An ionic liquid influenced l-proline catalysed asymmetric Michael addition of ketones to nitrostyrene

L-Proline as an efficient and reusable promoter for the synthesis of coumarins in ionic liquid

“…L-Proline in combination with ionic liquids has proved to be an efficient system for Knoevenagel condensation (Wang et al, 2006), direct asymmetric aldol reactions (Loh et al, 2002;Kotrusz et al, 2002;Gruttadauria et al, 2004;Salaheldin et al, 2004), cross-aldol reactions (Córdova, 2004), Michael additions (Kitazume et al, 2003;Hagiwara et al, 2004;Kotrusz et al, 2004;Rasalkar et al, 2005), α-aminations of aldehydes and ketones (Kotrusz et al, 2005), Ullmanntype reactions , as well as Mannich reactions (Chowdari et al, 2003). To the best of our knowledge, there is no attempt of the use of L-proline as a promoter in ionic liquid for the synthesis of coumarins.…”

Enantioselective and diastereoselective Michael addition of ketone/aldehyde to trans‐nitroolefins catalyzed by a novel chiral pyrrolidine‐thiourea

“…Salunkhe improved the selectivity of this reaction by using ionic liquids as the reaction media, but only moderate selectivity could be obtained. 3 Oriyama demonstrated that (S)-homoproline, which possesses a methylene spacer between the pyrrolidine ring and the carboxyl group, is a better catalyst for the asymmetric Michael addition of ketones to nitroolefins than (S)-proline itself. 4 Also, asymmetric Michael addition of unmodified aldehydes as donors to nitroolefins has been developed by using (S)-proline-derived diamine such as (S)-2-(morpholinomethyl)-pyrrolidine and (S)-1-(2-pyrrolidinylmethyl) pyrrolidine as the catalysts, as shown by Barbas III.…”

Ionic Liquids Recycling for Reuse

“…11.c is directly applicable. Rasalkar et al (2005) extracted the system of IL and l-proline with diethyl ether to remove all organic impurities and recharged it with a new batch of substrates. The IL acted as a reservoir for the catalyst.…”