Controlling the fluoridophilicity of sulfonium boranes via chelation, Coulombic and hydrophobic effects Academic Article uri icon

abstract

  • 2019 Elsevier Ltd We describe the synthesis and properties of a series of sulfonium boranes featuring a dimesitylboryl unit and a dimethylsulfonium or methylphenyl sulfonium moiety connected by an ortho- or para-phenylene linker. Acid-base and fluoride anion tritration experiments carried out in aqueous media indicate that [o-(Mes 2 B)C 6 H 4 (SMePh)] + is the most Lewis acidic derivative. Structural and computational analysis indicate that the favorable properties of this cationic borane derive from the proximity of the sulfonium and boryl units which enhances the Coulombic stabilization of the ensuing zwitterions o-(Mes 2 XB)C 6 H 4 (SMePh) with X = OH or F. Another important factor is the overall hydrophobicity of the sulfonium borane which, we propose, promotes anion desolvation, a factor also favoring B-X bond formation. Finally, the crystal structure of o-(Mes 2 FB)C 6 H 4 (SMePh) shows that the zwitterion is further stabilized by formation of a BFS chelate motif.

published proceedings

  • TETRAHEDRON

author list (cited authors)

  • Zhao, H., Kim, Y., Park, G., & Gabbai, F. P.

citation count

  • 3

complete list of authors

  • Zhao, Haiyan||Kim, Youngmin||Park, Gyeongjin||Gabbaii, Francois P

publication date

  • March 2019