New Application of 1,4-Dihydropyridine System: Michael Reactions Mediated by 1,4-Dihydropyridine–Enolate Adduct in Micellar Medium
作者:Sabir H. Mashraqui、Madhavi A. Karnik
DOI:10.1246/cl.2003.1064
日期:2003.11
1,4-dihydropyridine-acetophenone enolate adduct, in catalytic amount effects Michael reactions in aqueous cationic micelles of cetyltrimethylammonium bromide. The enolate, generated by dissociation of the adduct abstracts a proton from readily enolizable substrates to bring about the Michael reaction under mild conditions in fair to good yields without side products.
Michael Additions of Methylene Active Compounds to Chalcone in Ionic Liquids without any Catalyst: The Peculiar Properties of Ionic Liquids
作者:Mária Mečiarová、Štefan Toma
DOI:10.1002/chem.200600870
日期:2007.1.22
Michael additions of malonodinitrile as well as several other reagents to chalcone have been found to proceed well in pure ionic liquids, without the addition of any catalyst. The catalytic effect of the residual acidity caused by hydrolysis of ionic liquids anions was excluded because HCl in dichloromethane did not catalyse the Michael addition of malonodinitrile. Piperidine was tested as the catalyst
The LBAs (Lewis acid-assisted Brønsted acidcatalysis) is proposed as possible mechanistic process in the simple FeCl3-catalyzed Michael reactions of chalcones with active methylene compounds in organic solvents. And iron salts were found to be effective promoters in the asymmetricMichaeladdition of 4-hydroxycoumarin to α,β-unsaturated ketone, which resulted in excellent yield and high level of enantioselectivity
Hypoiodite-catalysed oxidative cyclisation of Michael adducts of chalcones with 1,3-dicarbonyl compounds: a facile and versatile approach to substituted furans and cyclopropanes
Through hypoiodite catalysis, the oxidative cyclisation of Michael adducts of chalcones with 1,3-dicarbonyl compounds for divergent synthesis of either furans or cyclopropanes is developed. The selective synthesis of major products...