Addition of N-Heterocyclic Carbenes to a Ruthenium(VI) Nitrido Polyoxometalate: a New Route to Cyclic Guanidines

• Published in: Inorganic chemistry 2011-03, Vol.50 (6), p.2501-2506
• Main Authors: Besson, Claire, Mirebeau, Jean-Hugues, Renaudineau, Séverine, Roland, Sylvain, Blanchard, Sébastien, Vezin, Hervé, Courillon, Christine, Proust, Anna
• Format: Article
• Language: English
• Subjects: Chemical Sciences; Guanidines - chemistry; Heterocyclic Compounds - chemistry; Material chemistry; Methane - analogs & derivatives; Methane - chemistry; Molecular Structure; or physical chemistry; Organometallic Compounds - chemical synthesis; Organometallic Compounds - chemistry; Ruthenium - chemistry; Silver - chemistry; Theoretical and; Tungsten - chemistry
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/ic102307w

The scope of N-atom transfer from the electrophilic ruthenium(VI) nitrido containing polyoxometalate [PW11O39RuVIN]4− has been extended to the N-heterocyclic carbene {CH2(Mes)N}2C and the coupling product {CH2(Mes)N}2CNH2 + characterized by 1H NMR and high-resolution mass spectrometry. Because guanidines display many fields of applications ranging from biology to supramolecular chemistry, this could afford an original route to the synthesis of cyclic guanidines. This also enlarges the potential of nitrido complexes in the synthesis of heterocycles, mainly illustrated in the literature through the formation of aziridines through N-atom transfer to alkenes. In the course of the reaction, the ruthenium(III)-containing polyoxometallic intermediate [PW11O39RuIII{NC{N(Mes)CH2}2}]5− has been thoroughly characterized by continuous-wave and pulsed electron paramagnetic resonance, which nicely confirms the presence of the organic moiety on the polyoxometallic framework, Ru K-edge X-ray absorption near-edge structure, and electrochemistry.