title: NHC-manganese(i) complexes as carbene transfer agents.
abstract: Tautomerization of coordinated azoles to their corresponding N-heterocyclic carbenes (NHCs) has been carried out by reaction of complexes fac-[Mn(L)(CO)(3)(dppe)](+) (L = N-phenylimidazole) and fac-[Mn(L)(CO)(3)(bipy)](+) (L = N-methylbenzimidazole, benzoxazole, benzothiazole) with KO(t)Bu and subsequent protonation of the azolyl intermediates with NH(4)PF(6). Several NHC-manganese(i) complexes bearing an N-H residue of general formula fac-[Mn(NHC)(CO)(3)(dppe)](+) and fac-[Mn(NHC)(CO)(3)(bipy)](+) have been tested as carbene transfer agents to the gold fragments [Au(L)](+) (L = PPh(3), CNPh, CNXylyl), allowing isolation or spectroscopic detection of various Mn(i)/Au(i) heterometallic intermediates containing azolyl bridging ligands, which liberate the gold(i) carbene complexes [Au(NHC)(L)](+) by means of acid hydrolysis. By contrast, when using the silver(i) fragment [Ag(PPh(3))](+) as carbene acceptor no transmetallation process occurred but instead inverse tautomerization of the NHC to the corresponding imidazole ligand was observed.
authors.affiliation: Departamento de Química Orgánica e Inorgánica, Facultad de Química, Universidad de Oviedo, 33006, Oviedo, Spain. jruiz@uniovi.es
authors.forename: Javier
authors.initials: J
authors.lastname: Ruiz
authors.forename: Angela
authors.initials: A
authors.lastname: Berros
authors.forename: Bernabé F
authors.initials: BF
authors.lastname: Perandones
authors.forename: Marilín
authors.initials: M
authors.lastname: Vivanco
mesh_terms: D018360:Crystallography, X-Ray; D006046:Gold / Q000737:chemistry; D006571:Heterocyclic Compounds / Q000737:chemistry*; D008024:Ligands; D008345:Manganese / Q000737:chemistry*; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D012834:Silver / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D006571:Heterocyclic Compounds; D008024:Ligands; D009942:Organometallic Compounds; C030011:carbene; D012834:Silver; D008345:Manganese; D006046:Gold; D008697:Methane