School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
Angew Chem Int Ed Engl. 2023 Mar 27;62(14):e202217225. doi: 10.1002/anie.202217225. Epub 2023 Feb 20.
Without chiral induction the emergence of homochirality from achiral molecules is rather serendipitous, as the rationale is somewhat ambiguous. We herein provide a plausible solution. From achiral precursors are formed a pair of interconverting cage conformers that exhibit a C -axis as the only symmetry element. When their interconversion is impeded with intramolecular H-bonding, each conformer self-sorts into a homochiral crystal, which is driven by a helical network of multivalent intermolecular interactions during the self-assembly of homochiral cage conformers. As no chiral induction is involved throughout, we believe our study could enlighten the rational design for the emergence of homochirality with several criteria: 1) formation of a molecule without inversion center or mirror plane; 2) suppression of the enantiomeric interconversion, and introduction of multivalent interactions along the helical trajectory of screw symmetry within the resulting superstructure.
没有手性诱导,手性从非手性分子中出现是相当偶然的,因为其原理有些模糊。我们在此提供了一个合理的解决方案。从非手性前体形成一对可相互转化的笼状构象异构体,它们表现出 C 轴作为唯一的对称元素。当它们的相互转化受到分子内氢键的阻碍时,每个构象异构体都会自行分类为手性晶体,这是由手性笼状构象异构体自组装过程中的多价分子间相互作用的螺旋网络驱动的。由于整个过程中没有手性诱导,我们相信我们的研究可以为满足以下几个标准的手性出现的合理设计提供启示:1)形成没有反转中心或镜像平面的分子;2)抑制对映异构体的相互转化,并沿着螺旋对称的螺旋轨迹引入多价相互作用,形成超结构。