A1 Journal article (refereed)
Exploiting the Chiral Ligands of Bis(imidazolinyl)- and Bis(oxazolinyl)thiophenes : Synthesis and Application in Cu-Catalyzed Friedel–Crafts Asymmetric Alkylation (2021)

Islam, M. S., Alammari, A. S., Barakat, A., Alshahrani, S., Haukka, M., & Al-Majid, A. M. (2021). Exploiting the Chiral Ligands of Bis(imidazolinyl)- and Bis(oxazolinyl)thiophenes : Synthesis and Application in Cu-Catalyzed Friedel–Crafts Asymmetric Alkylation. Molecules, 26(23), Article 7408. https://doi.org/10.3390/molecules26237408

JYU authors or editors

Publication details

All authors or editors: Islam, Mohammad Shahidul; Alammari, Abdullah Saleh; Barakat, Assem; Alshahrani, Saeed; Haukka, Matti; Al-Majid, Abdullah Mohammed

Journal or series: Molecules

eISSN: 1420-3049

Publication year: 2021

Publication date: 06/12/2021

Volume: 26

Issue number: 23

Article number: 7408

Publisher: MDPI AG

Publication country: Switzerland

Publication language: English

DOI: https://doi.org/10.3390/molecules26237408

Publication open access: Openly available

Publication channel open access: Open Access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/78933

Abstract

Five new C2-symmetric chiral ligands of 2,5-bis(imidazolinyl)thiophene (L1–L3) and 2,5-bis(oxazolinyl)thiophene (L4 and L5) were synthesized from thiophene-2,5-dicarboxylic acid (1) with enantiopure amino alcohols (4a–c) in excellent optical purity and chemical yield. The utility of these new chiral ligands for Friedel–Crafts asymmetric alkylation was explored. Subsequently, the optimized tridentate ligand L5 and Cu(OTf)2 catalyst (15 mol%) in toluene for 48 h promoted Friedel–Crafts asymmetric alkylation in moderate to good yields (up to 76%) and with good enantioselectivity (up to 81% ee). The bis(oxazolinyl)thiophene ligands were more potent than bis(imidazolinyl)thiophene analogues for the asymmetric induction of the Friedel–Crafts asymmetric alkylation.

Keywords: coordination complexes; ligands; catalysts; chemical synthesis

Free keywords: bis-oxazoline; bis-imidazoline; thiophene; indoles; β-nitroolefins; asymmetric catalysis; Friedel−Crafts alkylation

Contributing organizations

Ministry reporting: Yes

Reporting Year: 2021

JUFO rating: 1