title: Rollover-assisted C(sp2)-C(sp3) bond formation.
abstract: Rollover cyclometalation involves bidentate heterocyclic donors, unusually acting as cyclometalated ligands. The resulting products, possessing a free donor atom, react differently from the classical cyclometalated complexes. Taking advantage of a "rollover"/"retro-rollover" reaction sequence, a succession of oxidative addition and reductive elimination in a series of platinum(II) complexes [Pt(N,C)(Me)(PR3)] resulted in a rare C(sp(2))-C(sp(3)) bond formation to give the bidentate nitrogen ligands 3-methyl-2,2'-bipyridine, 3,6-dimethyl-2,2'-bipyridine, and 3-methyl-2-(2'-pyridyl)-quinoline, which were isolated and characterized. The nature of the phosphane PR3 is essential to the outcome of the reaction. This route constitutes a new method for the activation and functionalization of C-H bond in the C(3) position of bidentate heterocyclic compounds, a position usually difficult to functionalize.
authors.affiliation: Dipartimento di Chimica e Farmacia, Università degli Studi di Sassari, Via Vienna 2, 07100 Sassari (Italy). zucca@uniss.it.
authors.forename: Antonio
authors.initials: A
authors.lastname: Zucca
authors.forename: Luca
authors.initials: L
authors.lastname: Maidich
authors.forename: Laura
authors.initials: L
authors.lastname: Canu
authors.forename: Giacomo L
authors.initials: GL
authors.lastname: Petretto
authors.forename: Sergio
authors.initials: S
authors.lastname: Stoccoro
authors.forename: Maria Agostina
authors.initials: MA
authors.lastname: Cinellu
authors.forename: Guy J
authors.initials: GJ
authors.lastname: Clarkson
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Rourke
keywords: NMR spectroscopy; bond coupling; platinum; reductive elimination; rollover cyclometalation