Asymmetric activation of tropos catalysts in the stereoselective catalytic conjugate additions of R2Zn to α,β-enones: an efficient synthesis of (−)-muscone
作者:Patrizia Scafato、Giovanni Cunsolo、Stefania Labano、Carlo Rosini
DOI:10.1016/j.tet.2004.07.034
日期:2004.9
due only to atropisomerism and this molecule possesses a flexible biphenylamine residue. Therefore it can work as a tropos catalyst. The catalytic efficiency of this new phosphoramidite has been tested in some asymmetric conjugate additions of dialkylzinc reagents to α,β-enones and compared with that of an analogous already known non-tropos ligand. Interestingly, while comparable results were obtained
提出了从(R)-BINOL和联苯胺开始的新亚磷酰胺的制备。在这种化合物中,手性仅归因于阻转异构性,并且该分子具有柔性的联苯胺残基。因此,它可以作为对流催化剂。这种新的亚磷酰胺的催化效率已经在二烷基锌试剂向α,β-烯酮的一些不对称共轭加成中进行了测试,并与类似的已知非对位配体进行了比较。有趣的是,比较的结果是在加入ZnEt获得2到查耳酮和环己烯酮,在加法ZnMe的情况下2至(É)-cyclopentadec-2-en-1-one,新配体以84%ee的浓度提供(-)-muscone(香料行业的重要成分),而非Tropos配体的ee含量低得多(57%)价值。