Formation of Quaternary Stereogenic Centers by Copper-Catalyzed Asymmetric Conjugate Addition Reactions of Alkenylaluminums to Trisubstituted Enones
作者:Daniel Müller、Alexandre Alexakis
DOI:10.1002/chem.201302856
日期:2013.11.4
undergo asymmetric copper‐catalyzed conjugate addition (ACA) to β‐substituted enones allowing the formation of stereogenic all‐carbon quaternary centers. Phosphinamine–copper complexes proved to be particularly active and selective compared with phosphoramidite ligands. After extensive optimization, high enantioselectivities (up to 96 % ee) were obtained for the addition of alkenylalanes to β‐substituted
烯基铝经过不对称的铜催化共轭加成(ACA)至β取代的烯酮,从而形成立体立体的全碳四元中心。与亚磷酰胺配体相比,膦胺-铜络合物被证明具有特别的活性和选择性。经过广泛的优化后,将烯基丙氨酸添加到β-取代的烯酮中获得了很高的对映选择性(高达ee的96% )。为了产生芳基和烷基取代的烯基亲核试剂,探索了两种生成必需的烯基铝的策略。此外,首次将烷基取代的次膦胺(SimplePhos)配体鉴定为Cu催化的ACA的高效配体。