Proline-Catalyzed Ketone-Aldehyde Aldol Reactions are Accelerated by Water
作者:Petri Pihko、Annika Nyberg、Annina Usano
DOI:10.1055/s-2004-831296
日期:——
Proline-catalyzed aldol reactions between acetone or 4-thianone and different aldehydes are accelerated by addition of 1-10 equivalents of water to the reaction medium, allowing stoichiometric aldol reactions to proceed at acceptable rates.
Effect of additives on the proline-catalyzed ketone–aldehyde aldol reactions
作者:Petri M. Pihko、Katri M. Laurikainen、Annina Usano、Annika I. Nyberg、Jatta A. Kaavi
DOI:10.1016/j.tet.2005.09.070
日期:2006.1
The effect of bases, acids, and water as additives in proline-catalyzed ketone–aldehyde aldol reactions has been studied. While the reaction appears to be relatively tolerant to small amounts of tertiary amine bases or weak acids, it stops completely with strong acids. The use of water as an additive had a highly beneficial effect on reactions that were conducted with a stoichiometric ratio of ketone
The application of a structurally simple, recyclable, and large-scale l-prolinamide catalyst for asymmetric aldol reactions
作者:Zhi Guan、Yuan Luo、Bao-Qiang Zhang、Krystal Heinen、Da-Cheng Yang、Yan-Hong He
DOI:10.1016/j.tetasy.2014.04.009
日期:2014.5
With heterocyclic ketones or cyclohexanone, the aldolreactions gave products in high yields and with respectable enantioselectivities (87–99% ee) and diastereoselectivities (up to >99:1 anti/syn). The catalyst could be recycled and reused up to seven times resulting in good yields and with good selectivities. This catalyst is also efficient in large-scale reactions with the enantioselectivities remaining