J. CHEM. SOC., CHEM. COMMUN., 1987 971 Intramolecular, Reversible C-H Oxidative Addition-Reductive Elimination at Rhodium. Reaction of the Intermediate with Different Types of C-H Bonds and Dihydrogen Claudio Bianchini, Andrea Meli, Maurizio Peruzzini, and Fabrizio Zanobini lstituto per lo Studio della Stereochimica ed Energetica dei Composti di Coordinazione, C. N. R., Via J. Nardi, 39, Firenze 50 132, ltal y The ortho-metallated complex [{ (Ph2PCH2CH2)2N(CH2CH2PPhC6H4)}RhH](S03CF3) thermally or chemically undergoes reductive elimination of the substituted phenyl group; the N(CH2CH2PPh2)J3h+ fragment thus formed is stabilized by CO, halides, C2H4, or engaged in oxidative additions of H2 and C-H bonds from arenes, alkynes, and aldehydes. Some examples of transition metal complexes capable of inserting into hydrocarbon C-H bonds have recently appeared in the literature.' In most instances, these metal systems contain as ancillary ligands pentamethylcyclopentadienyl, carbonyls, and/or trialkylphosphines, but polyphosphane tripod-like ligands are also quite efficient.2.3 One of these is the potentially tetradentate hybrid ligand N(CH2CH2PPh2)3, denoted np3. The fragment (np3)Ir+ generated by C1- elimination from (np3)IrC1 in tetrahydrofuran (THF) , undergoes straight- forward oxidative addition of a C-H bond from different alkenes, to give cis-hydrido(malkeny1) derivatives, equation (1).2 These are quite stable, probably because of the kinetic inertness of iridium complexes. Since substitution of rhodium for iridium in many reactions gives analogous products but with considerably less stab- Published on 01 January 1987. Downloaded by Harbin Institute of Technology on 27/05/2013 13:06:45. View Article Online / Journal Homepage / Table of Contents for this issue