Transmetallation anodic

The reaction is the electrochemical version of the well-known transmetallation with lead salts, and becomes significant when the lead anode oxidizes. The very high current yields (Ca 170-180%) imply that formation of R4Pb by nonelectrodic reactions takes place as well ... 

The mechanism of the Zn chloride-assisted, palladium-catalyzed reaction of allyl acetate (456) with carbonyl compounds (457) has been proposed [434]. The reaction involves electroreduction of a Pd(II) complex to a Pd(0) complex, oxidative addition of the allyl acetate to the Pd(0) complex, and Zn(II)/Pd(II) transmetallation leading to an allylzinc reagent, which would react with (457) to give homoallyl alcohols (458) and (459) (Scheme 157). Substituted -lactones are electrosynthesized by the Reformatsky reaction of ketones and ethyl a-bromobutyrate, using a sacrificial Zn anode in 35 92% yield [542]. The effect of cathode materials involving Zn, C, Pt, Ni, and so on, has been investigated for the electrochemical allylation of acetone [543]. 

RX, thus affording the corresponding RNiX compounds. In the presence of zinc(II) ions, this intermediate would undergo a transmetallation reaction to produce the organozinc compound RZnX. Note that zinc(II) ions can be brought either by addition of a zinc salt (ZnBr2 or ZnCl2) in the solution or by oxidation of a zinc anode. 

Organometallics can be generated in laboratory or industrial scale by anodic transmetalation RMEj------- RME2 (Eq. (275) ). 

Current synthetic methods for the preparation of Pd-based electrocatalysts for anodes of DAFCs are manifold, including reduction of high-valent metal compounds with chemical agents, colloidal metal deposition, electrodeposition and transmetalation... 

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