Mild selective metathesis of alkane C–H bonds and C–X bonds of polyhalogenomethane CH4–nXn (X = Cl, n = 4; Br, I, n = 3) catalysed with chlorotris(triphenylphosphine)rhodium(I)

Alkanes RH (n-C₆H₁₄, cyclo-C₆H₁₂) and toluene react with polyhalogenomethanes CC1₄, CHBr₃ and CHI₃ at 80–110 °C under catalysis with Wilkinson's complex, RhCl(PPh₃)₃, to produce halogenohydrocarbons RX and CHC1₃, CH₂Br₂ or CH₂I₂ respectively with unusually high selectivity which decreases in the order: C–H_secondary > > C–H_benzyiic > C–H_primary.