Additive-controlled regioselective direct asymmetric aldol reaction of hydroxyacetone and aldehyde
作者:Ling-yan Liu、Bing Wang、Yunna Zhu、Wei-xing Chang、Jing Li
DOI:10.1016/j.tetasy.2013.03.018
日期:2013.5
developed for the directasymmetricaldolreaction of hydroxyacetone and various aldehydes with moderate to high yields and high enantioselectivities. More importantly, this regioselective reaction could be easily regulated by changing the additives in the presence of the same organocatalyst 1b, to afford the normal 1,2-diol adducts and the disfavoured 1,4-diol products, respectively, in a highly regioselective
[reaction: see text] L-Proline-based small peptides have been developed as efficient catalysts for the asymmetricdirectaldolreactions of hydroxyacetone with aldehydes. Chiral 1,4-diols 7, which are disfavored products in similar aldolreactions catalyzed by either aldolases or L-proline, were obtained in high yields and enantioselectivities of up to 96% ee with peptides 3 and 4 in aqueous media.
Organocatalyzed Highly Enantioselective Direct Aldol Reactions of Aldehydes with Hydroxyacetone and Fluoroacetone in Aqueous Media: The Use of Water To Control Regioselectivity
作者:Xiao-Hua Chen、Shi-Wei Luo、Zhuo Tang、Lin-Feng Cun、Ai-Qiao Mi、Yao-Zhong Jiang、Liu-Zhu Gong
DOI:10.1002/chem.200600801
日期:2007.1.2
exhibited high regio- and enantioselectivities for the directaldolreactions of hydroxyacetone and fluoroacetone with aldehydes in aqueous media. It was found that water could be used to control the regioselectivity. The presence of 20-30 mol% of the catalyst afforded the directaldolreactions of a wide range of aldehydes with hydroxyacetone to give the otherwise disfavored products with excellent