title: Carboxylation of an ansa-zirconocene dinitrogen complex: regiospecific hydrazine synthesis from N2 and CO2.
abstract: Addition of 2 equiv of carbon dioxide to the ansa-zirconocene dinitrogen complex resulted in selective insertion into each zirconium nitrogen bond, forming a C2 symmetric dicarboxylated diazenido compound. Treatment with excess Me3SiI furnished the ansa-zirconocene diiodide along with the N,N'-dicarboxylated silylated hydrazine. New nitrogen-carbon bonds were also assembled by addition of methyl triflate. Tri- and tetrasubstituted hydrazines could be formed by treatment with water and Me3SiI, respectively. The regiochemistry of the N2 carboxylation is controlled by the ansa-cyclopentadienyl ligand where the sterically demanding tert-butyl substituents and the C2 symmetry of the dimer dictates the stereochemistry of CO2 insertion. These results demonstrate the ability of zirconium dinitrogen compounds to participate in heterocumulene insertion chemistry.
authors.affiliation: Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, USA.
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Knobloch
authors.forename: Hannah E
authors.initials: HE
authors.lastname: Toomey
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Chirik
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D006834:Hydrazines / Q000138:chemical synthesis* / Q000737:chemistry; D008024:Ligands; D008968:Molecular Conformation; D009584:Nitrogen / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D013237:Stereoisomerism; D015040:Zirconium / Q000737:chemistry*
chemical_list: D002264:Carboxylic Acids; D006834:Hydrazines; D008024:Ligands; D009942:Organometallic Compounds; C023398:Zirconocene dichloride; D002245:Carbon Dioxide; D015040:Zirconium; D009584:Nitrogen