The enzymatic asymmetric aldol reaction using acidic protease from Aspergillus usamii
摘要:
AUAP (acidic protease from Aspergillus usamii) could catalyze the direct aldol reactions between aromatic aldehydes and cyclic ketones in acetonitrile (MeCN) in the presence of water. The enantioselectivities of up to 88% ee and diastereoselectivities of up to 97:3 (anti/syn) were achieved. This new activity of protease expands the application of the biocatalyst and provides a novel example of enzymatic promiscuity. (C) 2012 Elsevier Ltd. All rights reserved.
Primary amine-metal Lewis acid bifunctional catalysts: the application to asymmetric direct aldol reactions
作者:Zhenghu Xu、Philias Daka、Hong Wang
DOI:10.1039/b912728c
日期:——
The first example of metal Lewis acid-primary amine bifunctional cooperative catalyst derived from primary amino acids was developed, and it was found to catalyze aldolreactions of cyclic ketones highly efficiently with very good to excellent stereoselectivities.
Primary amine-metal Lewis acid bifunctional catalysts based on a simple bidentate ligand: direct asymmetric aldol reaction
作者:Philias Daka、Zhenghu Xu、Alexandru Alexa、Hong Wang
DOI:10.1039/c0cc00917b
日期:——
A novel class of primary amine-metal Lewis acid bifunctionalcatalysts based on a bidentate ligand was developed. These catalysts were highly efficient in catalyzing the direct asymmetricaldolreactions of ketones offering excellent stereoselectivity. The aldolreactions required a low catalyst loading (2.5 mol%), and were water compatible.
Directasymmetric aldol reactions of aldehydes with ketones inthe presence of a catalyticamount of β-aminosulfonamide 2 and trifluoroacetic acid in brine resultsin the formation of the corresponding ANTI-aldolproducts in high yields with up to 96% enantiomeric excess.The ANTI-aldol products obtained by using organocatalyst 2 have the opposite absolute configurationto those obtained using the similar
A fluorous organocatalyst promotes directasymmetricaldolreactions of aromatic aldehydes with ketones in brine to afford the corresponding anti-aldol products in high yield with up to 96% ee. Fluorous organocatalyst can be readily recovered by solid phase extraction using fluorous silica gel and reused without purification.
Aldol Reactions in Water Using a β-Cyclodextrin-Binding Proline Derivative
作者:Wolf-D. Woggon、Kegang Liu、Daniel Häussinger
DOI:10.1055/s-2007-985569
日期:——
The aldol reaction of various aromatic aldehydes with cyclohexanone is catalyzed by the inclusion complex of a proline derivative and β-cyclodextrin in water, yielding hydroxyketones with anti/syn ratio of up to 99:1 and ee values well above 90%.