Highly sterically hindered binaphthalene-based monophosphane ligands: synthesis and application in stereoselective Suzuki–Miyaura reactions
作者:Michaela Mešková、Martin Putala
DOI:10.1016/j.tetasy.2013.06.007
日期:2013.8
A series of new sterically hindered (R)-(2′-aryl-1,1′-binaphthalene-2-yl)phosphanes with ortho-substituted phenyls as aryl groups were prepared via Negishi monoarylation of enantiopure 2,2′-dibromo-1,1′-binaphthalene followed by lithiation and quenching with diphenylphosphanyl or dicyclohexylphosphanyl chloride. These ligands were applied to the stereoselective Suzuki–Miyaura coupling for the preparation
一系列带有邻位的新的位阻(R)-(2'-芳基-1,1'-联萘-2-基)膦通过对映纯的2,2'-二溴-1,1'-联萘的Negishi单芳基化,然后锂化并用二苯基膦酰基或二环己基膦酰基氯淬灭,制备作为芳基的取代的苯基。这些配体被用于立体选择性的Suzuki-Miyaura偶联反应,以制备取代的联芳基。当增加配体的2'-芳基的阻碍时,对映选择性正相关。使用具有2,6-二甲氧基苯基芳基的性能最好的二苯基膦配体,可以以高至优异的收率(68–99%)和低至良好的ee(12–75%ee)制备各种芳基萘,后者可与使用其他手性单膦配体时报告的最佳值。