747369-48-8Relevant academic research and scientific papers
Redox Reactions of cis-Dialkylcobalt(III) Complexes with Benzyl and Allyl Bromides, Induced by Thermal Cleavage of the Cobalt-Carbon Bond
Ishikawa, Kunio,Fukuzumi, Shunichi,Tanaka, Toshio
, p. 563 - 570 (1987)
The thermal cleavage of the cobalt-carbon bond of cis-dialkylcobalt(III) complexes, cis-+ (R = Me, Et, and PhCH2; bpy = 2,2'-bipyridine), was enhanced by the presence of benzyl and allyl bromide, inducing the C-C bond formation to yield mainly 1,2-diphenylethane and 1,5-hexadiene, respectively.In the cis-+-allyl bromide system, a comparable amount of the cross-coupling product (4-phenyl-1-butene) was obtained together with the homo-coupling products (1,2-diphenylethane and 1,5-hexadiene).The enhancement of the thermal cleavage of the cobalt-carbon bond of cis-+ by the reactions with benzyl and allyl bromides is caused by the high reactivity of the carbanion ligand of + produced by the homolytic cleavage of the cobalt-carbon bond of cis-+, which undergoes the exchange, coupling, and cross-coupling reactions with benzyl and allyl groups of the bromides.Based on the kinetics and the activation parameters, the cobalt-carbon bond dissociation enthalpy of cis-+ has been estimated to be 92 kJ mol-1.
Photoredox reactions of cis-dialkylcobalt(III) complexes with benzyl and allyl bromides
Fukuzumi, Shunichi,Ishikawa, Kunio,Tanaka, Toshio
, p. 358 - 365 (2008/10/08)
When the photolysis of an acetonitrile solution of cis-dialkylcobalt(III) complexes cis-[R2CO(bpy)2]ClO4 (R = Me and Et; bpy = 2,2′-bipyridine) was carried out in the presence of benzyl or allyl bromide by using visible light, cis-[R2Co(bpy)2]ClO4 reacted with approximately three equivalent amounts of benzyl or allyl bromide to yield mainly the homocoupling products 1,2-diphenylethane or 1,5-hexadiene as well as a small amount of the cross-coupling product between the alkyl group of cis-[R2Co(bpy)2]ClO4 and the benzyl or allyl group of the bromide. On the other hand, in the photoredox reaction of cis-[(PhCH2)2Co(bpy)2] with benzyl or allyl bromide, cis-[(PhCH2)2Co(bpy)2] reacted with an equivalent amount of benzyl or allyl bromide to yield only the homocoupling product in the case of benzyl bromide or comparable amounts of the homocoupling and cross-coupling products in the case of allyl bromide. Reaction schemes of the photoredox reactions are discussed on the basis of ESR measurements to detect the reactive intermediates as well as the quantum yield measurements.
