[3+2+1] cycloaddition involving alkynes, CO and bridging vinyliminium ligands in diiron complexes: a dinuclear version of the Dotz reaction?

The vinyliminium complex [Fe(2){mu g-eta(1):eta(3)-C(SiMe(3))=CHC=N(Me)(2)}(mu-CO)(CO)(Cp)(2)][SO(3)CF(3)] reacts with HC CR (R = CPh(2)OH), affording a mixture of the 2,4,6-trisubstituted oxo-eta(5)-cyclohexadienyl complex [Fe{eta(5)-C(6)H(2)O(NMe(2))(SiMe(3))-(R)}(Cp)], the 2,6-disubstituted phenol C(6)H(3)R'(NMe(2))OH (R' = CHPh(2)) and 1,2,4-trisubstituted ferrocene [1-NMe(2)-2-R-4-SiMe(3)-Fc]. The corresponding reaction with HC CR (R = CMe(2)OH) yields analogous products: [Fe{eta(5)-C(6)H(2)O-(NMe(2))(SiMe(3))(R')}(Cp)] (R' = CMe=CH(2)), the phenol C(6)H(3)R'(NMe(2))OH together with [1-NMe(2)-2-R-4-SiMe(3)-Fc].