Abstract
The organonickel complexes [Ni(Phbpy)X] (X = Br, OAc, CN) were obtained for the first time in a direct base-assisted arene C(sp2)-H cyclometalation reaction from the rather unreactive precursor materials NiX2 and HPhbpy (6-phenyl-2,2'-bipyridine) or from the versatile precursor [Ni(HPhbpy)Br2]2. Different from previously necessary C‒Br oxidative addition at Ni(0), an extended scan of reaction conditions allowed quantitative access to the title compound from Ni(II) on synthetically useful timescales through base-assisted C‒H activation in nonpolar media at elevated temperature. Optimisation of the reaction conditions (various bases, solvents, methods) identified 1:2 mixtures of acetate and carbonate as unrivalled synergetic base pairs in the optimum protocol that holds promise as a readily usable and easily tuneable access to a wide range of direct nickelation products. While for the base-assisted C‒H metalation of the noble metals Ru, Ir, Rh, or Pd, this acetate/carbonate method has been established for a few years, our study represents the leap into the world of the base metals of the 3d series.
Original language | English |
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Article number | 997 |
Number of pages | 13 |
Journal | Molecules |
Volume | 25 |
Issue number | 4 |
DOIs | |
Publication status | Published - 24 Feb 2020 |
Keywords
- 6-PHENYL-2,2-BIPYRIDINE
- ACTIVATION
- BONDS
- C-H activation
- CRYSTAL-STRUCTURE
- FUNCTIONALIZATION
- LIGAND
- NICKEL(II) COMPLEXES
- PALLADIUM(II)
- PLATINUM
- PT-II
- base-assisted
- cyclometalation
- cyclonickelation
- organonickel