Asymmetric zinc-Reformatsky reaction of Evans chiral imide with acetophenones and its application to the stereoselective synthesis of triazole antifungal agents
作者:Luo-Ting Yu、Meng-Tsung Ho、Ching-Yao Chang、Teng-Kuei Yang
DOI:10.1016/j.tetasy.2007.03.015
日期:2007.5
Reformatsky-type reaction of Evans chiral imide with various acetophenones was studied. The chiral imido zinc enolate, which was formed through the metal–halogen exchange reaction of chiral α-bromopropionyl-2-oxazolidinones 2 with diethyl zinc under the catalysis of Ni(acac)2, performed the asymmetric zinc-Reformatsky reaction with activated α-haloacetophenones 3 to give the chiral β-hydroxyamide 4 in good
研究了Evans手性酰亚胺与各种苯乙酮的Ni(acac)2催化ZnEt 2介导的不对称Reformatsky型反应。在Ni(acac)2的催化下,手性α-溴丙酰基-2-恶唑烷二酮2与二乙基锌的金属-卤素交换反应形成的手性亚氨基烯酸锌烯醇盐,通过活化的α-进行不对称的锌-Reformatsky反应。 haloacetophenones 3,得到手性β羟基酰胺4以良好的收率和高比例顺式- (2- [R,3 - [R)异构体(高达> 97%)。这种新的不对称合成技术提供了一种实用的方法,可以合成用于三唑类抗真菌剂(如伏立康唑,拉伏康唑,TAK-187和RO-0094815)的通用手性构件5。