Carbon-fluorine bond cleavages and organoiron ring transformations: Reaction of a perfluorosulfanylvinyldiiron(I) complex with amines

The reaction of the perfluorosulfanylvinyldiiron(I) complex [{Fe(CO)(3)}(2){mu-C(SMe)(CF3)C-beta(CalphaF2)}] (1) with secondary mono- and diamines (L = Me2NH, (CH2)(4)NH, HN(CH2)(4)NH) in a 1:1 ratio in dichloromethane at room temperature led in a multistep reaction to the new monoaminocycloferrathiapentadiene compounds [{Fe(CO)(3)}(2){mu-S(Me)C(CF3)CFCX}] (X = NMe2 (2), N(CH2)(4) (3), N(CH2)(4)NH (4)) and [[{Fe(CO)(3)}(2){mu-S(Me)C(CF3)CFC](2){mu-N(CH2)(4)N}] (5). However, when the reaction of 1 was conducted in THF with a large excess of amine, the diaminocycloferrathiabutene complexes [{Fe(CO)(3)}(2){mu-S(Me)C(CF3)C(CX2)}] (X = NMe2 (6), N(CH2)(4) (7)) and [{Fe(CO)(3)}(2){mu-S(Me)C(CF3)C(CX)}] (X = MeN(CH2)(2)NMe (8), HN(CH2)(2) NH (9)) were formed. It is suggested that these compounds form via initial nucleophilic attack at C-alpha to give the common zwitterionic intermediate [{Fe(CO)(3)}(2){mu-S(Me)C(CF3)C(CFNX2)] (C). Thermally induced C-F bond activation is a feature of these reactions. Thermolysis of diaminocycloferrathiabutene compounds (6-9) in tetrahydrofuran gave the amidinium-substituted mu(parallel to)-alkyne derivatives [{Fe(CO)(3)}(2)(mu-SMe){mu-(CF3)C=C(CX2)}] (X = NMe2 (10), N(CH2)(4) (11)) and [{Fe(CO)(3)}(2)(mu-SMe){mu-(CF3)C=C(CX)}] (X = MeN(CH2)(2) NMe (12), NH(CH2)(2)NH (13)), in quantitative yields via C-S bond scission. The molecular structures of 6, 8, and 10 have been established by X-ray diffraction studies.