An N-Heterocyclic Carbene/Lewis Acid Strategy for the Stereoselective Synthesis of Spirooxindole Lactones
作者:Julien Dugal-Tessier、Elizabeth A. O'Bryan、Thomas B. H. Schroeder、Daniel T. Cohen、Karl A. Scheidt
DOI:10.1002/anie.201201643
日期:2012.5.14
cooperative catalysis approach for the enantioselective formal [3+2] addition of α,β‐unsaturated aldehydes to isatins has been developed. Homoenolate annulations of β‐aryl enals catalyzed by an N‐heterocyclic carbene (NHC) require the addition of lithium chloride for high levels of enantioselectivity. This NHC‐catalyzed annulation has been used for the total synthesis of maremycin B.
α,β-不饱和醛与靛红的对映选择性正式[3+2]加成协同催化方法已被开发。由 N-杂环卡宾 (NHC) 催化的 β-芳基烯醛的均烯化环需要添加氯化锂以获得高水平的对映选择性。这种 NHC 催化的环化已用于马雷霉素 B 的全合成。