ABSTRACT
Treatment of the 2,5-bis(2'-pyridyl)pyrrolato (PDP-) anion with {Ru(COD)Cl2}n in THF readily yielded [Ru(PDP)(COD)Cl] (1) in almost quantitative yield. Anion metathesis of 1 in organic solvent by NO3- and OTf- (OTf- = triflato) gave [Ru(PDP)(COD)(NO3)] (2) and [Ru(PDP)(COD)(OTf)] (3), and in aqueous solution by BF4- and PF6- afforded aqueous complexes [Ru(PDP)(COD)(H2O)](BF4) (4+·BF4-) and [Ru(PDP)(COD)(H2O)](PF6) (4+·PF6-), respectively. Treatment of 1 with PhICl2 in CH2Cl2 afforded 5 with halogenated pyrrole. These complexes exhibit similar structure, including one Ru(ii) atom, one 2,5-bis(2'-pyridyl)pyrrole and one monodentate anion or aqua ligand. Each Ru(ii) tightly binds to three adjacent coplanar sites of PDP- ligand to form a meridional configuration. Complex 1 with NaIO4 as the oxidant in EtOAc-CH3CN-H2O (ratio = 3 : 1 : 2) proved to be highly effective in the catalytic oxidation of olefins to carbonyl products.
