Tandem deoxygenative hydrosilation of carbon dioxide with a cationic scandium hydridoborate and B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>
作者:Daniel W. Beh、Warren E. Piers、Benjamin S. Gelfand、Jian-Bin Lin
DOI:10.1039/c9dt04323c
日期:——
A scandium hydridoborate complex supported by the dianionic pentadentate ligand B2Pz4Py is prepared via hydride abstraction from the previously reported scandium hydride complex with tris-pentafluorophenyl borane.
Competitive Aryl–Fluorine and Aryl–Halogen (Halogen = Cl, Br) Bond Cleavage with Iridium Porphyrin Complexes
作者:Ying Ying Qian、Bao Zhu Li、Kin Shing Chan
DOI:10.1021/om301196t
日期:2013.3.25
Base-promoted competitive Ar-F and Ar-X (X = Cl, Br) bond cleavage with iridium porphyrin complexes was investigated. Mechanistic studies suggested that Ir(ttp)(-) (ttp = 5,10,15,20-tetra-p-tolylporphyrinato dianion) cleaves the Ar-F bond via nucleophilic aromatic substitution and Ir-2(ttp)(2) cleaves the Ar-X (X = Cl, Br) bond via metalloradical ipso substitution. Therefore, a stronger base, polar solvent, lower temperature, and iridium anion precursor favor Ar-F bond cleavage, while a weaker base, nonpolar solvent, higher temperature, and Ir-2(ttp)(2) precursor favor Ar-X (X = Cl, Br) bond cleavage.