Platinum-Catalyzed Hydrofluorination of Alkynes: Hydrogen Bonding to Indolylphosphine Ligands to Provide Fluoride Reactivity.

ABSTRACT: The reaction of the Pt complexes cis-[Pt(CH₃ )₂ {R₂ P(Ind)}₂ ] (Ind=2-(3-methyl)indolyl, R=Ph (1 a), 4-FC₆ H₄ (1 b), 4-CF₃ C₆ H₄ (1 c)) with HF afforded the fluorido complexes trans-[Pt(F(HF)₂ )(CH₃ ){R₂ P(Ind)}₂ ] 2 a-c, which can be converted into trans-[Pt(F)(CH₃ ){R₂ P(Ind)}₂ ] (3 a-c) by treatment with CsF. Addition of 3-hexyne to 2 a-c gave alkyne complexes trans-[Pt(C,C-η² -C₂ H₅ C≡CC₂ H₅ )(CH₃ ){R₂ P(Ind)}₂ {F(HF)₂ }] (4 a-c) at which a fluoride is stabilised as polyfluoride in the coordination sphere by hydrogen bonding to the indolyl-substituted phosphine ligands. Subsequent heating of a solution of 4 a in the presence of PVPHF led to fluoroalkene formation. Selective catalytic hydrofluorination of alkynes to yield (Z)-fluoroalkenes were developed. The ability of hydrogen bonding to polyfluoride favours the fluorination step as demonstrated by studies with complexes bearing no indolyl groups at the phosphine ligands.

SUBMITTER: Sander S 

PROVIDER: S-EPMC9401575 | biostudies-literature | 2022 Jul

REPOSITORIES: biostudies-literature