72122-06-6Relevant academic research and scientific papers
Directing aryl-I versus aryl-Br bond activation by nickel via a ring walking process
Zenkina, Olena V.,Karton, Amir,Freeman, Dalia,Shimon, Linda J. W.,Martin, Jan M. L.,Van Der Boom, Milko E.
, p. 5114 - 5121 (2009/02/04)
Activation of a strong aryl-Br bond of a halogenated vinylarene by nickel(0) is demonstrated in the presence of aryl-I containing substrates. η2-Coordination of Ni(PEt3)2 to the C=C moiety of halogenated vinylarenes is kinetically preferable and is followed by an intramolecular aryl-halide bond activation process. This ring- walking process is quantitative and proceeds under mild reaction conditions in solution. Mechanistic studies indicate that the metal insertion into the aryl-halide bond is not the rate-determining step. The reaction obeys first-order kinetics in the η2-coordination complexes with almost identical activation parameters for Br and I derivatives. The ring-walking process is kinetically accessible as shown by density functional theory (DFT) calculations at the PBE0/SDB-cc-pVDZ//PBE0/SDD level of theory.
