65962-16-5Relevant academic research and scientific papers
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.
Silica triflate as an efficient reagent for the chemoselective formylation of alcohols
Shirini, Farhad,Marjani, Katayoun,Nahzomi, Hossein Taherpour,Zolfigol, Mohammad Ali
, p. 1245 - 1251 (2008/02/05)
Silica triflate, as a new and stable silica-based reagent, is prepared by a reaction of silica gel with trifluoromethane sulfonyl chloride at room temperature. This reagent can be used for the efficient and selective formylation of alcohols in the presence of phenols in a relatively short reaction time and high yields under heterogeneous reaction conditions.
Cerium polyoxometalate as a reusable catalyst for acetylation and formylation of alcohols
Mirkhani, Valiollah,Tangestaninejad, Shahram,Moghadam, Majid,Yadollahi, Bahram,Alipanah, Ladan
, p. 1257 - 1263 (2007/10/03)
Efficient esterification of primary and sterically-hindered secondary or tertiary alcohols with acetic anhydride was achieved in the presence of ammonium decatungestocerate(IV) icosahydrate, (NH4)8[CeW 10O36]·OH2O, as catalyst in high yields. Primary and secondary alcohols were also converted to their corresponding acetates and formates with acetic acid and ethyl formate in the presence of this catalyst. Easy work-up, non-toxicity, reusability, and stability of the catalyst are noteworthy advantages of this method. Springer-Verlag 2004.
Novel catalytic acetylation and formylation of alcohols with potassium dodecatungstocobaltate trihydrate (K5CoW12O40·3H2O)
Habibi, Mohammad H,Tangestaninejad, Shahram,Mirkhani, Valiollah,Yadollahi, Bahram
, p. 8333 - 8337 (2007/10/03)
Acetylation and formylation reactions of alcohols with ethyl acetate, acetic acid and ethyl formate were catalyzed with potassium dodecatungstocobaltate trihydrate (K5CoW12O40·3H2O) in a mild, efficient and convenient method with high to excellent yields.
A convenient and chemoselective acetylation and formylation of alcohols and phenols using acetic acid and ethyl formate in the presence of Bi(III) salts
Mohammadpoor-Baltork,Khosropour,Aliyan
, p. 280 - 282 (2007/10/03)
A variety of alcohols are acetylated and formylated efficiently with acetic acid and ethyl formate in the presence of catalytic amounts of Bi(III) salts such as BiCl3, Bi(TFA)3 and Bi(OTf)3. BiCl3 and Bi(OTf)3 are also effective catalysts for acetylation of phenols. All of these catalysts are ineffective in formylation of phenols. Selective acetylation and formylation of alcohols in the presence of phenols is an additional advantage of this procedure.
