Synthesis and structure of a chiral areno-bridged [2.4]metacyclophane

Islam, Md.Monarul; Akther, Thamina; Matsumoto, Taisuke; Tanaka, Junji; Thuéry, Pierre; Redshaw, Carl; Yamato, Takehiko

Abstract

© 2017 Elsevier Ltd The reductive coupling reaction of 1,4-bis(3-acetyl-5-tert-butyl-2-methoxyphenyl)butane 3 was carried out using TiCl 4 -Zn in pyridine followed by a McMurry coupling reaction to afford the compounds anti and syn 1,2-dimethyl[2.4]MCP-1-ene 4. Bromination of 4 with BTMA-Br 3 in dry CH 2 Cl 2 afforded the interesting compound 1,2-bis-(bromomethyl)-5,15-di-tert-butyl-8,18-dimethoxy[2.4]MCP-1-ene 6 and consecutive debromination with Zn and AcOH in CH 2 Cl 2 solution afforded the stable solid 5,15-di-tert-butyl-8,18-dimethoxy-1,2-dimethylene[2.4]MCP 7 in 89% yield. Compound 7 was conveniently employed in a Diels–Alder reaction with dimethyl acetylenedicarboxylate (DMAD) to provide 2-(3′,6′-dihydrobenzo)-5,15-di-tert-butyl-8,18-dimethoxy[2.4] MCP-4′,5′-dimethylcarboxylate 8 in good yield. Diels–Alder adduct 8 was converted into a novel and inherently chiral areno-bridged compound [2.4]MCP 9 by aromatization. The chirality of the two conformers was characterized by circular dichroism (CD) spectra of the separated enantiomer which are perfect mirror images of each other.

Citation

Islam, M., Akther, T., Matsumoto, T., Tanaka, J., Thuéry, P., Redshaw, C., & Yamato, T. (2018). Synthesis and structure of a chiral areno-bridged [2.4]metacyclophane. Tetrahedron, 74(2), 329-335. https://doi.org/10.1016/j.tet.2017.11.075

• Journal Article Type: Article
• Acceptance Date: Nov 28, 2017
• Online Publication Date: Nov 29, 2017
• Publication Date: Jan 11, 2018
• Deposit Date: Mar 4, 2018
• Publicly Available Date: Nov 30, 2018
• Print ISSN: 0040-4020
• Electronic ISSN: 1464-5416
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 74
• Issue: 2
• Pages: 329-335
• DOI: https://doi.org/10.1016/j.tet.2017.11.075
• Keywords: Metacyclophane; McMurry reaction; Bromination; Diels–Alder reaction; Chirality
• Public URL: https://hull-repository.worktribe.com/output/710164
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0040402017312413
• Additional Information: This article is maintained by: Elsevier; Article Title: Synthesis and structure of a chiral areno-bridged [2.4]metacyclophane; Journal Title: Tetrahedron; CrossRef DOI link to publisher maintained version: http://dx.doi.org/10.1016/j.tet.2017.11.075; Content Type: article; Copyright: © 2017 Elsevier Ltd. All rights reserved.