Direct Base-Assisted CâH Cyclonickelation of 6-Phenyl-2,2'-bipyridine.
Molecules
; 25(4)2020 Feb 24.
Article
en En
| MEDLINE
| ID: mdl-32102281
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 CâBr 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 CâH activation in nonpolar media at elevated temperature. Optimisation of the reaction conditions (various bases, solvents, methods) identified 12 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 CâH 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.
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MEDLINE
Asunto principal:
Piridinas
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Complejos de Coordinación
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Técnicas de Química Sintética
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Níquel
Límite:
Humans
Idioma:
En
Año:
2020
Tipo del documento:
Article