ChemInform Abstract: Pyrrolidine-Pyridine Base Catalysts for the Enantioselective Michael Addition of Ketones to Chalcones.

ChemInform ◽  
2010 ◽  
Vol 41 (10) ◽  
Author(s):  
Da-Zhen Xu ◽  
Sen Shi ◽  
Yingjun Liu ◽  
Yongmei Wang
Keyword(s):  
Michael Addition ◽  
Pyridine Base ◽  
Base Catalysts

Pyrrolidine–pyridine base catalysts for the enantioselective Michael addition of ketones to chalcones

Tetrahedron ◽  
2009 ◽  
Vol 65 (45) ◽  
pp. 9344-9349 ◽  
Author(s):  
Da-Zhen Xu ◽  
Sen Shi ◽  
Yingjun Liu ◽  
Yongmei Wang
Keyword(s):  
Michael Addition ◽  
Pyridine Base ◽  
Base Catalysts

scholarly journals Recoverable Phospha-Michael Additions Catalyzed by a 4-N,N-Dimethylaminopyridinium Saccharinate Salt or a Fluorous Long-Chained Pyridine: Two Types of Reusable Base Catalysts

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1159
Author(s):  
Eskedar Tessema ◽  
Vijayanath Elakkat ◽  
Chiao-Fan Chiu ◽  
Jing-Hung Zheng ◽  
Ka Long Chan ◽  
...  
Keyword(s):  
Michael Addition ◽  
Polar Solvent ◽  
Addition Reaction ◽  
High Yield ◽  
Addition Reactions ◽  
Polar Solvents ◽  
Unsaturated Bond ◽  
Base Catalysts ◽  
Michael Additions

Phospha-Michael addition, which is the addition reaction of a phosphorus-based nucleophile to an acceptor-substituted unsaturated bond, certainly represents one of the most versatile and powerful tools for the formation of P-C bonds, since many different electrophiles and P nucleophiles can be combined with each other. This offers the possibility to access many diversely functionalized products. In this work, two kinds of basic pyridine-based organo-catalysts were used to efficiently catalyze phospha-Michael addition reactions, the 4-N,N-dimethylaminopyridinium saccharinate (DMAP·Hsac) salt and a fluorous long-chained pyridine (4-Rf-CH2OCH2-py, where Rf = C11F23). These catalysts have been synthesized and characterized by Lu’s group. The phospha-Michael addition of diisopropyl, dimethyl or triethyl phosphites to α, β-unsaturated malonates in the presence of those catalysts showed very good reactivity with high yield at 80–100 °C in 1–4.5 h with high catalytic recovery and reusability. With regard to significant catalytic recovery, sometimes more than eight cycles were observed for DMAP·Hsac adduct by using non-polar solvents (e.g., ether) to precipitate out the catalyst. In the case of the fluorous long-chained pyridine, the thermomorphic method was used to efficiently recover the catalyst for eight cycles in all the reactions. Thus, the easy separation of the catalysts from the products revealed the outstanding efficacy of our systems. To our knowledge, these are good examples of the application of recoverable organo-catalysts to the DMAP·Hsac adduct by using non-polar solvent and a fluorous long-chained pyridine under the thermomorphic mode in phospha-Michael addition reactions.

Michael addition of methyl crotonate over solid base catalysts

1997 ◽  
Vol 165 (1-2) ◽  
pp. 319-325 ◽  
Author(s):  
Hajime Kabashima ◽  
Hideto Tsuji ◽  
Hideshi Hattori
Keyword(s):  
Michael Addition ◽  
Solid Base ◽  
Solid Base Catalysts ◽  
Base Catalysts

Michael addition of nitromethane to α,β-unsaturated carbonyl compounds over solid base catalysts

2000 ◽  
Vol 155 (1-2) ◽  
pp. 23-29 ◽  
Author(s):  
Hajime Kabashima ◽  
Hideto Tsuji ◽  
Tadashi Shibuya ◽  
Hideshi Hattori
Keyword(s):  
Michael Addition ◽  
Carbonyl Compounds ◽  
Solid Base ◽  
Solid Base Catalysts ◽  
Base Catalysts

Fatty acid ketodienes and fatty acid ketotrienes: Michael addition acceptors that accumulate in wounded and diseased Arabidopsis leaves

2000 ◽  
Vol 24 (4) ◽  
pp. 467-476 ◽  
Author(s):  
Sabine Vollenweider ◽  
Hans Weber ◽  
Stephanie Stolz ◽  
Aurore Chetelat ◽  
Edward E. Farmer
Keyword(s):  
Fatty Acid ◽  
Michael Addition

Ligand-Enabled γ-C(sp3)–H Olefination of Free Carboxylic Acids

2020 ◽  
Author(s):  
Kiron Kumar Ghosh ◽  
Alexander Uttry ◽  
Francesca Ghiringhelli ◽  
Arup Mondal ◽  
Manuel van Gemmeren
Keyword(s):  
Reaction Mechanism ◽  
Carboxylic Acids ◽  
Michael Addition ◽  
Kinetic Studies ◽  
Wide Range ◽  
Palladium Catalyzed

We report the ligand enabled C(sp3)–H activation/olefination of free carboxylic acids in the γ-position. Through an intramolecular Michael-addition, δ-lactones are obtained as products. Two distinct ligand classes are identified that enable the challenging palladium-catalyzed activation of free carboxylic acids in the γ-position. The developed protocol features a wide range of acid substrates and olefin reaction partners and is shown to be applicable on a preparatively useful scale. Insights into the underlying reaction mechanism obtained through kinetic studies are reported.<br>

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