PtII-Catalyzed Hydrophenylation of α-Olefins: Variation of Linear/Branched Products as a Function of Ligand Donor Ability
摘要:
The Pt-II complexes [((x)bpy)Pt(Ph)(THF)(+) ((x)bpy = 4,4'-X-2-2,2'-bipyridyl; x = OMe (la), Bu-t (lb), H (lc), Br (1d), CO2Et (le) and NO2 (10] catalyze the formation of n-propylbenzene and cumene from benzene and propene. The catalysts are selective for branched products, and the cumene/n-propylbenzene ratio decreases with increasing donor ability of the (x)bpy ligand. DFT(D) calculations predict more favorable activation barriers for 1,2-insertion into the Pt Ph bond to give branched products. The calculations indicate that 1,2-insertion of propene should be faster than 2,1-insertion for all Pt(II) catalysts studied, but they also indicate that cumene/n-propylbenzene selectivity is under Curtin Hammett control.
Hydroarylation of Unactivated Olefins Catalyzed by Platinum(II) Complexes
作者:Bradley A. McKeown、Nicholas A. Foley、John P. Lee、T. Brent Gunnoe
DOI:10.1021/om8006008
日期:2008.8.1
The Pt(II) complex [(tbpy)Pt(Ph)(THF)][BAr′4] catalyzes the hydroarylation of olefins utilizing unactivated substrates. Preliminary studies indicate that the reactions proceed via Pt-mediated C−H activation rather than a traditional Friedel−Crafts pathway.