Al(OTf)3 — A highly efficient catalyst for the tetrahydropyranylation of alcohols under solvent-free conditions

2008 ◽  
Vol 86 (12) ◽  
pp. 1099-1104 ◽  
Author(s):  
Ahmed Kamal ◽  
M Naseer A Khan ◽  
Y VV Srikanth ◽  
K Srinivasa Reddy
Keyword(s):  
Comparative Study ◽  
Efficient Method ◽  
Catalytic Amount ◽  
Solvent Free ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Efficient Catalyst ◽  
Highly Efficient ◽  
Solvent Free Conditions ◽  
The Comparative Study

A simple and highly efficient method has been developed for the tetrahydropyranylation of alcohols by their reaction with 3,4-dihydro-2H-pyran (DHP) using a catalytic amount (0.01–1 mol%) of aluminium triflate under solvent-free conditions. The effect of various factors like temperature, amount of the catalyst, and molar ratio of substrates on the reaction conditions has also been studied. The comparative study of tetrahydropyranylation of benzyl alcohol using various catalysts including some reported ones shows the efficiency of this catalyst.Key words: tetrahydropyranylation, aluminium triflate, alcohols, catalysis.

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.

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.

scholarly journals “In Situ” Generated “HCl”: A Highly Efficient Catalyst for One-Pot Synthesis of 1H-Indazolo [1,2-b]phthalazine-1,6,11-triones and 1Hpyrazolo[1,2-b]phthalazine-5,10-diones under Solvent-Free Conditions

2017 ◽  
Vol 58 (2) ◽  
Author(s):  
Behrooz Maleki ◽  
Samaneh Sedigh Ashrafi
Keyword(s):  
Phthalic Anhydride ◽  
Solvent Free ◽  
Synthetic Route ◽  
Reaction Conditions ◽  
One Pot ◽  
Efficient Catalyst ◽  
Highly Efficient ◽  
One Pot Synthesis ◽  
Solvent Free Conditions

<p>The rapid and environmental synthetic route to produce 1<em>H</em>-indazolo[1,2-b] phthalazine-1,6,11-triones and 1<em>H</em>-pyrazolo[1,2-b]phthalazine-5,10-diones derivatives have been developed <em>via</em> multicomponent and one-pot reactions of various aldehydes, cyclic or acyclic 1,3-diketones with: <em>i)</em> phthalhydrazide or <em>ii)</em> phthalic anhydride-hydrazinium hydroxide using wet 2,4,6-trichlorotriazine (TCT) as catalyst under solvent-free conditions. Simple and mild reaction conditions, the use of a cheap catalyst and easy workup and isolation are notable features of this method.</p>

BINAP-copper supported by hydrotalcite as an efficient catalyst for the borrowing hydrogen reaction and dehydrogenation cyclization under water or solvent-free conditions

2018 ◽  
Vol 20 (11) ◽  
pp. 2571-2577 ◽  
Author(s):  
Zhaojun Xu ◽  
Xiaoli Yu ◽  
Xinxin Sang ◽  
Dawei Wang
Keyword(s):  
Solvent Free ◽  
Efficient Catalyst ◽  
Highly Efficient ◽  
Solvent Free Conditions ◽  
Borrowing Hydrogen

A BINAP-Cu system supported by hydrotalcite has been developed and proved to be a highly efficient catalyst for the atom-efficient and green borrowing hydrogen reaction and dehydrogenative cyclization.

Rapid synthesis of homoallylic alcohol from aldehyde with allyltributylstannane under solvent-free conditions

2012 ◽  
Vol 90 (2) ◽  
pp. 167-172 ◽  
Author(s):  
Pranjal P. Bora ◽  
H. Atoholi Sema ◽  
Barisha Wahlang ◽  
Ghanashyam Bez
Keyword(s):  
Reaction Time ◽  
Phosphotungstic Acid ◽  
Catalytic Amount ◽  
Solvent Free ◽  
Reaction Conditions ◽  
Rapid Synthesis ◽  
Short Reaction Time ◽  
Solvent Free Conditions ◽  
Solvent Free Reaction

A catalytic amount (2 mol %) of phosphotungstic acid (PTA) is sufficient to synthesize homoallylic alcohol in excellent yields from aldehyde with allyltributylstannane upon grinding under solvent-free reaction conditions. Easy handling, very short reaction time, solvent-free reaction conditions, and aqueous workup free isolation protocol may make our method very useful for synthetic chemists.

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