SYNTHESIS AND NUCLEOPHILIC-SUBSTITUTION OF HIGHLY CHLORINATED ARENE (ETA(5)-PENTAMETHYLCYCLOPENTADIENYL)RUTHENIUM PI-COMPLEXES

Facile synthesis of Cp*Ru+ (Cp* = pentamethylcyclopentadienyl) pi-complexes of highly electron deficient aromatics, including 1,3,5-trichloro-, 1,2,4,5-tetrachloro-, pentachloro-, and hexachlorobenzene, is accomplished by the ligand exchange reaction with Cp*Ru(CH3CN)(3)(+)-SO3CF3- in polar solvents under mild reaction conditions. The extraordinary activating ability of the Cp*Ru+ moiety is demonstrated by rapid and quantitative nucleophilic substitution reactions of the 1,3,5-tri- and 1,2,4,5-tetrachlorobenzene pi-complexes with potassium phenoxide, thiophenoxide, 4-aminophenoxide, 4-chlorophenoxide, and 4-fluorophenoxide. This methodology allows syntheses of highly substituted and functionalized aromatic compounds.