Chiral phosphinoazomethinylate salts as new ‘one-step available’ ligands for copper-catalyzed asymmetric conjugate addition
作者:Joanna Wencel、Diane Rix、Thomas Jennequin、Stéphane Labat、Christophe Crévisy、Marc Mauduit
DOI:10.1016/j.tetasy.2008.07.011
日期:2008.8
report the use of phosphinoazomethinylate salts as chiral efficient ligands for the copper-catalyzed asymmetric conjugate addition (ACA) of dialkylzinc to various enones. These tridentate P,N,O ligands are straightforwardly obtained in a one-step procedure from commercially available enantiopure α-aminoacids. Performing the conjugate addition in the greener AcOEt solvent, high enantioselectivities were reached
在本文中,我们报道了膦基次甲基次膦酸酯盐作为手性有效的配位体,用于铜催化的二烷基锌向各种烯酮的不对称共轭加成(ACA)。这些三齿P,N,O配体可以一步一步从市售对映纯α-氨基酸直接获得。在较绿的AcOEt溶剂中进行共轭物加成,环状和非环状烯酮的对映选择性都达到了较高的对映选择性,分别介于72%到98%ee和96%到> 99%。获得高对映选择性所需的2/1 Cu /配体比率使我们设想了用于该转化的铜-铜双金属催化体系。