Potassium Phosphate or Silica Sulfurc Acid Catalyzed Conjugate Addition of Thiols to α,β-Unsaturated Ketones at Room Temperature under Solvent-Free Conditions.

ChemInform ◽  
2007 ◽  
Vol 38 (14) ◽  
Author(s):  
D. M. Pore ◽  
M. S. Soudagar ◽  
U. V. Desai ◽  
T. S. Thopate ◽  
P. P. Wadagaonkar
2020 ◽  
Vol 50 (10) ◽  
pp. 1545-1560 ◽  
Author(s):  
Gurpreet Kaur ◽  
Mussarat Shamim ◽  
Vaishali Bhardwaj ◽  
Vivek Kumar Gupta ◽  
Bubun Banerjee

2021 ◽  
Vol 17 ◽  
pp. 2642-2649
Author(s):  
Akhil K Dubey ◽  
Raghunath Chowdhury

An enantioselective 1,4-conjugate addition of nitromethane to β-silyl α,β-unsaturated carbonyl compounds catalyzed by bifunctional squaramide catalysts has been developed. This methodology offers both enantiomers of β-silyl nitroalkanes in good to excellent yields (up to 92%) and enantioselectivities (up to 97.5% ee) under solvent-free conditions at room temperature. Control experiments reveal that the presence of a β-silyl group in the enones is crucial for high reactivity under the optimized reaction conditions.


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.


2006 ◽  
Vol 36 (16) ◽  
pp. 2363-2369 ◽  
Author(s):  
Liangce Rong ◽  
Xiaoyue Li ◽  
Haiying Wang ◽  
Daqing Shi ◽  
Shujiang Tu ◽  
...  

2005 ◽  
Vol 2005 (3) ◽  
pp. 171-172 ◽  
Author(s):  
Min Zhang ◽  
Yi-Qun Li

Aromatic aldehydes can be converted into the corresponding 1,1-diacetates rapidly in the presence of catalytic amounts of Ce(SO4)2·4H2O at room temperature in excellent yield under solvent-free conditions. The catalyst can easily be recovered and reused at least 4 times.


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