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Synthesis, structures and Lewis‐Acid‐Induced isomerization of 8‐Methoxy[2.2]metaparacyclophanes and a DFT study

Islam, Md. Monarul; Feng, Xing; Rahman, Shofiur; Georghiou, Paris E.; Matsumoto, Taisuke; Tanaka, Junji; Alodhayb, Abdullah; Redshaw, Carl; Yamato, Takehiko

Authors

Md. Monarul Islam

Xing Feng

Shofiur Rahman

Paris E. Georghiou

Taisuke Matsumoto

Junji Tanaka

Abdullah Alodhayb

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Professor Carl Redshaw C.Redshaw@hull.ac.uk
Professor of Inorganic Materials Chemistry and REF Lead for Chemistry

Takehiko Yamato



Abstract

Methyl substituted 8‐methoxy[2.2]MPCPs 8 a–b were obtained via thiacyclophane and its oxidized products. Lewis acid‐catalyzed (AlCl3‐MeNO2) reactions of 5‐tert‐butyl‐8‐methoxy‐12,13,15,16‐tetramethyl[2.2]MPCP 8 b under various conditions led to transannular cyclization and isomerization reactions, affording the considerably less‐strained 5‐tert‐butyl‐8‐methoxy[2.2]MPCP 9, 5‐tert‐butyl‐8‐hydroxy‐14,16,17,18‐tetramethyl[2.2]metacyclophane 10 and pyrene derivatives 11 and 12. However,on prolonging the reaction time to 3 h for 8 b, the major product is 5‐tert‐butyl‐8‐hydroxy[2.2]MPCP 10. These reactions are strongly affected by the size and properties of the C‐8 substitutents as well as the methyl substitutents on the para‐linked benzene rings, which increase the strain in the molecules. The 1H NMR spectra and X‐ray crystallographic analysis of 8 b revealed that it adopts a syn‐conformation both in solution and in the solid state.

Journal Article Type Article
Publication Date Apr 1, 2019
Journal ChemistrySelect
Electronic ISSN 2365-6549
Publisher Wiley
Peer Reviewed Peer Reviewed
Volume 4
Issue 13
Pages 3630-3635
APA6 Citation Islam, M. M., Feng, X., Rahman, S., Georghiou, P. E., Matsumoto, T., Tanaka, J., …Yamato, T. (2019). Synthesis, structures and Lewis‐Acid‐Induced isomerization of 8‐Methoxy[2.2]metaparacyclophanes and a DFT study. ChemistrySelect, 4(13), 3630-3635. https://doi.org/10.1002/slct.201900190
DOI https://doi.org/10.1002/slct.201900190
Keywords Isomerization; Lewis acid; Metaparacyclophane; Strain; Transannular reaction; Trans-tert-butylation
Publisher URL https://onlinelibrary.wiley.com/doi/full/10.1002/slct.201900190