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

• Published in: Inorganica Chimica Acta 2012-01, Vol.380, p.96-103
• Main Authors: Nair, Radhika P., Pineda-Lanorio, Jocelyn A., Frost, Brian J.
• Format: Article
• Language: English
• Subjects: Addition to olefin; Atom transfer radical addition (ATRA); Carbon tetrachloride; Chlorinated ester; Ruthenium(II) catalyst
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2011.11.008

Ruthenium complexes of the type Cp∗Ru(PPh3)(PR3)Cl (PR3=PTA, PPh3, or PMe3) efficiently catalyzed the atom transfer radical addition of chlorinated esters across styrene and that of carbon tetrachloride across a variety of olefins, affording the adducts in good to excellent yields at 60–85°C. [Display omitted] ► Cp′Ru(PPh3)(PR3)Cl catalyzed atom transfer radical addition (ATRA). ► Highly active catalysts for ATRA. ► Addition of CCl4 and chlorinated esters to olefins. ► Addition of CCl4 to stilbene and chalcone. 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.