Dubey Ritesh, Yan KaKing, Kikuchi Takashi, Sairenji Shiho, Rossen Anouk, Goh Shermin S, Feringa Ben L, Fujita Makoto
Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo, 113-8656, Japan.
Rigaku Corporation, 3-9-12 Matsubara-cho, Akishima-shi, Tokyo, 196-8628, Japan.
Angew Chem Int Ed Engl. 2021 May 17;60(21):11809-11813. doi: 10.1002/anie.202102559. Epub 2021 Apr 15.
When chiral compounds with low enantiomeric excess (ee, R:S=m:n) were absorbed into the void of the crystalline sponge (CS), enantiomerically pure [(R) (S) ] chiral composites were formed, changing the centrosymmetric space group into non-centrosymmetric one. The absolute configuration of the analyte compounds was elucidated with a reasonable Flack (Parsons) parameter value. This phenomenon is characteristic to the "post-crystallization" in the pre-determined CS crystalline lattice, seldom found in common crystallization where the crystalline lattice is defined by an analyte itself. The results highlight the potential of the CS method for absolute configuration determination of low ee samples, an often encountered situation in asymmetric synthesis studies.
当对映体过量较低（ee，R:S = m:n）的手性化合物被吸收到晶体海绵（CS）的空隙中时，会形成对映体纯的[(R) (S) ]手性复合材料，将中心对称空间群转变为非中心对称空间群。通过合理的弗拉克（帕森斯）参数值阐明了分析物化合物的绝对构型。这种现象是预定CS晶格中“后结晶”的特征，在由分析物自身定义晶格的普通结晶中很少见。这些结果突出了CS方法在低ee样品绝对构型测定方面的潜力，这在不对称合成研究中是经常遇到的情况。
