566173-52-2Relevant academic research and scientific papers
Intramolecular C-H activation by dicationic Pt(II) complexes
Wong-Foy, Antek G.,Henling, Lawrence M.,Day, Mike,Labinger, Jay A.,Bercaw, John E.
, p. 3 - 16 (2008/10/08)
The dicationic complexes [(ArN=C(Me)-C(Me)=NAr)Pt(solv)2]X2, (Ar = 2,6-(CH3)2C6H3; 5a: solv = CH3CN, X = CF3SO3-, BF4-, SbF6-; 5b: solv = (CH3)2CO, X = BF4-, SbF6-) and [(CyN=C(H)-C(H)=NCy)Pt(CH3CN)2]X2, (Cy = C6H11, 6: X = OTf-, BF4-, PF6-, SbF6-) were synthesized from the corresponding Pt dichlorides with two equivalents of AgX. The reactions of 5a with 1-phenylpyrazole, 2-phenylpyridine, 2-vinylpyridine, and 2-(2-thienyl)pyridine afford the cyclometalated products 11-14 via intramolecular C-H activation of an sp2 C-H bond of the unsaturated sidegroup. Pyridines with saturated groups at the 2-position do not undergo a similar cyclometalation reaction. In trifluoroethanol-d3 solution, 6 undergoes cyclometalation of one of the cyclohexyl groups, an example of sp3 C-H bond activation. The latter reaction proceeds only partway to completion, implying that an equilibrium has been reached; in the case where X = OTf--the equilibrium favors the starting dication.
