Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science & Technology, Shanghai, 200237, China.
Nat Commun. 2022 Aug 12;13(1):4735. doi: 10.1038/s41467-022-32432-8.
Molecular conformations induced by the rotation about single bonds play a crucial role in chemical transformations. Revealing the relationship between the conformations of chiral catalysts and the enantiodiscrimination is a formidable challenge due to the great difficulty in isolating the conformers. Herein, we report a chiral catalytic system composed of an achiral catalytically active unit and an axially chiral 1,1'-bi-2-naphthol (BINOL) unit which are connected via a C-O single bond. The two conformers of the catalyst induced by the rotation about the C-O bond, are determined via single-crystal X-ray diffraction and found to respectively lead to the formation of highly important axially chiral 1,1'-binaphthyl-2,2'-diamine (BINAM) and 2-amino-2'-hydroxy-1,1'-binaphthyl (NOBIN) derivatives in high yields (up to 98%), with excellent enantioselectivities (up to 98:2 e.r.) and opposite absolute configurations. The results highlight the importance of conformational dynamics of chiral catalysts in asymmetric catalysis.
单键旋转引起的分子构象在化学转化中起着至关重要的作用。由于难以分离构象体，揭示手性催化剂构象与对映体选择性之间的关系是一项艰巨的挑战。在此，我们报告了一种由非手性催化活性单元和轴向手性 1,1'-联萘酚（BINOL）单元组成的手性催化体系，它们通过 C-O 单键连接。通过单晶 X 射线衍射确定了催化剂中由 C-O 键旋转引起的两种构象体，并发现它们分别导致高度重要的轴向手性 1,1'-联萘-2,2'-二胺（BINAM）和 2-氨基-2'-羟基-1,1'-联萘（NOBIN）衍生物以高产率（高达 98%）和优异的对映选择性（高达 98:2 e.r.）和相反的绝对构型形成。结果强调了手性催化剂构象动力学在手性催化中的重要性。
