104-21-2Relevant academic research and scientific papers
Microwave-assisted NiCl2 promoted acylation of alcohols
Constantinou-Kokotou, Violetta,Peristeraki, Anna
, p. 4227 - 4232 (2004)
A microwave oven acylation of alcohols by carboxylic acid anhydrides has been developed. NiCl2 has been proven an efficient catalyst for the acylation of primary, secondary, and tertiary alcohols and phenols under microwave conditions.
The Mechanism of Enzymatic and Biomimetic Oxidations of Aromatic Sulfides and Sulfoxides
Baciocchi, Enrico,Lanzalunga, Osvaldo,Marconi, Francesco
, p. 9771 - 9774 (1994)
Biomimetic and enzymatic oxidations of benzyl sulfides and sulfoxides lead to products (sulfoxides or sulfones) different from those obtained with bona fide electron transfer oxidations (products of C-H and/or C-S bond cleavage), which suggests the operation of an oxygen transfer machanism.
Synthesis, Characterisation, and Determination of Physical Properties of New Two-Protonic Acid Ionic Liquid and its Catalytic Application in the Esterification
Shahnavaz, Zohreh,Zaharani, Lia,Khaligh, Nader Ghaffari,Mihankhah, Taraneh,Johan, Mohd Rafie
, p. 165 - 172 (2021)
A new ionic liquid was synthesised, and its chemical structure was elucidated by FT-IR, 1D NMR, 2D NMR, and mass analyses. Some physical properties, thermal behaviour, and thermal stability of this ionic liquid were investigated. The formation of a two-protonic acid salt namely 4,4′-trimethylene-N,N′-dipiperidinium sulfate instead of 4,4′-trimethylene-N,N′-dipiperidinium hydrogensulfate was evidenced by NMR analyses. The catalytic activity of this ionic liquid was demonstrated in the esterification reaction of n-butanol and glacial acetic acid under different conditions. The desired acetate was obtained in 62-88 % yield without using a Dean-Stark apparatus under optimal conditions of 10 mol-% of the ionic liquid, an alcohol to glacial acetic acid mole ratio of 1.3: 1.0, a temperature of 75-100°C, and a reaction time of 4 h. α-Tocopherol (α-TCP), a highly efficient form of vitamin E, was also treated with glacial acetic acid in the presence of the ionic liquid, and O-acetyl-α-tocopherol (Ac-TCP) was obtained in 88.4 % yield. The separation of esters was conducted during workup without the utilisation of high-cost column chromatography. The residue and ionic liquid were used in subsequent runs after the extraction of desired products. The ionic liquid exhibited high catalytic activity even after five runs with no significant change in its chemical structure and catalytic efficiency.
Acetylation of alcohols and phenols under solvent-free conditions using copper zirconium phosphate
Hajipour, Abdol R.,Karimi, Hirbod
, p. 1982 - 1989 (2014)
Copper zirconium phosphate nanoparticles have been used as an efficient catalyst for the acetylation of a wide range of alcohols and phenols with acetic anhydride in good to excellent yields under solvent-free conditions. The steric and electronic properties of the different substrates had a significant influence on the reaction conditions required to achieve the acetylation. The catalyst used in the current study was characterized by inductively-coupled plasma optical emission spectroscopy, energy dispersive spectroscopy, X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, and transmission electron microscopy. These analyses revealed that the interlayer distance in the catalyst increased from 7.5 to 8.0 ? when Cu2+ was intercalated between the layers, whereas the crystallinity of the material was reduced. This nanocatalyst could also be recovered and reused at least six times without any discernible decrease in its catalytic activity. This new method for the acetylation of alcohols and phenols has several key advantages, including mild and environmentally friendly reaction conditions, as well as good to excellent yields and a facile work-up.
Synthesis and characterization of MCM-41@XA@Ni(II) as versatile and heterogeneous catalyst for efficient oxidation of sulfides and acetylation of alcohols under solvent-free conditions
Nazarzadeh, Somayeh,Ghorbani-Choghamarani, Arash,Tahanpesar, Elham
, p. 649 - 659 (2018)
Herein, Ni(II) immobilized on modified mesoporous silica MCM-41 was designed and synthesized via a facile sequential strategy. The structure of the catalyst was characterized by X-ray diffraction. The thermal property of the as-synthesized materials was studied using thermogravimetric-differential thermal analysis. The average particles size and morphology of MCM-41@XA@Ni(II) were investigated using scanning electron microscopy and transmission electron microscopy. This nanostructure catalyst was effective for the selective oxidation of sulfides and acetylation of alcohols in solvent-free conditions. The easy recyclability of the catalyst and their complete chemoselectivity toward the sulfur group of substrates in the oxidation of sulfides are important “green” attributes of this catalyst.
Side-Chain Oxidation of α-Substituted 4-Methoxytoluenes by Potassium 12-Tungstocobalt(III)ate. The Effect of α-Substituents on the Formation and Deprotonation of the Intermediate Cation Radicals
Baciocchi, Enrico,Bietti, Massimo,Mattioli, Mario
, p. 7106 - 7110 (1993)
A kinetic study of the side-chain oxidation of α-substituted 4-methoxytoluenes (4-MeOPhCH2R, R = H, Me, OH, OMe, OAc, CN) by K5Co(III)W12O40*11H2O (Co(III)W) in AcOH/H2O (55:45) has been carried out.The reactions follow complex kinetics, suggesting that both the electron transfer and the radical cation deprotonation steps influence the reaction rate.A careful kinetic analysis has allowed the determination of the values of k1, the rate constant for the electron transfer step, and of k-1/k2, the ratio between the rate constant of the back electron transfer and the one of the deprotonation of the cation radical.A satisfactory Marcus correlation between k1 and the free energy changes for the electron-transfer step is obtained, affording a value of 41 kcal mol-1 for the intrinsic barrier of the process.Therefrom a value of 57 kcal mol-1 for the reorganization energy pertaining to the conversion of 4-MeOPhCH2R into 4-MeOPhCH2R(1+) can be calculated.By assuming that k-1 is constant (the back electron transfer should be diffusion controlled for all substrates), the relative rate constants for the deprotonation of the radical cations, k2(R)/k2(H), can be obtained by the (k-1/k2)H/(k-1/k2)R ratios.It has been observed that k2(R)/k2(H) increases by increasing the oxidation potential of the substrate, whereas the reverse occurs with k1.The effect on k1 is, however, much larger than on k2(R)/k2(H), which allows us to conclude that α-substituents influence the oxidation rate of 4-methoxytoluene mainly through the effect exerted on the rate of the electron-transfer step.
CuSO4 as a mild, green, and efficient catalyst for the one-pot conversion of THP ethers to acetates
Asadolah, Karim,Heravi, Majid M.
, p. 867 - 869 (2007)
An efficient direct conversion of THP ethers into the corresponding acetates was achieved with acetic anhydride in the presence of CuSO4 ? 5H2O as an available and green catalyst in high yields.
Molecular iodine in ionic liquid: A green catalytic system for esterification and transesterification
Ren, Yiming,Cai, Chun
, p. 1670 - 1676 (2010)
Esterification of carboxylic acids and transesterification of-ketoesters with alcohols have been developed using a catalytic amount of iodine in polyethylene glycol (PEG) ionic liquid (IL 1000) to afford the corresponding esters in good yields. By simple separation of the ionic-liquid phase containing the iodine, the system of I2/IL 1000 can be reused several times. Copyright
Photoredox-Catalyzed Benzylic Esterification via Radical-Polar Crossover
Maeda, Bumpei,Sakakibara, Yota,Murakami, Kei,Itami, Kenichiro
, p. 5113 - 5117 (2021)
Photoredox-catalyzed C-O bond formation reactions are reported. The decarboxylative esterification reaction allows the conversion of a variety of arylacetic acids into the corresponding benzyl carboxylates. Furthermore, the use of (diacetoxyiodo)benzene allows the conversion of the benzylic C-H bond through hydrogen atom transfer. The reactions were applied to the divergent transformation of pharmaceuticals via decarboxylative or C-H esterification reactions.
Transprotection of silyl ethers of nucleosides in FeCl3 based ionic liquids
Harjani, Jitendra R.,Nara, Susheel J.,Salunkhe, Manikrao M.,Sanghvi, Yogesh S.
, p. 819 - 822 (2005)
Ionic liquid mediated deprotection of tert-butyldimethyl silyl (TBDMS) ethers derived from various primary and secondary alcohols have been studied and the reaction conditions optimized. Deprotection of the silyl ethers in FeCl3 based ionic liquids in presence of acetic anhydride yielded the acetate esters of the corresponding alcohols in good yields. The transprotection methodology was extended to the silyl ethers of nucleosides to yield the corresponding acetylated products. Copyright Taylor & Francis, Inc.
