Synthesis and Crystal Structure Determination of 4’,9’,4”,9”-Tetra-<i>t</i>-Butyl- 1’,6’,1”,6”-Tetramethoxy-2,5-Dithia[3.3] Metabiphenylophane

Abstract

The title compound 4',9',4",9"-tetra-tert-butyl-1',6',1",6"-tetramethoxy-2,5-dithia[3.3] metabiphenylophane was synthesized as a calixarene like large-sized metacyclophane from the corresponding 3,3'-bis(chloromethyl)-5,5'-bis(1,1-dimethylethyl)-2,2'-dimethoxy-1,1'-biphenyl and 3,3'-bis (mercaptomethyl)-5,5'-bis(1,1-dimethylethyl)-2,2'-dimethoxy-1,1'-biphenyl via an intermolecular condensation reaction. The compound was characterized using 1 H NMR spectroscopy and mass spectrometry. Its exact conformational structure was determined via single crystal X-ray diffraction analysis. The compound has quite strained 1,2-alternate like structure because of its two high dihedral angled and rigid biphenyl parts in the crystal. The crystal includes the two isomers as two different 1,2-alternate like conformers, and the ratio of the two isomers is 78:22.

Synthesis and Molecular Structures of Two Novel π-Conjugation Extended Dithia[3.3]metacyclophanes

“…In general, cyclic compounds such as small sized metacyclophanes have various conformations derived from their orientations of the aromatic parts [6]. As part of our ongoing research towards the synthesis and conformational analysis of various substituted [3.3]metacyclophanes [7] [8], in this study, we report the synthesis and absolute structure determination of two novel small-sized metacyclophanes having thiaether bridges and ethynyl substituents.…”