Phosphine-Catalyzed Aryne Oligomerization: Direct Access to α,ω-Bisfunctionalized Oligo(ortho-arylenes)

Bürger, Marcel; Ehrhardt, Nadine; Barber, Thomas; Ball, Liam T.; Namyslo, Jan C.; Jones, Peter G.; Werz, Daniel B.

Abstract

A phosphine-catalyzed oligomerization of arynes using selenocyanates was developed. The use of JohnPhos as a bulky phosphine is the key to accessing α,ω-bisfunctionalized oligo(ortho-arylenes) with RSe as the substituent at one terminus and CN as the substituent at the other. The in situ formation of R3PSeR′ cations, serving as sterically encumbered electrophiles, hinders the immediate reaction that affords the 1,2-bisfunctionalization product and instead opens a competitive pathway leading to oligomerization. Various optimized conditions for the predominant formation of dimers, but also for higher oligomers such as trimers and tetramers, were developed. Depending on the electronic properties of the electrophilic reaction partner, even compounds up to octamers were isolated. Optimization experiments revealed that a properly tuned phosphine as catalyst is of crucial importance. Mechanistic studies demonstrated that the cascade starts with the attack of cyanide; aryne insertion into n-mers leading to (n+1)-mers was ruled out.

Citation

Bürger, M., Ehrhardt, N., Barber, T., Ball, L. T., Namyslo, J. C., Jones, P. G., & Werz, D. B. (2021). Phosphine-Catalyzed Aryne Oligomerization: Direct Access to α,ω-Bisfunctionalized Oligo(ortho-arylenes). Journal of the American Chemical Society, 143(40), 16796-16803. https://doi.org/10.1021/jacs.1c08689

• Journal Article Type: Article
• Acceptance Date: Sep 17, 2021
• Online Publication Date: Sep 29, 2021
• Publication Date: Oct 13, 2021
• Deposit Date: Oct 4, 2021
• Publicly Available Date: Sep 30, 2022
• Journal: Journal of the American Chemical Society
• Print ISSN: 0002-7863
• Electronic ISSN: 1520-5126
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 143
• Issue: 40
• Pages: 16796-16803
• DOI: https://doi.org/10.1021/jacs.1c08689
• Keywords: Colloid and Surface Chemistry; Biochemistry; General Chemistry; Catalysis
• Public URL: https://nottingham-repository.worktribe.com/output/6390699
• Publisher URL: https://pubs.acs.org/doi/10.1021/jacs.1c08689
• Additional Information: This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of the American Chemical Society copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/jacs.1c08689