Direct Asymmetric Michael Additions of Ketones to Nitroolefins and Chalcones Catalyzed by a Chiral C2-Symmetric Pyrrolidine-based Tetraamine

C2-Symmetric pyrrolidine-based tetraamine, available from commercially starting materials, showed good cata- lytic activity for asymmetric Michael additions of ketones to nitroalkenes especially to chalcones. The reactions proceeded to give the corresponding products in good yields and in a highly selective manner.

相转移催化剂催化亚胺与α,β不饱和酮的不对称Michael加成反应

金鸡纳碱衍生的季铵盐催化二苯亚甲基甘氨酸叔丁酯与α,β不饱和酮的不对称Michael加成反应,常温条件下取得99%的产率,达到57%的对映选择性以及高于20∶1的区域选择性.合成了7个未见文献报道的取代的甘氨酸衍生物,其结构得到1H NMR确证.

有机催化苯并三氮唑与查耳酮的不对称aza-Michael加成反应

将脯氨醇衍生物用于有机催化苯并三氮唑与查耳酮的不对称aza-Michael加成反应,制备手性氮杂环化合物。通过^1HNMR、^13CNMR和HR-MS光谱技术对其结构进行表征,通过HPLC手性色谱柱测定产品的对映体过量值（e.e.）。考察溶剂、温度及催化剂用量对反应立体选择性的影响,进而优化催化剂体系。结果表明,最佳催化条件为20 mol%催化剂,甲苯为溶剂,0℃下反应。将此条件用于7种不同取代查耳酮的反应,得到了58%-70%的收率和最高达72%的对映选择性,拓宽了该反应的催化剂类型和底物范围。

Asymmetric intramolecular oxa-Michael addition of activated α,β-unsaturated ketones by chiral N-triflyl phosphoramide

Asymmetric intramolecular oxa-Michael addition of activated α,β-unsaturated ketones by chiral N-triflyl phosphoramide was realized. The flavanone products can be synthesized with excellent yields (50%–95%) and up to 74% ee.