[(tBu2PCH2SiMe2)2N]RhI?: Rapidly reversible H-C(sp3) and H-C(sp2) bond cleavage by rhodium(I)

The product of the reaction of ((Bu2PCH2SiMe2)-Bu-t)(2)N- (MgCl+ salt) with [RhCl(cyclooctene)(2)](2) is a Rh-III complex where one Bu-t methyl C-H bond has oxidatively added to Rh: (PNP*)RhH. This is in rapid exchange among all 9 x 4 C-H bonds of the four Bu-t groups. (PNP*)RhH undergoes oxidative addition equilibrium with the C-H bonds of benzene at similar to 10(3) S-I at 25 degrees C and oxidatively adds the ring C-H of other arenes. (PNP*)RhH forms eta(2)-olefin complexes with several olefins and dehydrogenates allylic C-H bonds to form (PNP)Rh(H)(2).