Probing the Importance of the Hemilabile Site of Bis(phosphine) Monoxide Ligands in the Copper-Catalyzed Addition of Diethylzinc to <i>N</i>-Phosphinoylimines: Discovery of New Effective Chiral Ligands
作者:Isabelle Bonnaventure、André B. Charette
DOI:10.1021/jo800969x
日期:2008.8.1
hemilabile ligand Me-DuPHOS(O) 2 has proven to be a successful ligand for the copper-catalyzed addition of diethylzinc to N-phosphinoylimines. The corresponding α-chiral amines were obtained in high yields (80−98%) and enantiomeric ratios (19.0:1 to 99.0:1 er). Furthermore, this Cu•2 catalytic system has been shown to be effective in the addition of diethylzinc to nitroalkenes and in the reduction of β,β-disubstituted
半不稳定的配体Me-DuPHOS(O)2已被证明是铜催化将二乙基锌加成到N-膦基嘧啶中的成功配体。以高收率(80-98%)和对映体比率(19.0:1至99.0:1 er)获得了相应的α-手性胺。此外,已经表明该Cu 2催化体系在将二乙基锌添加到硝基烯烃中和减少β,β-二取代的乙烯基苯基砜方面是有效的。本文描述了一般的结构/选择性研究,其中三个配体亚基(手性磷酰基-连接基-不稳定的配位基团(Z))被系统地修饰,并在铜催化的二乙基锌加到N-膦基嘧啶1中进行了测试。衍生自苯甲醛。这项研究导致发现了一类新的有效手性配体,其结合了一个手性磷烷单元和一个非手性氧化膦。