Stepwise MetalLigand Cooperation by a Reversible Aromatization/Deconjugation Sequence in Ruthenium Complexes with a Tetradentate Phenanthroline-Based Ligand

作者：Langer Robert; Fuchs Ido; Vogt Matthias; Balaraman Ekambaram; Diskin Posner Yael; Shimon Linda J W; Ben David Yehoshoa; Milstein David^*

来源：Chemistry - A European Journal, 2013, 19(10): 3407-3414.

DOI：10.1002/chem.201204003

• cooperative effects
• coordination chemistry
• dehydrogenation
• homogeneous catalysis
• ruthenium

The synthesis and reactivity of ruthenium complexes containing the tetradentate phenanthroline-based phosphine ligand 2,9-bis((di-tert-butylphosphino)methyl)-1,10-phenanthroline (PPhenP) is described. The hydrido chloro complex [RuHCl(PPhenP)] (2) undergoes facile dearomatization upon deprotonation of the benzylic position, to give [RuH(PPhenP-H)] (4). Addition of dihydrogen to 4 causes rearomatization of the phenanthroline moiety to trans-[Ru(H)2(PPhenP)] (5), followed by hydrogenation of an aromatic heterocycle in the ligand backbone, to give a new dearomatized and deconjugated complex [RuH(PPhenP*-H)] (6). These aromatization/deconjugation steps of the coordinated ligand were demonstrated to be reversible and operative in the dehydrogenation of primary alcohols without the need for a hydrogen acceptor. This aromatization/deconjugation sequence constitutes an unprecedented mode of a stepwise cooperation between the metal center and the coordinated ligand.

• 出版日期2013-3