Inhibition of enantioselective hydrogenation of ethyl acetoacetate

1983 ◽  
Vol 32 (4) ◽  
pp. 689-692 ◽  
Author(s):  
V. V. Chernysheva ◽  
I. P. Murina ◽  
E. I. Klabunovskii
Keyword(s):  
Ethyl Acetoacetate ◽  
Enantioselective Hydrogenation

Enantioselective hydrogenation of ethyl acetoacetate on asymmetric Raney Ni catalysts

1987 ◽  
Vol 36 (3) ◽  
pp. 476-478 ◽  
Author(s):  
N. D. Zubareva ◽  
V. V. Chernysheva ◽  
Yu. A. Grigor'ev ◽  
E. I. Klabunovskii
Keyword(s):  
Ethyl Acetoacetate ◽  
Enantioselective Hydrogenation ◽  
Ni Catalysts ◽  
Raney Ni

On the enantioselective hydrogenation of ethyl acetoacetate on a skeletal copper catalyst modified with amino acids

1977 ◽  
Vol 26 (10) ◽  
pp. 2218-2218
Author(s):  
A. A. Vedenyapin ◽  
Yu. S. Airapetov ◽  
E. I. Klabunovskii ◽  
Ya. D. Fridman ◽  
L. Ya. Mikhailyuk
Keyword(s):  
Amino Acids ◽  
Ethyl Acetoacetate ◽  
Copper Catalyst ◽  
Enantioselective Hydrogenation ◽  
Skeletal Copper

ChemInform Abstract: Enantioselective Hydrogenation of Ethyl Acetoacetate on Dissymmetric Raney-Nickel Catalysts.

ChemInform ◽  
1987 ◽  
Vol 18 (42) ◽  
Author(s):  
N. D. ZUBAREVA ◽  
V. V. CHERNYSHEVA ◽  
YU. A. GRIGOR'EV ◽  
E. I. KLABUNOVSKII
Keyword(s):  
Raney Nickel ◽  
Ethyl Acetoacetate ◽  
Enantioselective Hydrogenation ◽  
Nickel Catalysts

Synthesis of Dihydropyrimidinones (DHPMs) and Hexahydro Xanthene Catalyzed by 1,4-Diazabicyclo [2.2.2] Octane Triflate Under Solvent-Free Condition

2019 ◽  
Vol 16 (5) ◽  
pp. 776-786 ◽  
Author(s):  
Deepa ◽  
Geeta D. Yadav ◽  
Mohd J. Aalam ◽  
Pooja Chaudhary ◽  
Surendra Singh
Keyword(s):  
Ethyl Acetoacetate ◽  
Biginelli Reaction ◽  
Solvent Free ◽  
Efficient Catalyst ◽  
Solvent Free Condition ◽  
Solvent Free Conditions ◽  
Xanthene Derivatives ◽  
Different Temperatures ◽  
Flash Column Chromatography ◽  
Biginelli Condensation

Objective:DABCO salts were evaluated as catalysts for the Biginelli reaction between 4- methoxybenzaldehyde, urea and ethyl acetoacetate under solvent-free conditions. 1,4-Diazabicyclo [2.2.2] octane triflate was found to be a simple, inexpensive, highly efficient catalyst for Biginelli reaction for a variety aromatic aldehyde with urea and ethyl acetoacetate at 80°C afforded corresponding 3,4-dihydropyrimidinones in 50-99% yields after 30-120 minutes. 1,3-Cyclohexadione was used in place of ethyl acetoacetate in the absence of urea this methodology is giving hexahydro xanthene derivatives in good to excellent yields after 3-4 hours.Methods:DABCO salt 4 (5 mol%), 4-methoxybenzaldehyde (0.73 mmol) and urea (0.73 mmol) were stirred for 10 minutes at 80°C, then ethyl acetoacetate (1.5 equiv.) was added and reaction mixture was stirred at 80°C for specified time. The resulting solution was stirred continuously and progress of the reaction was followed by TLC. The crude reaction mixture was purified by flash column chromatography on silica gel (hexane/ethyl acetate (1:2)) to give pure desired product.Results:Reaction conditions of the Biginelli reaction were optimized using 4-methoxybenzaldehyde (0.73 mmol), urea (0.73 mmol), and ethyl acetoacetate (5 equiv.) as model substrates catalyzed by 1,4-Diazabicyclo [2.2.2] octane triflate (5 mol%) in a different solvents, screening of different catalysts and different temperatures. Neat condition was found to be the best for the Biginelli condensation and corresponding 3,4- dihydropyrimidinones was obtained in good to excellent yields. When the reaction was carried out with benzaldehyde derivatives and cyclohexane-1,3-dione in place of ethyl acetoacetate in the absence of urea, solely corresponding hexahydro xanthene derivatives were obtained in 61-91% yields.Conclusion:In conclusion, we have applied salts of 1,4-Diaza-bicyclo [2.2.2] octane as catalysts in the Biginelli condensation and corresponding 3,4-dihydropyrimidinones were obtained in 50- 99% yields under solvent free conditions. This methodology is having advantages like simple work-up; low loading of catalyst and reaction was performed at moderate temperature under solvent-free conditions.

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