Portal de Periódicos da CAPES

Solvolysis of 1-Decenyl(phenyl)iodonium Tetrafluoroborate: Mechanisms of Nucleophilic Substitution and Elimination

2001; Oxford University Press; Volume: 74; Issue: 3 Linguagem: Inglês

10.1246/bcsj.74.543

1348-0634

Tadashi Okuyama, Shohei Imamura, Yoshimi Ishida,

Porphyrin and Phthalocyanine Chemistry

Abstract Solvolysis of (E)-1-decenyl(phenyl)iodonium tetrafluoroborate 1 was carried out in some alcohols, acetic acid, and mixed aqueous alcoholic solvents at 50–60 °C and the effects of added carboxylates and other salts were also examined in methanol. Reaction products include enol derivatives (substitution) and 1-decyne (elimination) as well as iodobenzene. Rates for the solvolysis increase with increasing nucleophilicity of the solvent but have no correlation with the solvent ionizing power. The substitution occurs mostly via inversion of configuration, and is concluded to follow the in-plane SN2 mechanism with a minor concomitant out-of-plane SN2 pathway. The reactions with the deuterated substrates show that stronger bases of pKa of the conjugate acid > 3 induce exclusively α-elimination of 1 in methanol. However, both α- and β-elimination occur in neutral methanol in a ratio of about 3/1 besides the substitution. Mechanisms for these reactions are proposed.