recognized for its obvious advantages cheap and readily available. A new type of prolinamide organocatalysts, derived from carbohydrate, was synthesized in high yield, and the novel organocatalysts were applied to the direct asymmetric aldolreactions of cyclohexanone and various aromatic aldehydes. The corresponding aldol products were obtained in high yields (up to 99%) with excellent diastereoselectivities
An Acid/Base-Regulated Recyclable Strategy for Homogeneous Cinchona Alkaloid-Derived Primary Amine Organocatalysts in Aldol, Vinylogous Michael and Double-Michael Cascade Reactions
作者:Jingwei Wan、Zhiwei Zhao、Falu Wang、Xuebing Ma
DOI:10.1002/ejoc.201500566
日期:2015.9
reusability of the organocatalysts epi-CDNH2, DeMe-QNNH2 and H-CDNH2 over three cycles was investigated in detail. It was found that the organocatalysts were highly effective with respect to catalytic performance, including the yields and stereoselectivities. Furthermore, the recovered organocatalysts in the tenth cycle retained similar excellent enantioselectivities to fresh organocatalysts. However, the
Recoverable silica-gel supported binam-prolinamides as organocatalysts for the enantioselective solvent-free intra- and intermolecular aldol reaction
作者:Abraham Bañón-Caballero、Gabriela Guillena、Carmen Nájera、Enrico Faggi、Rosa María Sebastián、Adelina Vallribera
DOI:10.1016/j.tet.2012.11.097
日期:2013.1
supported binam-derived prolinamides are efficient organocatalysts for the direct intramolecular and intermolecular aldol reaction under solvent-free conditions using conventional magnetic stirring. These organocatalysts in combination with benzoic acid showed similar results to those obtained under similar homogeneous reaction conditions using an organocatalyst of related structure. For the intermolecular process