Enantioselective Chromatographic Resolution and One-Pot Synthesis of Enantiomerically Pure Sulfoxides over a Homochiral Zn-Organic Framework

摘要

The growing interest to porous metal-organic frameworks (MOFs), especially with respect to their potential applications (such as sorption and storage as well as catalysis and separation) is apparent in the literature in the past few years. The incorporation of enantiomerically pure homochiral building blocks into mi-croporous materials has been an ambitious goal and creates potential opportunities for separation of enantiomers as well as for chiral synthesis and catalysis. However, examples of enantioselective sorption and/or enantioseparation are still rather rare in the literature, and no preparative chromatographic enantioseparations over enantiopure MOFs have been reported so far. Recently, we published the synthesis of 3D porous Zn-organic framework [Zn_2-(bdc)(L-lac)(dmf)]·DMF (l) (where bdc = p-benzenedicarboxylic acid, dmf = N, N'-dimethylformamide), possessing the intrinsic chirality due to the chiral L-lac (= L-lactic acid) and displaying both catalytic and enantioselective sorption properties. In this study, we present the more detailed quantitative study of the enantioselective sorption properties of 1, as well as the first example of chiral chromatographic column for the separation of racemic mixtures of chiral alkyl aryl sulfoxides over the enantiopure porous metal— organic framework as the stationary phase. Ultimately, by combining both chromatographic and catalytic properties of 1 we developed a unique one-pot process for the synthesis of enantiomerically pure sulfoxides.