Fine-Tuning Monophosphine Ligands for Enhanced Enantioselectivity. Influence of Chiral Hemilabile Pendant Groups
作者:Aibin Zhang、T. V. RajanBabu
DOI:10.1021/ol0495063
日期:2004.4.1
[reaction: see text] C(2)-Symmetric P-(2-X-aryl)-2,5-dialkylphospholanes (X = dioxolan-2-yl or dioxan-2-yl), designed on the basis of a working model for asymmetric induction, are effective ligands for the Ni(II)-catalyzed asymmetric hydrovinylation of styrenes. Excellent yields (>99%), selectivities for the desired 3-arylbutenes (>99%), high S/C ratios (>1200), and ee's (up to 91%) have been realized for a
[反应:请参见文本] C(2)-对称的P-(2-X-芳基)-2,5-二烷基膦酸酯(X = dioxolan-2-yl或dioxan-2-yl),是根据工作原理设计的不对称诱导的模型是Ni(II)催化的苯乙烯不对称氢乙烯基化的有效配体。对于许多原型乙烯基芳烃,已经实现了优异的收率(> 99%),对所需3-芳基丁烯的选择性(> 99%),高S / C比(> 1200)和ee(最高91%)。在二氧戊环系列中,选择性取决于C(4)和C(5)()碳的构型。