Electrochemical synthesis of the σ-aryl complex [NiBr(Mes)(bpy)] and its use as catalyst precursor for the oligomerization of ethylene (Mes=2,4,6-trimethylphenyl, bpy=2,2′-bipyridine)

Electron transfer in organonickel complexes of α-diimines: Versatile redox catalysts for C–C or C–P coupling reactions – A review

“…2) [28,31,32]. In the presence of aryl bromides, the anodic component of the first wave (C 1 ) disappears, and two new waves (C 3 and C 4 ) emerge at more negative potentials.…”

“…nickel r-aryl complexes [Ni(Ar)Br(bpy)]. A number of such complexes have been prepared independently either by electrochemical means [28,32,33] or by chemical methods (see Scheme 4, reaction A) [34][35][36][37]. In this latter case also other a-diimine ligands were introduced and the complexes were submitted to detailed studies of their electrochemical properties using electrochemical and spectroelectrochemical (UV-vis-NIR and EPR) methods [38].…”

“…For the sake of completeness the preparative routes to aryl nickel complexes [Ni(Ar)X(bpy)] from [Ni(Et) 2 (bpy)] and aryl halides ArX (Ar = Ph, 2-Tol, 3-Tol, 4-Tol and 2-ClPh, X = I, Br or Cl) [39], or using the oxidative addition reaction of aryl halides to [Ni(COD) 2 ] (COD = 1,5-cyclooctadiene) have to be quoted [30,32,40].…”

“…Recently the complex was shown to be an excellent catalyst precursor for the oligomerisation of ethylene [32]. It can be prepared by the reduction of [NiBr 2 (bpy)] in the presence of MesBr (1:1) at a potential E C 1 p of À1.55 V (vs. SCE), passing of 2F ( Fig.…”

The use of sacrificial anodes for the electrochemical synthesis of metallic complexes

“…The same procedure was also used for the synthesis of [NiBr(Mes)(bipy)] [311] and The electrosyntheses of diorganotin halides were also described [315]; the electrolysis of benzene solutions of alkyl or aryl halides with tin anodes gave the corresponding R 2 SnI 2 compounds (R = Me, Et); moreover, the adducts [R 2 Sn 2 X]·L', where L' = DMSO, CH 3 CN, bipy, phen, dppe, were also obtained (R = Me, Et, Bu n , Ph; X = Cl, Br, I; not all the combinations) by using this one step procedure applied to solutions which also contained the corresponding co-ligand. For the reaction with bipy, the addition of MeOH to the initial solution was necessary due to the low solubility of bipy in benzene.…”