title: Stable N-heterocyclic carbene (NHC)-palladium(0) complexes as active catalysts for olefin cyclopropanation reactions with ethyl diazoacetate.
abstract: The Pd(0) complexes [(NHC)PdL(n)] (NHC=N-heterocyclic carbene ligand; L=styrene for n=2 or PR(3) for n=1) efficiently catalyse olefin cyclopropanation by using ethyl diazoacetate (EDA) as the carbene source with activities that improve on previously described catalytic systems based on this metal. Mechanistic studies have shown that all of these catalyst precursors deliver the same catalytic species in solution, that is, [(IPr)Pd(sty)], a 14e(-) unsaturated intermediate that further reacts with EDA to afford [(IPr)Pd(=CHCO(2)Et)(sty)], from which the cyclopropane is formed.
authors.affiliation: Laboratorio de Catálisis Homogénea, Departamento de Química y Ciencia de los Materiales, Unidad Asociada al CSIC, Centro de Investigación en Química Sostenible (CIQSO), Campus de El Carmen s/n, Universidad de Huelva, 21007-Huelva, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Martín
authors.forename: Francisco
authors.initials: F
authors.lastname: Molina
authors.forename: Eleuterio
authors.initials: E
authors.lastname: Alvarez
authors.forename: Tomás R
authors.initials: TR
authors.lastname: Belderrain
mesh_terms: D002384:Catalysis; D018360:Crystallography, X-Ray; D003979:Diazonium Compounds / Q000737:chemistry*; D006571:Heterocyclic Compounds / Q000737:chemistry*; D008024:Ligands; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D003979:Diazonium Compounds; D006571:Heterocyclic Compounds; D008024:Ligands; D009942:Organometallic Compounds; C030011:carbene; D010165:Palladium; C032111:diazoacetic ester; D008697:Methane