Efficient Route to Atropisomeric Ligands – Application to the Synthesis of MeOBIPHEP Analogues
作者:Lucie Leseurre、Florent Le Boucher d’Herouville、Kurt Püntener、Michelangelo Scalone、Jean-Pierre Genêt、Véronique Michelet
DOI:10.1021/ol2011874
日期:2011.6.17
A highly efficient Pd-catalyzed P-C coupling reaction of easily accessible atropisomeric bisphosphane is described in the presence of various electron-poor aromatic iodides. The reactions are conducted in the presence of a Pd(II)/dppf catalyst in acetonitrile at 80 degrees C. The reaction conditions are compatible with several electron-withdrawing groups such as esters, cyano, chloro, and trifluoromethyl groups and lead to atropisomeric MeOBIPHEP derivatives in good to excellent yields and high enantiomeric purities.
Synthesis of New Water-Soluble Atropisomeric Ligands Derived from the MeOBIPHEP Skeleton: Applications for Asymmetric CH Bond Formation and Mechanistic Studies
We have extended the methodology developed for the preparation of atropisomeric chiral ligandsderivedfrom the MeOBIPHEPligand to water-soluble ones. The hydrophilic ligands bearing sodium carboxylate and methylammonium chloride moieties were easily synthesized under mild conditions in a short sequence and in high yields. Their solubility and acid/base properties were also determined. The ruthenium(II)
我们将为制备从MeOBIPHEP配体衍生的阻转异构手性配体而开发的方法扩展至水溶性。带有羧酸钠和甲基氯化铵部分的亲水配体很容易在温和条件下以短序列和高收率合成。还确定了它们的溶解度和酸/碱性质。含有4-CO 2 Na-和3,5-(CO 2 Na)2取代的MeOBIPHEP类似物的钌(II)催化剂表现出出色的活性,并得到了衣康酸二甲酯和2-(4- ee s≥92%的氟苯基)-3-甲基巴豆酸。D 2中后一种底物的不对称氢化研究O作为溶剂提供了对该机理的认识。