Copper-Catalyzed Asymmetric Conjugate Addition of Trialkylaluminium Reagents to Trisubstituted Enones: Construction of Chiral Quaternary Centers
作者:Magali Vuagnoux-d'Augustin、Alexandre Alexakis
DOI:10.1002/chem.200701001
日期:2007.11.26
vinylalane species undergo enantioselective conjugate addition to a wide range of 2- or 3-substituted enones (cyclopent-2-enones, cyclohex-2-enones, 3-methyl cyclohept-2-enone) in the presence of catalytic amount of copper salt (copper thiophene carboxylate, [Cu(CH3CN)4]BF4 or [CuOTf]2C6H6) and tropos-phosphoramidite-based ligand. Thus, chiral quaternary centers can be built, with up to 98% ee after rigorous
在催化作用下,Me3Al,Et3Al和乙烯基丙烷类物质进行对映选择性共轭加成,生成各种2-或3-取代的烯酮(环戊-2-烯酮,环己-2-烯酮,3-甲基环庚-2-烯酮)铜盐(噻吩羧酸铜,[Cu(CH3CN)4] BF4或[CuOTf] 2C6H6)和基于对位亚磷酰胺的配体。因此,经过严格优化实验条件后,可以建立具有高达98%ee的手性四元中心。结果表明,主要的重要参数是试剂引入的顺序。然后,将生成的对映体富集的烯醇铝和手性共轭加合物官能化并用于随后的反应。