scholarly journals Chemoselective Preparation of 1,1-Diacetates from Aldehydes, Mediated by a Keggin Heteropolyacid Under Solvent Free Conditions at Room Temperature

2007 ◽  
Vol 4 (1) ◽  
pp. 83-89 ◽  
Author(s):  
G. Romanelli ◽  
P. Dimitroff ◽  
P. Vázquez ◽  
J. C. Autino
Keyword(s):  
Acetic Anhydride ◽  
Efficient Method ◽  
Room Temperature ◽  
Catalytic Amount ◽  
Solvent Free ◽  
Solvent Free Conditions

A simple, general and efficient method has been developed for the conversion of aldehydes to 1,1-diacetates using acetic anhydride, a catalytic amount of non commercial Keggin heteropolyacid (H6PalMo11O40) (1% mol) in solvent free conditions at room temperature. Aromatic and aliphatic, simple and conjugated aldehydes were protected with excellent yields.

Iron (III) chloride hexahydrate as a highly efficient catalyst for acetylation of protic nucleophiles with acetic anhydride under solvent-free conditions

2020 ◽  
Vol 07 ◽  
Author(s):  
Naoures Jamel Eddine ◽  
Fayçal Jennen ◽  
Yakdhane Kacem ◽  
Jamil Kraiem
Keyword(s):  
Acetic Anhydride ◽  
Room Temperature ◽  
Catalytic Amount ◽  
Solvent Free ◽  
Environmentally Benign ◽  
Efficient Catalyst ◽  
Highly Efficient ◽  
Solvent Free Conditions ◽  
Chloride Hexahydrate ◽  
New Methodologies

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.

A multicomponent reaction on a ‘free’ KCC-1 catalyst at room temperature under solvent free conditions by visible light

RSC Advances ◽  
2016 ◽  
Vol 6 (59) ◽  
pp. 54236-54240 ◽  
Author(s):  
Seyed Mohsen Sadeghzadeh
Keyword(s):  
Visible Light ◽  
Multicomponent Reaction ◽  
Efficient Method ◽  
Room Temperature ◽  
Solvent Free ◽  
Green Protocol ◽  
Mild Conditions ◽  
Solvent Free Conditions

A green and efficient method for the synthesis of various triazolo[1,2-a]indazoletrione under mild conditions is reported, that making it a genuinely green protocol.

An efficient method for the silylation of hydroxyl groups with hexamethyldisilazane (HMDS) catalyzed by aluminum tris(dihydrogen phosphate) under solvent-free and ambient conditions

2008 ◽  
Vol 86 (8) ◽  
pp. 841-845 ◽  
Author(s):  
Hamid Reza Shaterian ◽  
Majid Ghashang ◽  
Nassrin Tajbakhsh Riki ◽  
Manijeh Asadi
Keyword(s):  
Heterogeneous Catalyst ◽  
Efficient Method ◽  
Room Temperature ◽  
Solvent Free ◽  
Dihydrogen Phosphate ◽  
Hydroxyl Groups ◽  
Ambient Conditions ◽  
Solvent Free Conditions ◽  
Free Hydroxyl ◽  
Recyclable Heterogeneous Catalyst

A highly efficient and mild procedure for the trimethylsilylation of a wide variety of alcohols, including primary, benzylic, secondary, hindered secondary, tertiary, phenols, and oximes with hexamethyldisilazane (HMDS), using Al(H2PO4)3 as a recyclable heterogeneous catalyst at room temperature in a few minutes with excellent yields under solvent-free conditions is described.Key words: trimethylsilylation, hexamethyldisilazane, aluminum tris(dihydrogen phosphate) [Al(H2PO4)3], solvent-free, hydroxyl groups.

scholarly journals LiHSO4/SiO2as a New, Efficient and Reusable Catalytic System for the Chemoselective Conversion of Aldehydes to Acylals under Solvent-Free Conditions

2009 ◽  
Vol 6 (s1) ◽  
pp. S390-S396 ◽  
Author(s):  
Abdolkarim Zare ◽  
Alireza Hasaninejad ◽  
Esmael Rostami ◽  
Ahmad Reza Moosavi-Zare ◽  
Maria Merajoddin ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Acetic Anhydride ◽  
Catalytic System ◽  
Catalytic Amount ◽  
Significant Loss ◽  
Solvent Free ◽  
Reaction Conditions ◽  
Highly Efficient ◽  
Solvent Free Conditions

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.

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
Keyword(s):  
Nmr Spectroscopy ◽  
Acetic Anhydride ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Room Temperature ◽  
Solvent Free ◽  
Highly Efficient ◽  
Solvent Free Conditions ◽  
Cellulose Acetates

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.

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