Abstractmagnified imageWe have synthesized chiral diamines that efficiently catalyze the syn‐ and anti‐aldol reactions in aqueous medium with high diastereo‐ and enantioselectivities. The product, thus obtained, was further reduced selectively to give syn‐configured 1,2,3‐triol, an important subunit present in various monosaccharides and natural products such as (+)‐boronolide.
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.