A model for C–F activation by electrophilic phosphonium cations. Issue 54 (20th June 2017)

• Record Type: Journal Article
• Authors: Mallov, Ian; Johnstone, Timothy C.; Burns, Darcy C.; Stephan, Douglas W.
• Is Part Of: Chemical communications. Volume 53:Issue 54(2017)
• Page Start: 7529
• Page End: 7532
• Publication Date: 2017-06-20
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1039/c7cc04057a
• Languages: English
• ISSNs: 1359-7345

Abstract

Abstract : The electrophilic phosphonium cation (EPC) salt [C10 H6 (CF3 )PF(C6 F5 )2 ][B(C6 F5 )4 ]4 exhibited structural and spectroscopic features evidencing an interaction between the CF3 and fluorophosphonium units. It thus models a key step in the proposed mechanism of main group C–F activation. Abstract : The synthesis of the electrophilic phosphonium cation (EPC) salt [C10 H6 (CF3 )PF(C6 F5 )2 ][B(C6 F5 )4 ]4 was achieved via oxidation of phosphine [C10 H6 (CF3 )P(C6 F5 )2 ]2 with XeF2 to form phosphorane [C10 H6 (CF3 )PF2 (C6 F5 )2 ]3 and subsequent fluoride ion abstraction. Structural and spectroscopic characterization of4 provides evidence of an interaction between the CF3 functionality and the phosphonium centre. AIM and NBO analyses also support donation from a lone pair on a fluorine atom of the CF3 group to the P–F σ* orbital of the fluorophosphonium unit, consistent with previously proposed mechanisms for main group C–F bond activations.