Design of Organocatalysts for Asymmetric Direct Syn-Aldol Reactions
作者:Xiao-Ying Xu、Yan-Zhao Wang、Liu-Zhu Gong
DOI:10.1021/ol701798x
日期:2007.10.1
Two new organocatalysts 3a and 3b, derived from L-leucine and (S)-beta-amino alcohols that were prepared from L-valine, were designed and afforded the direct syn-aldol reactions of a wide scope of aldehydes with various ketones with an excellent diastereomeric ratio of up to >20/1 and enantioselectivities of up to 99% ee.
An Enantioselective Recyclable Polystyrene-Supported Threonine-Derived Organocatalyst for Aldol Reactions
作者:Andrea H. Henseler、Carles Ayats、Miquel A. Pericàs
DOI:10.1002/adsc.201400033
日期:2014.5.26
amino acids covalently supported onto polystyrene through alkyne–azide cycloaddition reactions has been synthesized and evaluated as catalysts in asymmetric aldolreactions. A polymer‐supported threonine behaves as an easily recyclable, highly reactive and stereoselective (up to 99% ee) catalyst in the aldolreaction of both cyclic and acyclic ketone donors with aromatic aldehydes in aqueous environments