Chiral Bisguanidine-Catalyzed Inverse-Electron-Demand Hetero-Diels−Alder Reaction of Chalcones with Azlactones
作者:Shunxi Dong、Xiaohua Liu、Xiaohong Chen、Fang Mei、Yulong Zhang、Bo Gao、Lili Lin、Xiaoming Feng
DOI:10.1021/ja1046928
日期:2010.8.11
A new type of C(2)-symmetric chiral bisguanidine was designed as a highly efficient catalyst in the inverse-electron-demand hetero-Diels-Alder reaction of chalcones with azlactones for the first time. A wide variety of gamma,delta-unsaturated delta-lactone derivatives with alpha-quaternary-beta-tertiary stereocenters were obtained in high yields (up to 88%) with excellent enantioselectivities (up to
首次设计了一种新型的 C(2)-对称手性双胍,作为一种高效催化剂,用于查尔酮与 azlactones 的逆电子需求异质 Diels-Alder 反应。以高产率(高达 88%)和优异的对映选择性(高达 99% ee)获得了多种具有 alpha-quaternary-beta-tertiary 立体中心的 γ,delta-不饱和 delta-内酯衍生物。氢键被认为是反应的活化和立体诱导的关键。在所有情况下,主要是 HDA 加合物,它是作为单一非对映异构体与少量迈克尔加成产物一起获得的。