A highly efficient, solvent-free and energy-effective method of cellulose acetylation

e-Polymers ◽  
2005 ◽  
Vol 5 (1) ◽  
Author(s):  
Abdelmajid Memmi ◽  
Robert Granet ◽  
Yves Champavier ◽  
Pierre Krausz

AbstractAcetylation of cellulose by acetic anhydride was found to be catalysed quantitatively by iodine under solvent-free conditions at room temperature. Cellulose acetates were characterised by 1H NMR spectroscopy.

2020 ◽  
Vol 07 ◽  
Author(s):  
Naoures Jamel Eddine ◽  
Fayçal Jennen ◽  
Yakdhane Kacem ◽  
Jamil Kraiem

Background: Acetylation of protic nucleophiles is used to protect these functional groups. Most of the methods described in the literature use solvents, one equivalent or more of toxic bases or expensive and toxic catalysts. Therefore, new methodologies are still in demand, above all, greener and more economical procedures. Objective: An eco-efficient method developed for acetylation of alcohols, phenols, thiols, amines and carbohydrates, using acetic anhydride and a catalytic amount of the environmentally benign and inexpensive FeCl3.6H2O under solvent free conditions. Methods: Acetylation of a variety of protic nucleophiles was performed using 0.2 mol % of FeCl3.6H2O as the catalyst, and 1.2 equiv. as the acetylating agent at room temperature and under solvent free conditions. Results: Our procedure appears to be highly efficient and promoted rapid and quantitative acetylation under simple and minimum manipulation. Chromatography or recrystallization were generally not necessary for the purification of products. Conclusion: This eco-friendly protocol appears to be potentially universally applicable in organic design to protect protic nucleophiles and potentially scalable for industrial fields.


2009 ◽  
Vol 6 (s1) ◽  
pp. S390-S396 ◽  
Author(s):  
Abdolkarim Zare ◽  
Alireza Hasaninejad ◽  
Esmael Rostami ◽  
Ahmad Reza Moosavi-Zare ◽  
Maria Merajoddin ◽  
...  

A highly efficient, green and expeditious solvent-free method is described for the chemoselective conversion of aldehydes to the corresponding acylals in excellent yields, using acetic anhydride in the presence of catalytic amount (20 mol%) of silica-supported LiHSO4. Ketones does not react under these reaction conditions. LiHSO4/SiO2can be recovered and reused without any significant loss of its catalytic activity.


RSC Advances ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 1128-1133
Author(s):  
Xiaoming Wang ◽  
Xin Xu

Molecular zinc dihydrides were found to be highly efficient catalysts for the hydroboration of nitriles and imines at room temperature under solvent-free conditions.


2005 ◽  
Vol 70 (4) ◽  
pp. 579-583 ◽  
Author(s):  
Davood Habibi ◽  
Omid Marvi

The syntheses of cis-3a,4,7,7a-tetrahydroisoindole-1,3-dione derivatives and some cyclic diimides were performed by the reaction of different aromatic and aliphatic amines and diamines with cis-1,2,3,6-tetrahydrophthalic anhydride and maleic anhydride on montmorillonite K-10 under microwave irradiation and solvent- free conditions. The desired attractive products were obtained in high yields and characterized by elemental analysis aswell as by IR and 1H-NMR spectroscopy.


2019 ◽  
Vol 16 (3) ◽  
pp. 449-457 ◽  
Author(s):  
Dong-Xiao Cui ◽  
Yue-Dan Li ◽  
Jun-Chao Zhu ◽  
Yan-Yan Jia ◽  
Ai-Dong Wen ◽  
...  

Aim and Objective: The direct β-functionalization of trans-β-nitroolefins by Michael reaction is regarded as an efficient way to provide precursors for β-functional amines. However, Michael additions by grinding means with solvent-free conditons are rarely reported. We have developed facile access to β-functional nitroalkanes by grinding means under solvent-free conditions. Materials and Methods: From commercially available materials including ethyl 2-nitroacetate, alkyl 2-cyanoacetates and malononitrile, the grinding reactions between these above-mentioned activated methylenecompounds and various trans-β-nitroolefins were performed at room temperature and solvent-free conditions. Results: A highly efficient direct Michael reaction of nitroolefins by simple grinding means has been developed. Various trans-nitrostyrenes were easily converted into corresponding β-functional nitroalkanes in excellent yields within 5~10 min (up to 36 examples). Conclusion: Herein, we have developed a simple and efficient way to β-functional nitroalkanes through Michael reactions by grinding means. The grinding Michael reaction is fast, clean and stable and these Michael adducts could be easily converted into the other amino compounds served as building blocks in organic synthesis.


2017 ◽  
Vol 13 ◽  
pp. 1977-1981 ◽  
Author(s):  
Hashem Sharghi ◽  
Mahdi Aberi ◽  
Mohsen Khataminejad ◽  
Pezhman Shiri

A highly efficient, simple and environmentally friendly synthesis of 3-arylquinolines has been developed in the presence of Al2O3/MeSO3H via one-pot reaction of anilines and styrene oxide. This methodology provides very rapid access to 3-arylquinolines in good to excellent yields under solvent-free conditions at room temperature in air.


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