Studies on Lewis-Acid Induced Reactions of 8-Methoxy[2.2]metacyclophanes: A New Synthetic Route to Alkylated Pyrenes

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

Abstract

Anti-8-methoxy[2.2]metacyclophanes (MCPs) 5 a–b were obtained via pyrolysis of the corresponding syn-thiatetraoxide cyclophanes 4 a–b. Coupling reactions of 4-tert-butyl-1-methoxy-2,6-bis(mercaptomethyl)benzenes 1 a–b and 1,5-bis(chloro-methyl)-2,4-dimethylbenzene 2 under high dilution conditions afforded only the syn-conformers of 9-methoxy-2,11-dithia[3.3]metacyclophanes 3 a–b, which with m-CPBA formed the corresponding syn-tetraoxides 4 a–b. Lewis acid (TICl4/AlCl3-MeNO2) or iodine-catalyzed reactions of 5 b under various conditions led to transannular cyclization to afford tetrahydropyrene 6 b and pyrene derivative 7 b and/or de-tert-butylated 6 a. Iodine-catalyzed reaction of 5 a afforded tetrahydropyrene 6 a. These findings suggest the potential for a new route to alkylated pyrenes via strained and alkylated metacyclophanes. Density functional theory (DFT) studies were carried out to investigate the conformational characteristics of 3–5.

Citation

Monarul Islam, M., Feng, X., Wang, C. Z., Rahman, S., Alodhayb, A., Georghiou, P. E., Matsumoto, T., Tanaka, J., Redshaw, C., & Yamato, T. (2020). Studies on Lewis-Acid Induced Reactions of 8-Methoxy[2.2]metacyclophanes: A New Synthetic Route to Alkylated Pyrenes. ChemistrySelect, 5(4), 1269-1274. https://doi.org/10.1002/slct.201903048

• Journal Article Type: Article
• Acceptance Date: Jan 8, 2020
• Online Publication Date: Jan 24, 2020
• Publication Date: Jan 31, 2020
• Deposit Date: Dec 8, 2020
• Publicly Available Date: Jan 25, 2021
• Journal: ChemistrySelect
• Electronic ISSN: 2365-6549
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 5
• Issue: 4
• Pages: 1269-1274
• DOI: https://doi.org/10.1002/slct.201903048
• Keywords: DFT computations; Lewis acids; Metacyclophanes; Ring strain; Syn-anti conformers; Transannular cyclizations; Trans-tert-butylation
• Public URL: https://hull-repository.worktribe.com/output/3621758
• Publisher URL: https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/slct.201903048