scholarly journals Silica: An efficient catalyst for one-pot regioselective synthesis of dithioethers

2014 ◽  
Vol 10 ◽  
pp. 26-33 ◽  
Author(s):  
Samir Kundu ◽  
Babli Roy ◽  
Basudeb Basu

The development of a silica-promoted highly selective synthesis of 1,2 or 1,3-dithioethers via solvent-free one-pot tandem reactions of an allyl bromide with excess thiol at room temperature is described. The choice of silica gel, either pre-calcined or moistened with water, exhibited notable regioselectivity in the formation of dithioethers. Plausible mechanistic routes were explored and postulated.

2017 ◽  
Vol 25 (2) ◽  
pp. 163-178 ◽  
Author(s):  
Reza Heydari ◽  
Rohollah Rahimi ◽  
Mehrnoosh Kangani ◽  
Afshin Yazdani-Elah-Abadi ◽  
Mojtaba Lashkari

Abstract The potassium carbonate was applied as a green and efficient catalyst for the one-pot synthesis of pyran annulated heterocyclic systems, via the condensation between aromatic aldehydes, malononitrile and dimedone/1-naphtole by a grinding method at room temperature and solvent-free conditions. Short reaction times, environmentally friendly procedure and excellent yields are the main advantages of this procedure which makes it more economic than other environmentally synthetic methods.


2018 ◽  
Vol 21 (4) ◽  
pp. 254-261 ◽  
Author(s):  
Amit S. Waghmare ◽  
Shivaji S. Pandit ◽  
Dayanand M. Suryawanshi

Aim and Objective: The present method is simple, green and highly efficient for the synthesis of 2-amino-4H-pyran derivatives which are achieved by a one pot three component cyclocondensation of aldehyde, malanonitrile and ethyl acetoacetate or methyl acetoacetate using DABCO under solvent free with grinding conditions at room temperature. Material and Methods: Some of the synthesized compounds were screened for their antimicrobial and antifungal activity. The study shows that these compounds show good antimicrobial activity. Furthermore, eight of the synthesized compounds were selected for screening of their anticancer activity against human astrocytoma-glioblastoma cell line (U373MG). Some of the compounds show good anticancer activity. Result: Grinding synthesis of 2-amino-4H-pyran derivatives catalyzed by DABCO with various aromatic aldehydes under solvent-free conditions at room temperature was examined. The obtained compounds (22 entries) were well synthesized in good to excellent yields. Conclusion: The present method is simple, rapid, and most efficient green protocol for the synthesis of 2-amino-4H-pyran derivatives using highly inexpensive and easily available DABCO as an efficient catalyst under grinding and solvent free condition at room temperature.


2018 ◽  
Vol 21 (8) ◽  
pp. 602-608 ◽  
Author(s):  
Zainab Ehsani-Nasab ◽  
Ali Ezabadi

Aim and Objective: In the present work, 1, 1’-sulfinyldiethylammonium bis (hydrogen sulfate) as a novel room temperature dicationic ionic liquid was synthesized and used as a catalyst for xanthenediones synthesis. Material and Method: The dicationic ionic liquid has been synthesized using ethylamine and thionyl chloride as precursors. Then, by the reaction of [(EtNH2)2SO]Cl2 with H2SO4, [(EtNH2)2SO][HSO4]2 was prepared and after that, it was characterized by FT-IR, 1H NMR, 13C NMR as well as Hammett acidity function. This dicationic ionic liquid was used as a catalyst for the synthesis of xanthenediones via condensation of structurally diverse aldehydes and dimedone under solvent-free conditions. The progress of the reaction was monitored by thin layer chromatography (ethyl acetate/n-hexane = 3/7). Results: An efficient solvent-free method for the synthesis of xanthenediones has been developed in the presence of [(EtNH2)2SO][HSO4]2 as a powerful catalyst with high to excellent yields, and short reaction times. Additionally, recycling studies have demonstrated that the dicationic ionic liquid can be readily recovered and reused at least four times without significant loss of its catalytic activity. Conclusion: This new dicationic ionic liquid can act as a highly efficient catalyst for xanthenediones synthesis under solvent-free conditions.


1999 ◽  
Vol 23 (9) ◽  
pp. 574-575
Author(s):  
Firouz Matloubi Moghaddam ◽  
Mohammad Ghaffarzadeh ◽  
Seyed Hossein Abdi-Oskoui

An AICl3–ZnCl2 mixture supported on silica gel is found to be an efficient medium for the Fries rearrangement of acyloxybenzene or naphthalene derivatives in solvent-free conditions under microwave irradiation.


ChemInform ◽  
2010 ◽  
Vol 41 (44) ◽  
pp. no-no
Author(s):  
Gowravaram Sabitha ◽  
N. Mallikarjuna Reddy ◽  
M. Nagendra Prasad ◽  
G. S. K. Raja ◽  
J. S. Yadav

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rabindranath Singha ◽  
Aminul Islam ◽  
Pranab Ghosh

AbstractA convenient and efficient solvent-free, facile, one-pot three-component graphene oxide catalysed approach has been described for the synthesis of chromeno-[4,3-b]quinolin-6-one derivatives from 4-hydroxycoumarin with aldehydes and aromatic amines. Graphene oxide (GO) has proved to be a new class of heterogeneous carbocatalyst which could be easily recovered and reused up to 5th run without significant loss of its catalytic activity. A broad scope of substrate applicability is offered and a plausible mechanism is also suggested for this developed protocol.


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