Atom transfer radical addition (ATRA) of carbon tetrachloride and chlorinated esters to various olefins catalyzed by Cp′Ru(PPh3)(PR3)Cl complexes

Cp∗Ru(PPh3)(PR3)Cl complexes, where PR3 = PMe3, PPh3, or PTA (PTA = 1,3,5-triaza-7-phosphaadamantane), were used to catalyze the atom transfer radical addition of chlorinated esters (CCl3CO2Et, CH2ClCO2Et) to styrene, and that of CCl4 to a variety of olefins. The monoadducts were obtained in moderate to excellent yields. Moreover, high selectivities were obtained for the addition of CCl4 to internal olefins. The activity of Cp∗Ru(PTA)(PPh3)Cl and Cp∗Ru(PTA)(PMe3)Cl were comparable to that of the highly efficient ATRA catalyst, Cp∗Ru(PPh3)2Cl. The addition of CCl3CO2Et to styrene catalyzed by Cp′Ru(PPh3)(PR3)Cl (Cp′ = Dp, Ind, Cp, Tp) are also reported here. Two new compounds, 3-chloro-3-phenyl-2-(trichloromethyl)-1-phenylpropan-1-one and 1,3,3,3-tetrachloro-1,2-diphenylpropane, resulting from the addition of CCl4 to chalcone and cis-stilbene have been isolated and characterized by NMR spectroscopy and X-ray crystallography.