| Autor: |
Ju L; Department of Chemistry, New York University, 100 Washington Square East, New York, New York 10003, United States., Lin Q; Department of Chemistry, New York University, 100 Washington Square East, New York, New York 10003, United States., LiBretto NJ; Department of Chemical Engineering, Purdue University, 480 Stadium Mall Drive, West Lafayette, Indiana 47906, United States., Wagner CL; Department of Chemistry, New York University, 100 Washington Square East, New York, New York 10003, United States., Hu CT; Department of Chemistry, New York University, 100 Washington Square East, New York, New York 10003, United States., Miller JT; Department of Chemical Engineering, Purdue University, 480 Stadium Mall Drive, West Lafayette, Indiana 47906, United States., Diao T; Department of Chemistry, New York University, 100 Washington Square East, New York, New York 10003, United States. |
| Abstrakt: |
Bi-Oxazoline (biOx) has emerged as an effective ligand framework for promoting nickel-catalyzed cross-coupling, cross-electrophile coupling, and photoredox-nickel dual catalytic reactions. This report fills the knowledge gap of the organometallic reactivity of (biOx)Ni complexes, including catalyst reduction, oxidative electrophile activation, radical capture, and reductive elimination. The biOx ligand displays no redox activity in (biOx)Ni(I) complexes, in contrast to other chelating imine and oxazoline ligands. The lack of ligand redox activity results in more negative reduction potentials of (biOx)Ni(II) complexes and accounts for the inability of zinc and manganese to reduce (biOx)Ni(II) species. On the basis of these results, we revise the formerly proposed "sequential reduction" mechanism of a (biOx)Ni-catalyzed cross-electrophile coupling reaction by excluding catalyst reduction steps. |
