Influence of ionic liquids on the phase transfer-catalysed enantioselective Michael reaction

Enantioselective Organocatalysis in Ionic Liquids: Addition of Aliphatic Aldehydes and Ketones to Diethyl Azodicarboxylate

“…[19][20][21][22][23][24][25] In organocatalysis, ionic liquids have been used for the quinidinium bromide catalyzed Michael addition of dimethyl malonate to chalcone. [26] Recently, we [27] and (independently) Loh et al [28] found that ionic liquids are excellent solvents for l-proline-catalyzed aldol reactions. In addition, we have demonstrated that the combination of l-proline and an ionic liquid also represents an excellent medium for the enantioselective Michael addition of aldehydes and ketones to β-nitrostyrenes.…”

Solvent‐Induced Reversal of Enantioselectivity in the Synthesis of Succinimides by the Addition of Aldehydes to Maleimides Catalysed by Carbamate‐Monoprotected 1,2‐Diamines

“…Thus, an inversion of the enantioselectivity was discovered in the enantioselective Michael addition of dimethyl malonate to chalcone organocatalyzed by a quininium ammonium salt, when changing the reaction medium from conventional organic solvents to ionic liquids. [7] In addition, a solvent-dependent enantioinduction reversal was observed when using the imidazolidinone salt 1 as organocatalyst in the Michael addition of an indol to acroleine for the synthesis of a pyrroloindoline. [8] Later, α,α-phenylprolinol silyl ether 2 was shown to organocatalyze the enantioselective α-phenylselenenylation of isovaleraldehyde, revealing a change in the sense of the enantioselectivity when changing the polarity of the solvent.…”

Michael Additions of Methylene Active Compounds to Chalcone in Ionic Liquids without any Catalyst: The Peculiar Properties of Ionic Liquids

“…[21][22][23][24][25][26][27][28] Dell'Anna found that [bmim]BF 4 is a good solvent for the addition of acetylacetone to methyl vinyl ketone when NiA C H T U N G T R E N N U N G (acac) 2 is used as the catalyst. [29] Yadav described [bmim]BF 4 as an excellent solvent for the Michael additions of b-ketoesters to methylvinyl ketone, cyclohexenone and cyclopentenone when copper(ii) triflate was used as the catalyst.…”