Stille Cross-Coupling Reaction with Cationic [(η5-Cp)(η6-C6H6–xIx)Ru]+ Complexes as Key for Ethynyl-Bridged Homo- and Heteronuclear Sandwich Compounds
摘要:
The cationic homo- and heteronuclear sandwich complexes (eta(5)-cyclopentadienyl)(ferrocenylethynyl-eta(6)-benzene)ruthenium(II) hexafluoridophosphate (3a), (eta(5)-cyclopentadienyl)(ruthenocenylethynyl-eta(6)-benzene)ruthenium(II) hexafluoridophosphate (3b), (eta(5)-cyclopentadienyl)[1,4-bis(ferrocenylethynyl)-eta(6)-benzene]ruthenium(II) hexafluoridophosphate (4a), (eta(5)-cyclopentadienyl)[1,4-bis(ruthenocenylethynyl)-eta(6)-benzene]ruthenium(II) hexafluoridophosphate (4b), and (eta(5)-cyclopentadienyl)[1,3,5-tris(ferrocenylethynyl)-eta(6)-benzene]ruthenium(II) hexafluoridophosphate (5) were synthesized by means of Stille cross-coupling reaction using tri-n-butyl(metallocenylethynyl)stannane as nucleophile and the appropriate (eta(5)-cyclopentadienyl)(eta(6)-iodobenzene)ruthenium(II) cations as electrophiles. As a catalyst, a Pd(0) complex, furnished with AsPh3 ligands, was applied. The hitherto unknown iodobenzene complexes (eta(5)-cyclopentadienyl)(1,4-eta(6)-diiodobenzene)ruthenium(II) hexafluoridophosphate (1b) and (eta(5)-cyclopentadienyl)(eta(6)-1,3,5-triiodobenzene)ruthenium(II) hexafluoridophosphate (1c) as well as the described cationic homo- and heteronuclear sandwich complexes 3-5 were fully characterized and investigated with respect to the second-harmonic generation by hyper-Rayleigh scattering. For complexes 1b, 1c, 3a, and 5 X-ray structure determinations were performed.
Towards the synthesis of amino[b,e][1,4]dioxin derivatives via cationic ruthenium complexes
摘要:
Double nucleophilic aromatic substitution reactions between N-substituted (eta(6)-1,2-dichlorobenzene)RuCp(+) salts and substituted 1,2-benzenediols have been carried out under mild conditions to prepare N-substituted (eta(6)-dibenzo[b,e][1,4]dioxin)ruthenium(II) complexes. The dibenzodioxin ligands were subsequently liberated by photolysis, with radiation from a sunlamp or from a medium pressure Hg lamp (300 nm).