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Stoichiometric and Catalytic Aryl−Cl Activation and Borylation using NHC‐stabilized Nickel(0) Complexes
Author(s) -
Kuehn Laura,
Jammal Dominik G.,
Lubitz Katharina,
Marder Todd B.,
Radius Udo
Publication year - 2019
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201900937
Subject(s) - borylation , aryl , catalysis , chemistry , carbene , nickel , medicinal chemistry , stoichiometry , boron , oxidative addition , polymer chemistry , organic chemistry , alkyl
NHC‐nickel (NHC= N ‐heterocyclic carbene) complexes are efficient catalysts for the C−Cl bond borylation of aryl chlorides using NaOAc as a base and B 2 pin 2 (pin=pinacolato) as the boron source. The catalysts [Ni 2 (ICy) 4 (μ‐(η 2 :η 2 )‐COD)] ( 1 , ICy=1,3‐dicyclohexylimidazolin‐2‐ylidene; COD=1,5‐cyclooctadiene), [Ni(ICy) 2 (η 2 ‐C 2 H 4 )] ( 2 ), and [Ni(ICy) 2 (η 2 ‐COE)] ( 3 , COE=cyclooctene) compare well with other nickel catalysts reported previously for aryl‐chloride borylation with the advantage that no further ligands had to be added to the reaction. Borylation also proceeded with B 2 neop 2 (neop=neopentylglycolato) as the boron source. Stoichiometric oxidative addition of different aryl chlorides to complex 1 was highly selective affording trans ‐[Ni(ICy) 2 (Cl)(Ar)] (Ar=4‐(F 3 C)C 6 H 4 , 11 ; 4‐(MeO)C 6 H 4 , 12 ; C 6 H 5 , 13 ; 3,5‐F 2 C 6 H 3 , 14 ).