title: Synthesis and Reactivity of a Bio-inspired Dithiolene Ligand and its Mo Oxo Complex.
abstract: An original synthesis of the fused pyranoquinoxaline dithiolene ligand qpdt(2-) is discussed in detail. The most intriguing step is the introduction of the dithiolene moiety by Pd-catalyzed carbon-sulfur coupling. The corresponding Mo(IV)O complex (Bu4N)2 [MoO(qpdt)2] (2) underwent reversible protonation in a strongly acidic medium and remained stable under anaerobic conditions. Besides, 2 was found to be very sensitive towards oxygen, as upon oxidation it formed a planar dithiin derivative. Moreover, the qpdt(2-) ligand in the presence of [MoCl4 (tBuNC)2] formed a tetracyclic structure. The products resulting from the unique reactivity of qpdt(2-) were characterized by X-ray diffraction, mass spectrometry, NMR spectroscopy, UV/Vis spectroscopy, and electrochemistry. Plausible mechanisms for the formation of these products are also proposed.
authors.affiliation: Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231, Paris CEDEX 05, France.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Porcher
authors.affiliation: Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231, Paris CEDEX 05, France.
authors.forename: Thibault
authors.initials: T
authors.lastname: Fogeron
authors.affiliation: Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231, Paris CEDEX 05, France.
authors.forename: Maria
authors.initials: M
authors.lastname: Gomez-Mingot
authors.affiliation: Sorbonne Universités, UPMC Université Paris 6, Institut Parisien de Chimie Moléculaire, UMR 8232 CNRS, 4 Place Jussieu, 75252, Paris CEDEX 05, France.
authors.forename: Lise-Marie
authors.initials: LM
authors.lastname: Chamoreau
authors.affiliation: Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231, Paris CEDEX 05, France. yun.xu-li@college-de-france.fr.
authors.forename: Yun
authors.initials: Y
authors.lastname: Li
authors.affiliation: Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231, Paris CEDEX 05, France. marc.fontecave@college-de-france.fr.
authors.forename: Marc
authors.initials: M
authors.lastname: Fontecave
mesh_terms: D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D008982:Molybdenum / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D011083:Polycyclic Compounds / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D008024:Ligands; D009942:Organometallic Compounds; D011083:Polycyclic Compounds; D008982:Molybdenum
keywords: cross-coupling; dithiolene ligands; molybdenum; protonation; sulfur heterocycles