bis有效地催化了涉及(E)-3-芳基-1-(吡啶-2-基-N-氧化氮)丙-2-烯-1-酮的Diels-Alder和1,3-偶极环加成反应。(恶唑啉)–Cu II配合物。环加合物的定量收率高达98% ee ; 绝对构型是通过X射线分析确定的。通过X射线分析确定的反应性络合物的结构与催化过程的立体化学结果完全一致(二烯或硝酮接近配位的吡啶-N-氧化物衍生物受阻面较小)。
Highly Enantioselective Nitrone Cycloadditions with 2-Alkenoyl Pyridine <i>N</i>-Oxides Catalyzed by Cu(II)−BOX Complexes
作者:Santiago Barroso、Gonzalo Blay、M. Carmen Muñoz、José R. Pedro
DOI:10.1021/ol102716e
日期:2011.2.4
Enantioselective nitrone cycloadditions with 2-alkenoyl pyridine N-oxides as dipolarophiles have been reported. The reaction is catalyzed by Cu(II)-BOX complexes to give the expected isoxazolidine products with high diastereo- and enantioselectivity.