637-64-9Relevant academic research and scientific papers
Insight into the Mechanism of the Acylation of Alcohols with Acid Anhydrides Catalyzed by Phosphoric Acid Derivatives
Hayashi, Hiroyuki,Yasukochi, Shotaro,Sakamoto, Tatsuhiro,Hatano, Manabu,Ishihara, Kazuaki
, p. 5197 - 5212 (2021/04/12)
Insight into the mechanism of a safe, simple, and inexpensive phosphoric acid (H3PO4)-catalyzed acylation of alcohols with acid anhydrides is described. The corresponding in situ-generated diacylated mixed anhydrides, unlike traditionally proposed monoacylated mixed anhydrides, are proposed as the active species. In particular, the diacylated mixed anhydrides act as efficient catalytic acyl transfer reagents rather than as Br?nsted acid catalysts simply activating acid anhydrides. Remarkably, highly efficient phosphoric acid (1-3 mol %)-catalyzed acylation of alcohols with acid anhydrides was achieved and a 23 g scale synthesis of an ester was demonstrated. Also, phosphoric acid catalyst was effective for synthetically useful esterification from carboxylic acids, alcohols, and acid anhydride. Moreover, with regard to recent developments in chiral 1,1′-bi-2-naphthol (BINOL)-derived phosphoric acid diester catalysts toward asymmetric kinetic resolution of alcohols by acylation, some phosphate diesters were examined. As a result, a 31P NMR study and a kinetics study strongly supported not only the acid-base cooperative mechanism as previously proposed by other researchers but also the mixed anhydride mechanism as presently proposed by us.
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.
Simultaneous hydrogenation and acid-catalyzed conversion of the biomass-derived furans in solvents with distinct polarities
Hu, Xun,Kadarwati, Sri,Song, Yao,Li, Chun-Zhu
, p. 4647 - 4656 (2016/01/29)
Furfural and 5-hydroxymethylfurfural (HMF), the two typical biomass-derived furans, can be converted into biofuels and value-added chemicals via hydrogenation or acid catalysis or both. The potential competition between the hydrogenation and the catalyzed-conversion of HMF and furfural has been investigated with Pd/C and Amberlyst 70 as the catalysts at 170°C in various solvents. In water, the hydrogenation of HMF or the derivatives of HMF could take place, but the acid-catalyzed conversion of HMF to the diketones (2,5-hexanedione) was the dominant reaction pathway. On the contrary, with ethanol as the solvent, the full hydrogenation of HMF to 2,5-tetrahydrofurandimethanol was the dominant route, and the acid-catalyzed routes became insignificant. The efficiency for hydrogenation of HMF was much higher in ethanol than in water. As for furfural, its hydrogenation proceeded more efficiently in the polar solvents (i.e. ethanol, diethyl ether) than in non-polar solvents (i.e. toluene): a polar solvent tended to favor the hydrogenation of the furan ring in furfural over that of the carbonyl group in the same furfural.
Oxidative acetoxylactonisation of alkenoic acids using H2O2 in acetic acid catalysed by KI
Zhou, Zhong-Shi,He, Xue-Han
, p. 518 - 520 (2015/11/27)
In the presence of a catalytic amount of KI in combination with H2O2, a convenient catalytic procedure has been developed for the direct preparation of acetoxylactones from alkenoic acids in acetic acid at room temperature which provides the corresponding cyclic products in good yields. This novel methodology mediated by an in situ generated hypervalent iodine intermediate extends the catalytic application of KI in organic synthesis.
Al(OTf)3 as a highly efficient catalyst for the rapid acetylation of alcohols, phenols and thiophenols under solvent-free conditions
Kamal, Ahmed,Khan, M. Naseer A.,Reddy, K. Srinivasa,Srikanth,Krishnaji
, p. 3813 - 3818 (2008/02/06)
Aluminium triflate (0.01-0.1 mol %) was found to be an efficient catalyst for the acylation of alcohols, phenols, thiols and sugars with acetic anhydride in high yields under solvent-free conditions in a short reaction time at room temperature. Racemization of optically active alcohols and epimerization of sugars were not observed. The acylation efficacy of various acyl donors was also investigated.
Bi(III) halides as efficient catalysts for the O-acylative cleavage of tetrahydrofurans: An expeditious entry to tetralins
Coles, Simon J.,Costello, James F.,Draffin, William N.,Hursthouse, Michael B.,Paver, Simon P.
, p. 4447 - 4452 (2007/10/03)
The mild (DCM/20°C), quantitative, regioselective, O-acylative cleavage of tetrahydrofurans using organic acid halides with catalytic Bi(III) halides is reported. X-ray crystallography is used to rationalise the failure of the reaction in the case of certain crowded acid chlorides, and a useful aspect of chemoselectivity is revealed. The synthetic potential of this reaction is illustrated with a highly efficient O-acylative cleavage/intramolecular alkylation approach to tetralins.
Highly selective one-pot conversion of THP and MOM ethers to acetates by indium triiodide-catalysed deprotection and subsequent transesterification by ethyl acetate
Ranu, Brindaban C.,Hajra, Alakananda
, p. 2262 - 2265 (2007/10/03)
The chemoselective one-pot conversion of tetrahydropyranyl (THP) and methoxymethyl (MOM) ethers of primary alcohols to the corresponding acetates was presented. It was done using indium triiodide-catalysed deprotection and subsequent acetylation by ethyl acetate through a transesterification process. The advantages offered by the method included operational simplicity, 'green' methodology involving no toxic or hazardous chemicals and high yield.
Efficient liquid phase acylation of alcohols over basic ETS-10 molecular sieves
Waghmode, Suresh B.,Thakur, Vinay V.,Sudalai, Arumugam,Sivasanker, Subramanian
, p. 3145 - 3147 (2007/10/03)
Acylation of alcohols with acetic acid can be carried out efficiently in the liquid phase over microporous titanosilicate ETS-10-type catalysts. The reaction was studied over ETS-10 exchanged with, Li, Na, K, Rb, Cs, Ba and H ions. Activity for acylation of primary alcohols depends on the exchanged alkali ion and increases in the order LiNaKBa～H～Rb～Cs-ETS-10. These molecular sieves are also suitable for the acylation of secondary alcohols and esterification with long chain carboxylic acids.
Heterogeneous catalysis in acetylation of alcohols and phenols promoted by zirconium sulfophenyl phosphonate
Curini, Massimo,Epifano, Francesco,Marcotullio, Maria Carla,Rosati, Ornelio,Rossi, Monia
, p. 1319 - 1329 (2007/10/03)
Layered zirconium sulfophenyl phosphonate was found to be an efficient heterogeneous catalyst for the acetylation of alcohols and phenols.
Nafion-H catalyzed acetylation of alcohols
Kumareswaran,Pachamuthu,Vankar
, p. 1652 - 1654 (2007/10/03)
A wide variety of alcohols, some containing acid sensitive groups also, underwent smooth acetylation with acetic anhydride upon catalysis with Nation-H, a solid acid catalyst, which could be recovered and used again.
