species with energy barrier of 17.0 kcal/mol. This value matches well with experimental value (17.9 kcal/mol) obtained from analysis of the Arrhenius plot. Further studies by in situ FT-IR and temperature programmed desorption using probe molecules demonstrate that both acidic and basic properties are important, and consequently, CeO2 showed the best performance for the C?N bond cleavage reaction.
Iron-Catalysed Remote C(sp3)?H Azidation of O-Acyl Oximes and N-Acyloxy Imidates Enabled by 1,5-Hydrogen Atom Transfer of Iminyl and Imidate Radicals: Synthesis of γ-Azido Ketones and β-Azido Alcohols
Torres-Ochoa, Rubén O.,Leclair, Alexandre,Wang, Qian,Zhu, Jieping
, p. 9477 - 9484 (2019/05/21)
In the presence of a catalytic amount of iron(III) acetylacetonate [Fe(acac)3], the reaction of structurally diverse ketoxime esters with trimethylsilyl azide (TMSN3) afforded γ-azido ketones in good to excellent yields. This unprecedented distal γ-C(sp3)?H bond azidation reaction went through a sequence of reductive generation of an iminyl radical, 1,5-hydrogen atom transfer (1,5-HAT) and iron-mediated redox azido transfer to the translocated carbon radical. TMSN3 served not only as a nitrogen source to functionalise the unactivated C(sp3)?H bond, but also as a reductant to generate the catalytically active FeII species in situ. Based on the same principle, a novel β-C(sp3)?H functionalisation of alcohols via N-acyloxy imidates was subsequently realised, leading, after hydrolysis of the resulting ester, to β-azido alcohols, which are important building blocks in organic and medicinal chemistry.
Lipase-mediated selective acetylation of primary alcohols in ethyl acetate
de Souza, Ernane C.,Romero-Ortega, Moises,Olivo, Horacio F.
supporting information, p. 287 - 290 (2017/12/29)
An environmental friendly process to selectively acetylate primary alcohols was demonstrated. The esterification process consists of treatment of a primary alcohol in the presence of immobilized C. antarctica lipase (Novozyme-435) in ethyl acetate at room temperature. Primary alcohols were acetylated in the presence of secondary alcohols and phenols.
Light-enhanced acid catalysis over a metal-organic framework
Xu, Caiyun,Sun, Keju,Zhou, Yu-Xiao,Ma, Xiao,Jiang, Hai-Long
supporting information, p. 2498 - 2501 (2018/03/21)
A Br?nsted acid-functionalized metal-organic framework (MOF), MIL-101-SO3H, was prepared for acid-engaged esterification reactions. Strikingly, for the first time, the MOF exhibits significantly light-enhanced activity and possesses excellent activity and recyclability, with even higher activity than H2SO4 under light irradiation.
Supported palladium nanoparticles as switchable catalyst for aldehyde conjugate/s and acetate ester syntheses from alcohols
Kumar, Sandeep,Chaudhary, Abha,Bandna,Bhattacherjee, Dhananjay,Thakur, Vandna,Das, Pralay
supporting information, p. 3242 - 3245 (2017/07/12)
Polymer-supported Pd(0) (Pd@PS) nanoparticles (NPs) were explored as a switchable catalyst for oxidative aldehyde conjugate/s (AC/s) and acetate esters (AEs) syntheses from alcohols. Using the same substrates, the catalyst in the presence of oxygen and K2CO3 participated in AC/s synthesis, and in the presence of traces of air and NaOtBu, unusual AEs products were obtained.
Novel access to carbonyl and acetylated compounds: The role of the tetra-: N -butylammonium bromide/sodium nitrite catalyst
Sheykhan, Mehdi,Moafi, Hadi Fallah,Abbasnia, Masoumeh
, p. 51347 - 51355 (2016/06/09)
A novel aerobic oxidation of alcohols without the use of any oxidants was developed. An equimolar catalytic mixture of tetra-n-butylammonium bromide and sodium nitrite catalyzes the aerobic selective oxidation of benzylic alcohols under oxidant-free, base-free and metal-free conditions. The mild reaction conditions allow oxidation of a wide range of benzylic alcohols, chemo-selectively to their carbonyl compounds (68-93% isolated yields). More importantly, high selectivity among different kinds of alcohols (aromatic vs. aliphatic alcohols, primary vs. secondary alcohols as well as alcohols having neutral rings vs. electron-deficient rings) is available by this approach. The method surprisingly switched over to be an efficient acetylation approach in the case of aliphatic alcohols without the use of any transition metal, phosphorous or other toxic reagents or any need for using toxic acyl halides, sulfonyl halides, anhydrides, etc. by the use of only acetic acid as a reagent.
Oxidative "reverse-esterification" of ethanol with benzyl/alkyl alcohols or aldehydes catalyzed by supported rhodium nanoparticles
Guha, Nitul Ranjan,Sharma, Saurabh,Bhattacherjee, Dhananjay,Thakur, Vandna,Bharti, Richa,Reddy, C. Bal,Das, Pralay
supporting information, p. 1206 - 1211 (2016/03/09)
A very unusual role of polystyrene stabilized rhodium (Rh@PS) nanoparticles as a supported catalyst is described for "reverse-esterification" of ethanol with benzyl/alkyl alcohols or aldehydes. Faster and selective oxidation of ethanol to acetaldehyde and H2 under Rh@PS catalyzed conditions which restricted further oxidation of benzyl/alkyl alcohols and their in situ reaction gave the corresponding acetate esters following the dehydrogenative-coupling approach. A hitherto redox dehydrogenative-coupling of ethanol and aldehydes has also been explored for the same acetate ester synthesis under Rh@PS catalyzed conditions.
Transition metal nanoparticles stabilized by ammonium salts of hyperbranched polystyrene: effect of metals on catalysis of the biphasic hydrogenation of alkenes and arenes
Gao, Lei,Kojima, Keisuke,Nagashima, Hideo
, p. 6414 - 6423 (2015/08/18)
Abstract Hyperbranched polystyrene bearing ammonium salts (HPS-NR3+Cl-) behaves as an excellent stabilizer of ruthenium, rhodium, iridium, palladium, and platinum nanoparticles from 1 to 3 nm in size uniformly dispersed in the polymer matrix. The catalytic performance of the resulting metal-polymer composites, M@HPS-NR3+Cl-, is dependent on the metal. This dependence was investigated by assessing the hydrogenation of alkenes and arenes. The utility of M@HPS-NR3+Cl- as reusable catalysts in aqueous/organic biphasic systems was demonstrated by examining the catalysis of the hydrogenation of aromatic compounds containing various functional groups by Ru@HPS-NR3+Cl-.
