Synthesis of diiron m-allenyl complexes by electrophilic addition to propen-2-dimetallacyclopentenone species: a joint experimental and DFT study

The propen-2-yl-dimetallacyclopentenone complex [Fe2Cp2(CO)(mu-CO){mu-eta(1):eta(3)-C-alpha(H)=C-beta(C-gamma(CH3)CH2)C(=O)}] (1) underwent electrophilic additions at the propenyl moiety to afford the mu-allenyl complexes [Fe2Cp2(CO)(2)(mu-CO){mu-eta(1):eta(2)(alpha,beta)-C alpha H=C-beta-C-gamma(CH3)(CH2E)}][BF4] (E = CPh3, [2][BF4]; E = H, [3][BF4]), in ca. 85% yield. The molecular structure of ([2][BF4]) was ascertained by X-ray diffractometry; X-ray, NMR and DFT results agreed in that one single isomer formed, bearing the [CH2CPh3] group pointing far from the Fe-Fe axis. The reaction of [3][BF4] with NHEt2 in the presence of PhSSPh resulted in the prevalent formation of [FeCp(CO)(2)SPh] (7). (C) 2013 Elsevier B.V. All rights reserved.