Synthesis and Structures of [2.n]Metacyclophan-1-enes and their Conversion to Highly Strained [2.n]Metacyclophane-1-ynes

Akther, Thamina; Islam, Md. Monarul; Kowser, Zannatul; Matsumoto, Taisuke; Tanaka, Junji; Rahman, Shofiur; Alodhayb, Abdullah; Georghiou, Paris E.; Redshaw, Carl; Yamato, Takehiko

Abstract

Syn-[2.n]metacyclophan-1-enes (n=5, 6, 8) are synthesized by the McMurry cyclization of 1,n-bis(3-formyl-4-methoxyphenyl)alkanes in good yields. Syn-[2.n]metacyclophan-1-enes (n= 6, 8) were converted to the highly strained syn-type [2.n] metacyclophane-1-ynes by successive bromination followed by dehydrobromination with KOBut. The attempted trapping reaction of [2.5]metacyclophane-1-yne by a Diels-Alder reaction with 1,3-diphenylisobenzofuran failed due to its smaller ring size and strained structure. The triple bonds in syn-[2.n]metacyclophane-1-ynes (n= 6,8) are distorted from linearity with the bond angles, 156.7° and 161.4° as shown by X-ray crystallographic analyses. A DFT (Density Functional Theory) computational study of the synthesized compounds was conducted to determine the stability of the different configurations.

Citation

Akther, T., Islam, M. M., Kowser, Z., Matsumoto, T., Tanaka, J., Rahman, S., Alodhayb, A., Georghiou, P. E., Redshaw, C., & Yamato, T. (2020). Synthesis and Structures of [2.n]Metacyclophan-1-enes and their Conversion to Highly Strained [2.n]Metacyclophane-1-ynes. European Journal of Organic Chemistry, 2020(27), 4167-4175. https://doi.org/10.1002/ejoc.202000548

• Journal Article Type: Article
• Acceptance Date: Jun 17, 2020
• Online Publication Date: Jun 17, 2020
• Publication Date: Jul 23, 2020
• Deposit Date: Jun 17, 2020
• Publicly Available Date: Jun 18, 2021
• Journal: European Journal of Organic Chemistry
• Print ISSN: 1434-193x
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 2020
• Issue: 27
• Pages: 4167-4175
• DOI: https://doi.org/10.1002/ejoc.202000548
• Keywords: [2.n]metacyclophan-1-ynes; Structures; strained molecule; Diels-Alder reaction; Conformational studies
• Public URL: https://hull-repository.worktribe.com/output/3523176
• Publisher URL: https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/ejoc.202000548