Secondary–secondary diamine catalysts for the enantioselective Michael addition of cyclic ketones to nitroalkenes
作者:Sunil V. Pansare、Raie Lene Kirby
DOI:10.1016/j.tet.2009.03.093
日期:2009.6
ketone–nitroalkene Michael addition reaction. The stereoselectivity of the Michael addition is dependant on the pKa of the N-substituted aminomethyl pendant in these diamines. N′-Aryl aminomethyl pyrrolidines provide γ-nitroketones with moderate to good enantiomeric excess (65–92%). Removal of the hydrogen-bond donor group by N-methylation results in a dramatic reduction of enantioselectivity (average ee
衍生自S-脯氨酸的仲-仲二胺是酮-硝基烯烃迈克尔加成反应的有效催化剂。迈克尔加成的立体选择性是依赖于所述p ķ一个的Ñ取代在这些二胺氨基甲基挂件。N'-芳基氨基甲基吡咯烷提供的γ-硝基酮具有中等到良好的对映体过量(65-92%)。通过N-甲基化去除氢键供体基团导致对映选择性的显着降低(平均ee 6%)。