Asymmetric Mannich Reaction of Malonates with Aldimines Using Yb<sup>III</sup>-Pybox Complexes Supported on Self-Assembled Organic-Inorganic Hybrid Silica with an Imidazolium Framework
作者:Babak Karimi、Ehsan Jafari、Dieter Enders
DOI:10.1002/ejoc.201402713
日期:2014.11
and recyclable catalyst in the enantioselective Mannich reaction of malonate esters with N-Boc aldimines to afford the corresponding products in good yields and enantioselectivities. In particular, it has been shown that the use of catalyst A resulted in much superior enantioselectivities in comparison with either 1:2 Yb(OTf)3/3b on a periodic mesoporous organosilica with 10 percent imidazolium framework
Yb(OTf)3/iPr-pybox (3b) 固定在具有离子液相 (SAILP) 的自组装有机-无机杂化二氧化硅上(催化剂 A)在丙二酸酯与N-Boc 醛亚胺以良好的产率和对映选择性提供相应的产品。特别是,已经表明,与 1:2 Yb(OTf)3/3b 在具有 10% 咪唑鎓骨架的周期性介孔有机二氧化硅(催化剂 C)或包含在相同反应条件下,SAILP 上的 1:1 Yb(OTf)3/3b。催化剂 A 可以回收和重复使用至少四次,催化活性或对映选择性仅略有下降。