194020-92-3Relevant articles and documents
Mono- and bicyclic organometallic ring systems with exocyclic C=C and C=S bonds
Werner, Helmut,Xiaolan, Liu,Peters, Karl,Von Schnering, Hans Georg
, p. 871 - 877 (1997)
The cobaltaheterocycles [C5H5Co{κ2(C,S)-C(=CH 2)-N(R)C(=S)S)(PMe2Ph)] (5-7), which contain both an exocyclic C=C and C=S bond, were prepared from the iminoacylcobalt compounds [C5H5Co|C(CH3)=NCH3)(PMe 2Ph)]I (2-4) on treatment with either CS2/NaOCH3 or K[S2CNMe2], respectively. While protonation of 5 (R = CH3) and 7 (R = CH2Ph) with HBF4 occurs at the exocyclic C=CH2 bond to give cations containing a CoC(CH3)N(R)C(=S)S ring, the methylation of 5 and 7 with [OMe3]BF4 takes place at the exocyclic C=S bond and generates five-membered heterocycles with an SCH3 substituent. The reaction of 5-7 with S8 leads to the elimination of the phosphane ligand and affords the bicyclic dithiolenecobalt complexes 14 -16 in moderate to good yields. On treatment of 5-7 with C2(CO2R′)2 (R′ = Me, Et), an insertion of the alkyne into the C=CH2 bond occurs and five-membered ring systems 19-22 with an unsaturated exocyclic =C(CO2R′)-C(CO2R′)=CH2 group are formed. As in the case of 5 and 7, protonation and methylation reactions of 19 also take place at different sites leading to cations with either a delocalized CoCN or NCS unit. Keywords: Cobalt / Cyclopentadienyl complexes / Heterocycles / Electrophilic addition / Insertion reaction VCH Verlagsgescllschaft mbH.
