N-Arylprolinamide as an organocatalyst for the direct asymmetric aldol reaction of acetone with isatin

Prolinamide‐Catalysed Asymmetric Organic Transformations

“…Yadav and Singh synthesised N ‐aryl‐ L ‐prolinamides (Scheme ) and evaluated their catalytic activity in enantioselective aldol reaction of isatin and acetone. The catalyst 154 was found to be better catalyst compared to the other catalyst at room temperature.…”

“…Silica supported prolinamide was also found to be better in term of enantioselectivities which is higher than that of the parent homogeneous catalyst and the catalyst can be recovered and recycled for this reaction. [85] The catalytic activity of carbohydrate-derived prolinamides (118)(119)(120)(121) in the direct asymmetric aldol reaction was described by Zhang and co-workers. The organocatalyst 119 b was found to better catalyst in aldol reaction of 4-nitrobenzaldehyde and cyclohexanone gave corresponding anti aldol product in high yield and excellent diastereoselectivity with 92% ee.…”

“…These organocatalysts also applicable for a variety of isatin derivatives and acetone to afforded corresponding aldol product in high yield and good enantioselectivity (Scheme 69). [60] Yadav and Singh synthesised N-aryl-L-prolinamides (Scheme 70) [119] and evaluated their catalytic activity in enantioselective aldol reaction of isatin and acetone. The catalyst 154 was found to be better catalyst compared to the other catalyst at room temperature.…”

“…Yadav and Singh also developed the direct asymmetric aldol reaction of isatins with acetone catalyzed by prolinamide (2 S,4R)-4-hydroxy-N-((S)-1 phenylethyl)pyrrolidine-2-carboxamide (93) (10 mol %) at -35°C in THF and afforded the product in 79% yield with 74% ee (Scheme 71). [120] A hydroxyl group on the prolinamide enhanced the reactivity of the organocatalyst.…”

Synthesis of New Di- and Triamides as Potential Organocatalysts for Asymmetric Aldol Reaction in Water

“…8 To overcome these drawbacks, some derivatives of proline had been succesfully synthesized and used in asymmetric aldol reaction and new modifications on proline are still under investigation. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] Especially, proline based amides have been used succesfully for this reaction. [25][26][27][28][29][30] These derivatives have some advantages such as easy preperation, high stability and the presence of important functional groups.…”