Carbon–fluorine activation by iron(I): organoiron ring transformation promoted by addition of tertiary phosphanes to a perfluorosulfanylvinyldiiron(I) complex
Abstract
The perfluorosulfanylvinyldiiron(I) complex
[{Fe(CO)
3
}
2
{µ-C(SMe)(CF
3
)C(CF
2
)}] 1 reacted with tertiary
phosphanes [L = PPh
3
or P(OMe)
3
] in
dichloromethane or chloroform at 60 °C to give high yields of
cycloferrathiapentadiene iron clusters. When the nucleophile was
PPh
3
, the salt 2 was obtained: formally, a
fluoride-ion transfer between two molecules of 1 generates the
anion
[{Fe(CO)
3
}
2
{µ-C(CF
3
)C(CF
3
)SMe}]
-
and addition of
PPh
3
at two separate sites produces the counter cation
[(Ph
3
P)(OC)
2
Fe{µ-CFC(PPh
3
)C(CF
3
)SMe}Fe(CO)
3
]
+
. In contrast,
with P(OMe)
3
the neutral derivative
[{Fe(CO)
3
}
2
{µ-CFC[PO(OMe)
2
]C(CF
3
)SMe}] 4 was formed. Thermally
induced C–F bond activation is a feature of these reactions. All
the reaction products have been characterized by elemental analysis and
IR,
1
H,
19
F,
31
P and
13
C NMR
spectroscopy. The solid-state structure of
[(Ph
3
P)(OC)
2
Fe{µ-CFC(PPh
3
)C(CF
3
)SMe}Fe(CO)
3
][{Fe(CO)
3
}
2
{µ-C(CF
3
)C(CF
3
)SMe
}] 2 has been established by single-crystal X-ray
analysis. The Fe–Fe bond in the cation
[2.716(2) Å] is appreciably longer than the
corresponding bond in the anion [2.570(2) Å].
Possible routes to the formation of 2 and 4 have been
investigated. The conversion of 1 into 4 has been
shown to involve an intermediate 3 which has been fully
characterized by
19
F,
31
P and
13
C NMR
spectroscopy.
Please wait while we load your content...
