Organocatalytic Asymmetric<i>syn</i>-Aldol Reactions of Aldehydes with Long-Chain Aliphatic Ketones on Water and with Dihydroxyacetone in Organic Solvents
作者:Ming-Kui Zhu、Xiao-Ying Xu、Liu-Zhu Gong
DOI:10.1002/adsc.200800105
日期:2008.6.9
syn-aldol reaction of aliphatic ketones with aromatic aldehydes catalyzed by a primary amino acid-based organocatalyst afforded the syn-aldol adducts in high yields with excellent diastereo- and enantioselectivities (up to > 20/1 dr, >99% ee), and a highly enantioselective syn-aldol reaction of dihydroxyacetone with a variety of aldehydes in THF proceeded with 14/1 to >20/1 dr and 92 to >99% ee. Water not
脂族酮与伯醛基有机催化剂催化的脂肪醛酮与芳族醛的水上,不对称和直接的顺式-羟醛反应,可高收率地得到顺式-羟醛加合物,具有优异的非对映体和对映体选择性(最高> 20/1 dr,> 99%ee)和二羟基丙酮与多种醛在THF中的高度对映选择性顺丁烯醛反应以14/1至> 20/1 dr和92至> 99%ee进行。水不仅加速了反应,而且增强了对映选择性。这种积极的水效应可能是由于表面水分子在疏水界面处的侧基羟基与有机催化剂的酰胺氧之间形成的氢键而产生的,这增加了酰胺NH的酸度,从而增强了与水合形成的相关氢键。醛。