Catalytic Hydroarylation of Ethylene Using TpRu(L)(NCMe)Ph (L = 2,6,7-Trioxa-1-phosphabicyclo[2,2,1]heptane): Comparison to TpRu(L′)(NCMe)Ph Systems (L′ = CO, PMe<sub>3</sub>, P(pyr)<sub>3</sub>, or P(OCH<sub>2</sub>)<sub>3</sub>CEt)
收藏资源简介：
The Ru(II) complex TpRu[P(OCH2)2(OCCH3)](NCMe)Ph (4; Tp = hydridotris(pyrazolyl)borate) has been synthesized and isolated. At 90 °C, TpRu[P(OCH2)2OCCH3](NCMe)Ph in C6D6 produces TpRu[P(OCH2)2(OCCH3)](NCMe)Ph-d5 and C6H5D. TpRu[P(OCH2)2(OCCH3)](NCMe)Ph catalyzes the hydrophenylation of ethylene at 90 °C to produce ethylbenzene with 90 turnovers (TOs) after 50 h. Catalyst deactivation occurs by the formation of the η3-allyl complex TpRu[P(OCH2)2(OCCH3)](η3-C3H4Me). Kinetic studies of stoichiometric C6D6 activation by TpRu(L)(NCMe)Ph (L = CO, P(OCH2)3CEt, PMe3 P(OCH2)2(OCCH3)) to give TpRu(L)(NCMe)Ph-d5 and C6H5D reveal that the reactions occur with the following relative rates: PMe3 (kobs = [1.36(4)] × 10–5 s–1) > P(OCH2)3CEt (kobs = 1.20(2) × 10–5 s–1) > P(OCH2)2(OCCH3)(kobs = 7.2(5) × 10–6 s–1) > CO (kobs = [4.62(3)] × 10–6 s–1). These rates correlate linearly with Ru(III/II) potentials of the four TpRu(L)(NCMe)Ph complexes. DFT calculations have been used to model catalytic olefin hydroarylation by TpRu[P(OCH2)2(OCCH3)](NCMe)Ph (4) and to rationalize the observed differences in the various TpRu(L)(NCMe)Ph catalysts.
