Ruthenium Phosphine/Diimine Complexes: Syntheses, Characterization, Reactivity with Carbon Monoxide, and Catalytic Hydrogenation of Ketones
作者:Márcio P. de Araujo、Alberthmeiry T. de Figueiredo、André L. Bogado、Gustavo Von Poelhsitz、Javier Ellena、Eduardo E. Castellano、Claudio L. Donnici、João V. Comasseto、Alzir A. Batista
DOI:10.1021/om050182b
日期:2005.12.1
The cis-[RuCl2(PPh3)(2)(N-N)] (N-N = bipy (1), Me-bipy (2), phen (3), and bathophen (4)) complexes were used to synthesize five new electron-rich phosphine-containing complexes cis- [RuCl2(dcype)(N-N)] (N-N = bipy (1a), Me-bipy (2a), phen (3a), and bathophen (4a)) and cis- [RuCl2(PEt3)(2)(bipy)] (1c) by phosphine exchange. These complexes were obtained and characterized by NMR (P-31H-1}, H-1), cyclic voltammetry, and elemental analysis. Electrochemical studies of these complexes reveal a single reduction process (Ru-III/Ru-II). These complexes are more easily oxidized than their analogues cis-[RuCl2(dppb)(N-N)]. The reactivity of complexes cis-[RuCl2(dcype)(N-N)] with carbon monoxide was tested, and dissociation of one chloride was observed, leading to the formation of four new cationic species with general formula [RuCl(CO)(dcype)(N-N)](PF6) (bipy (1b), Me-bipy (2b), phen (3b), and bathophen (4b)). The complexes described here and elsewhere with general formulas cis-[RuCl2(P-P)(N-N)], [RuCl(CO)(dcype)(N-N)] (PF6) and cis-[RuCl2(P)(2)(N-N)] were used as precatalysts in the transfer hydrogenation of functionalized aryl-ketones, and most of them were active. X-ray structures of cis- [RuCl2(PEt3)(2)(bipy)] (1c) and [RuCl(CO)(dcype)(bipy)](PF6) (1b) will be presented.