Double C−H Activation on Osmium and Ruthenium Centers: Carbene vs Olefin Products

Cyclometalation of bis(di- tert -butylphosphino)pentane (D t BPP) and subsequent product dehydrogenation take place in reactions of D t BPP with [OsCl 6 ] 2 - and [RuCl 2 ( p -cymene)] 2 to give the M(IV) dihydrides, MH 2 Cl[CH(C 2 H 4 PBu t 2 ) 2 ], and the (alkylidene)osmium and (olefin)ruthenium complexes OsHCl[ C(C 2 H 4 PBu t 2 ) 2 ] and RuHCl[Bu t 2 PCH 2 CH 2 (( E )-CH CH)CH 2 PBu t 2 ].