A general AzePhenol dinuclear zinc catalytic system has been successfully developed and applied into the asymmetric Michael addition of 4-hydroxyl pyrones and 4-hydroxycoumarins to β,γ-unsaturated α-keto esters. Excellent yields (up to 99%) and high enantioselectivities (up to 94% ee) are obtained for a wide range of substrates under mild conditions in the absence of additives. This bimetallic catalytic
已成功开发出通用的AzePhenol双核
锌催化体系,并将其应用于将
4-羟基
吡喃酮和
4-羟基
香豆素不对称迈克尔加成到β,γ-不饱和α-
酮酸酯上。在温和条件下没有添加剂的情况下,对于多种底物,均具有出色的收率(最高99%)和高对映选择性(最高94%ee)。这种双
金属催化方法代表了一种新的有效的不对称合成方案,可以访问具有药理学意义的多种
生物活性化合物。提出了可能的机制来解释不对称感应的起源。