35300-54-0Relevant academic research and scientific papers
Optimization of phase-transfer catalysts designed from calix[4]arene
Araki,Yanagi,Shinkai
, p. 6763 - 6772 (1993)
To optimize the calix[4]arene structure for a phase-transfer catalyst, we modified the upper rim with lipophilic tert-octyl groups and the lower rim with O(CH2CH2O)(m)Me (m = 1, 2, and 3). Through two-phase solvent extraction, 1
Facile construction of thermo-responsive Pickering emulsion for esterification reaction in phase transfer catalysis system
Lei, Manjun,Shen, Yifeng,Sun, Jie,Yang, Lei,Yang, Lihui,Zhao, Qiangqiang,Zhao, Xiao
, (2020/12/30)
In this paper, a thermo-responsive Pickering emulsion (PE) is constructed for the esterification reaction in the phase transfer catalysis (PTC) system. Silica nanoparticle modified by alkyl polyoxyethylene ether and tetrabutylammonium bromide (TBAB) is the highly efficient thermo-responsive Pickering emulsifier to stabilize the diisopropyl ketone-in-water emulsion. PEs can keep stable at room temperature for 3 days and demulsify only in the condition of elevated temperature and agitation, which causes the easy product separation and aqueous phase recycling. The adsorption of TBA+ and nonionic surfactant via electrostatic interaction and hydrogen bonding, respectively, can increase the hydrophobicity and the emulsifying capacity of silica nanoparticle. The ion-pair of TBA+ and reactant anion is generated and can be transferred into the organic phase, initiating the bond-forming reaction. The modifying effect of polyoxyethylene ether is weakened with the increase of temperature due to the loss of the hydrogen bonding interaction, resulting in the demulsification of PEs. Moreover, the cloud point of polyoxyethylene ether is the temperature for the complete separation of two phases. In this PTC system, the conversion rate for the esterification can reach to 92 % and the aqueous phase can be reused at least 5 times without sacrifice of the catalytic activity, demonstrating the potential application in industry.
Recyclable DMAP-Functionalized polymeric nanoreactors for highly efficient acylation of alcohols in aqueous systems
Qiu, Jiaqi,Meng, Fuliang,Wang, Maolin,Huang, Jinjin,Wang, Chengzhan,Li, Xiao,Yang, Guang,Hua, Zan,Chen, Tao
, (2021/03/30)
Fabrication of highly efficient and recyclable nanoreactors via macromolecular self-assembly represents a promising strategy for green organic transformation. In this study, small-molecule catalysts 4-(N,N-dimethylamino)pyridine (DMAP) functionalized nanoreactors were constructed by self-assembly of amphiphilic block copolymers with DMAP moieties in the hydrophobic block, leading to heterogeneous catalysts with excellent dispersity in water. The key preparation route included reversible addition-fragmentation chain transfer (RAFT) polymerization of 2-(N-methyl-N-(4-pyridyl)amino)ethyl methacrylate (MAPMA) and methyl methacrylate (MMA) using poly (oligomeric (ethylene glycol) methyl ether methacrylate) (POEGMA) as a hydrophilic macromoleculer RAFT reagent. The characterization by dynamic light scattering (DLS) and transmission electron microscopy (TEM) shows that the nanoreactors possess a core-shell nanostructure with the diameter of around 110 nm. The resulting polymeric nanoreactors showed excellent catalytic activity for acylation of alcohols in water. High conversion of a variety of alcohol (>99%) and excellent product selectivity were achieved. The high catalytic efficiency of the nanoreactors may be attributed to the enhancement of the interaction between the reactant and the catalyst in the confined hydrophobic space, which simulates how enzymes usually work. Moreover, the catalyst could be easily recovered by thermos-responsive separation and reused with high activity for more than 5 cycles. This study presents an efficient approach to achieve green catalytic reactions which are normally incompatible to aqueous conditions, potentially applicable to other catalytic systems such as metal-mediated organic transformations.
Zr-MOF-808 as Catalyst for Amide Esterification
Villoria-del-álamo, Beatriz,Rojas-Buzo, Sergio,García-García, Pilar,Corma, Avelino
supporting information, p. 4588 - 4598 (2020/12/25)
In this work, zirconium-based metal–organic framework Zr-MOF-808-P has been found to be an efficient and versatile catalyst for amide esterification. Comparing with previously reported homogeneous and heterogeneous catalysts, Zr-MOF-808-P can promote the reaction for a wide range of primary, secondary and tertiary amides with n-butanol as nucleophilic agent. Different alcohols have been employed in amide esterification with quantitative yields. Moreover, the catalyst acts as a heterogeneous catalyst and could be reused for at least five consecutive cycles. The amide esterification mechanism has been studied on the Zr-MOF-808 at molecular level by in situ FTIR spectroscopic technique and kinetic study.
Metal-Free Direct Oxidation of Aldehydes to Esters Using TCCA
Gaspa, Silvia,Porcheddu, Andrea,De Luca, Lidia
supporting information, p. 3666 - 3669 (2015/08/18)
Aromatic and aliphatic aldehydes are simply converted into esters by an efficient oxidative esterification carried out under mild conditions. The aldehydes are converted in situ into their corresponding acyl chlorides, which are then reacted with primary and secondary aliphatic, benzylic, allylic, and propargylic alcohols and phenols. A variety of esters are obtained in high yields.
Solvent-free transesterification in a ball-mill over alumina surface
Chatterjee, Tanmay,Saha, Debasree,Ranu, Brindaban C.
experimental part, p. 4142 - 4144 (2012/08/28)
An efficient procedure for transesterification has been developed in a ball-mill in the absence of any solvent, acid/base or metal catalyst. A variety of methyl, ethyl, allyl esters have been transesterified to higher benzyl and other esters in high yields by this procedure.
Synthesis of calix[4]arene alkylamine derivatives as new phase-transfer catalysts for esterification reaction
Akceylan, Ezgi,Yilmaz, Mustafa
experimental part, p. 6240 - 6245 (2011/09/19)
This study reports the synthesis of calix[4]arene-based phase-transfer catalysts derived from the reaction of 5,17-di-tert-butyl-25,27,26,28- tetrahydroxycalix[4]arene with N-ethylpiperazine, diallylamine or 4-benzylpiperidine. The catalytic efficiency of
NEW OXIDATIVE ESTERIFICATION OF ALCOHOLS WITH ALDEHYDES BY THE Br2-HMPT-NaHCO3.
Al Neirabeyeh, Mamdouh,Pujol, M. Dolors
, p. 2273 - 2276 (2007/10/02)
A new aldehyde-mediated oxidative esterification using a bromine/HMPT complex in the presence of sodium hydrogen carbonate is described.
Nitrobenzyl esters as potential conjugated alkylating and differentiation promoting agents: Antitumor effect in vivo
Wakselman,Cerutti,Chany
, p. 519 - 526 (2007/10/02)
A series of ortho and para-nitrobenzyl esters of short chain fatty acids (C2 to C5) and of the lipophilic aminoacid, L-valine, and some other o-nitrobenzylated products were prepared. Bioreductive or hydrolytic cleavages of these compounds could release both differentiation promoting agents such as butyric acid and electrophilic moieties able to alkylate DNA. The antitumor effects of these compounds, either alone and/or associated with an immunostimulating agent (corynebacterium parvum, CP) or interferon (IFN) treatment, was studied using the 180 TG Crocker Sarcoma grafted onto Swiss mice. Based on the mean survival time and the final survival rate, the most active compounds used alone were the o-nitrobenzyl acetate and the 0-nitrobenzyl butyrate. Previous stimulation of the immune competent cells by CP before antitumor treatment increased the efficiency of most of the nitrobenzylated derivatives studied. The association with IFN did not significantly improve the antitumor effect.
