Ar-BINMOLs with Axial and sp3 Central Chirality - Characterization, Chiroptical Properties, and Application in Asymmetric Catalysis
作者:Guang Gao、Xing-Feng Bai、Hua-Meng Yang、Jian-Xiong Jiang、Guo-Qiao Lai、Li-Wen Xu
DOI:10.1002/ejoc.201100664
日期:2011.9
aromatic π–π/C–H···π interactions. In particular, CD measurements of chiral and racemic Ar-BINMOL 2a in solution and the solid state show a strong Cotton effect, which revealed that ampli-fication of chirality was observed because of the formation of a chiral supramolecular oligomer derived from the racemic monomer. To this end, the Ar-BINMOLs were used as supramolecular auxiliaries to mediate the Michael
2 -Hydroxy-1,1 -binaphthalene-2-(arylmethanol) (Ar-BINMOLs),一系列新的 1,1 -binaphthalene-2,2 -diol 衍生物,通过 [1,2]-Wittig 重排制备,被引入作为新的手性分子,用于基于 ESI-MS、核磁共振光谱、差示扫描量热法 (DSC) 和 X 射线衍射法研究超分子聚集模式。表征表明,Ar-BINMOLs 表现出与 BINOL 不同的特性,并且由于氢键和芳香族 π–π/C–H…π 相互作用而充当超分子。特别是,溶液和固态中手性和外消旋 Ar-BINMOL 2a 的 CD 测量显示出强烈的 Cotton 效应,这表明由于形成了衍生自外消旋单体的手性超分子低聚物,观察到手性的放大。为此,Ar-BINMOLs用作超分子助剂来介导蒽酮与(E)-β-硝基苯乙烯的迈克尔反应,并可以得到具有相当对映选择性的迈克尔加合物。此外,Ar-BINMOLs