149673-13-2Relevant articles and documents
Synthesis and X-ray crystal structure of dichloro[S-1-phenyl-N-(S- pyrrolidin-2-ylmethyl)ethanamine]zinc(II) and its catalytic application to rac-lactide polymerization
Nayab, Saira,Lee, Hyosun,Jeong, Jong Hwa
, p. 405 - 409 (2011)
New dichloro zinc(II) complex ligated by the homochiral bidentate ligand S-1-phenyl-N-(S-pyrrolidin-2-ylmethyl)ethanamine (PPMA) was synthesized and characterized by X-ray crystallography. The geometry of the (PPMA)ZnCl 2 is a distorted tetrahe
Direct asymmetric aldol reactions catalysed by trans-4-hydroxy-(S)-prolinamide in solvent-free conditions
Yadav, Geeta Devi,Singh, Surendra
, p. 1156 - 1166 (2015/10/28)
Direct asymmetric aldol reactions between 4-nitrobenzaldehyde and cyclohexanone were catalysed by trans-4-hydroxy-(S)-prolinamide (10 mol %) in the presence of CH3COOH (10 mol %) as the co-catalyst under solvent-free conditions at 15 °C. (2S,4R)-4-Hydroxy-N-((S)-1-phenylethyl)pyrrolidine-2-carboxamide 2 efficiently catalysed the asymmetric aldol reaction to afford the product in >99% yield and with 95% ee with an anti/syn ratio of 88:12 after 18 h. The additional trans-hydroxyl group on (S)-prolinamide and (S)-1-phenylethylamine both influenced the ee of the predominant anti aldol product. Different benzaldehyde derivatives with cyclohexanone gave the corresponding aldol products in 38-89% yields and with 56-94% ee with anti/syn (100:0-71:29). Catalyst 2 can be used up to 5 continuous cycles for asymmetric aldol reactions between 4-nitrobenzaldehyde and cyclohexanone with overall 91% yield and 86% yield of anti-product with anti/syn (98:2).
Highly modular dipeptide-like organocatalysts for direct asymmetric aldol reactions in brine
Hu, Xiao-Mu,Zhang, Dong-Xu,Zhang, Sheng-Yong,Wang, Ping-An
, p. 39557 - 39564 (2015/05/20)
A novel series of dipeptide-like organocatalysts derived from proline, amino acids and primary amines have been prepared for direct asymmetric aldol reactions between various aromatic aldehydes and acetone to afford aldol products in good yields (up to 82%) and moderate enantioselectivities (up to 67% ee) with only 1 mol% of catalyst-loading in brine. Under the same conditions, the direct asymmetric aldol reactions of aromatic aldehydes and cyclohexanone give aldol products with high yields (up to 91%) and moderate to good enantioselectivities (up to 88% ee) and excellent diastereoselectivities (up to 99% dr). These organocatalysts are easily synthesized from commercially available materials in multi-gram scale with high modularity in their structural and stereogenic properties.