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首次研究了Cu(CH3CN)4BF4/DTBM-BIPHEP催化的亚甲胺叶立德与环丙基亚甲基乙酸乙酯参与的不对称1,3-偶极环加成反应,获得了优异的exo-选择性,研究结果证实大空间位阻的手性双膦配体对反应的非对映选择性控制起到至关重要的影响;同时一步高效构建三个叔碳手性中心和一个螺环季碳中心.该不对称1,3-偶极环加成反应收率良好,得到优秀的非对映(>98∶2,dr)与对映选择性(ee值高达99%).该催化体系为合成exo构型的5-氮杂-螺[2,4]庚烷衍生物提供了一种简洁高效的方法,具有原子经济性好、反应条件温和、底物适用范围广等优点.
The asymmetric 1,3-dipolar cycloaddition reaction involving methylamine ylide and cyclopropylmethyleneacetate catalyzed by Cu (CH3CN) 4BF4 / DTBM-BIPHEP was first studied and excellent exo- The results of the study confirm that large sterically hindered chiral bisphosphine ligands play a crucial role in the diastereoselective control of the reaction while efficiently building three tertiary carbon chiral centers and one spirocyclic quaternary carbon The asymmetric 1,3-dipolar cycloaddition reaction gave good yields with excellent diastereomer (> 98: 2, dr) and enantioselectivity (ee values up to 99%). The catalytic system is Synthesis of exo configuration of 5-aza-spiro [2,4] heptane derivatives provides a simple and efficient method, with good atomic economy, mild reaction conditions, the advantages of a wide range of substrates.