Reactions of an Osmium Bis(dihydrogen) Complex under Ethylene: Phosphine Addition to a C–C Double Bond and C–H Bond Activation of Fluoroarenes

The bis­(dihydrogen) complex [OsTp­(η2-H2)2(PiPr3)]­BF4 (1; Tp = hydridotris­(pyrazolyl)­borate) reacts with
ethylene
under 2 atm of the gas to afford [OsTp­(CH2CH2PiPr3)­(η2-CH2CH2)2]­BF4 (2), which promotes
the CH bond activation of fluorobenzene and 1,3-difluorobenzene to
give OsTp­(3-C6H4F)­(η2-CH2CH2)2 (3) and OsTp­(3,5-C6H3F2)­(η2-CH2CH2)2 (4), respectively,
releasing [EtPiPr3]­BF4. The formation
of 2 takes place via [OsTp­(η2-CH2CH2)2(PiPr3)]­BF4 (5), which has been isolated and characterized
by X-ray diffraction analysis.