Aromatic C−H Bond Activation of 2-Methylpyridine Promoted by an Osmium(VI) Complex: Formation of an η2(N,C)-Pyridyl Derivative

Abstract

The complex OsH6(PiPr3)2 (1) activates the NC-H bond of 2-mediylpyridine to afford the η2(C,N) pyridyl derivative OsH3 {η2(C,N)-[NC 5H3Me]}(PiPr3)2 (2), which in dichloromemane undergoes the selective chlorination of one of the hydride ligands to give OsH2Cl{η2(C,N)-[NC 5H3Me] }(PiPr3)2 (4). In solution the hydride ligands of 2 exchange their positions through two different processes, which have been analyzed by 1H NMR spectroscopy and DFT calculations. The X-ray structures of 2 and 4 are also reported. © 2008 American Chemical Society.