Substituent Effects on Stoichiometric and Catalytic Cleavage of Carbon–Nitrogen Bonds in Aniline Derivatives by Ruthenium–Phosphine Complexes

The reactivity of various o -acylaniline derivatives with ruthenium complexes was examined. The reaction of o -acylanilines with RuH 2 (CO)(PPh 3 ) 3 ( 1 ) or an activated ruthenium species formulated as “Ru(CO)(PPh 3 ) 3 ” ( 4 ) gave amido hydrido complexes 3 and aryl amido complexes 6 formed via N–H and C–N bond cleavage, respectively. Addition of olefins, such as vinylsilanes, accelerates the C–N bond cleavage. The aryl amido complexes 6 can provide the C–N arylation product upon treatment with arylboronates. The relative reactivity of o -acylanilines bearing various substituents was investigated by competition experiments, and it was found that electron-donating substituents increase the relative facileness of the C–N bond cleavage in both stoichiometric and catalytic reactions. The trend observed here is different from the one observed for the previously reported tantalum-mediated C–N bond cleavage.