Chiral Self-sorting of Giant Cubic [8+12] Salicylimine Cage Compounds

Angew Chem Int Ed Engl. 2021 Apr 12;60(16):8896-8904. doi: 10.1002/anie.202016592. Epub 2021 Mar 8.

Abstract

Chiral self-sorting is intricately connected to the complicated chiral processes observed in nature and no artificial systems of comparably complexity have been generated by chemists. However, only a few examples of purely organic molecules have been reported so far, where the self-sorting process could be controlled. Herein, we describe the chiral self-sorting of large cubic [8+12] salicylimine cage compounds based on a chiral TBTQ precursor. Out of 23 possible cage isomers only the enantiopure and a meso cage were observed to be formed, which have been unambiguously characterized by single crystal X-ray diffraction. Furthermore, by careful choice of solvent the formation of meso cage could be controlled. With internal diameters of din =3.3-3.5 nm these cages are among the largest organic cage compounds characterized and show very high specific surface areas up to approx. 1500 m2 g-1 after desolvation.

Keywords: cage compounds; chiral; imine; self-sorting; tribenzotriquinacene.