Cyclic and Macrocyclic Molecules Containing Silicon or Tin - Synthesis of Highly Rigid, Potentially Lewis-Acidic Cryptands

Herein we report the syntheses of highly rigid silicon- and tin-containing cyclic and bicyclic compounds with unsaturated organic backbones. The syntheses proceed via di-lithiated diethynylbenzene derivatives. The protocols for the known precursor compounds were significantly improved in a two-step one-pot reaction with yields up to 45% by alternating addition of the lithiation reagent and starting material. A total of ten compounds were synthesized and the molecular structure in the solid state was elucidated for six novel compounds. Host-guest-experiments with selected molecules were conducted to investigate on the potential of the complexation of small anions. All compounds were characterized by multinuclear NMR spectroscopy and elemental analyses or mass spectrometry and in most parts by SC-XRD analyses.

Automated summary

In this study, highly rigid cyclic and bicyclic compounds containing silicon and tin were synthesized using di-lithiated diethynylbenzene derivatives. The known precursor compounds were efficiently synthesized in a two-step one-pot reaction, resulting in yields up to 45% by alternating addition of the lithiation reagent and starting material. A total of ten compounds were synthesized, with the molecular structure in the solid state elucidated for six novel compounds. Host-guest experiments were conducted to investigate the potential of complexation of small anions using selected molecules. All compounds were characterized using various analytical techniques.