The electrochemical reduction of allyl halides is strongly catalysed when it is carried out by cathodically generating and continuously recycling the nickel(0) complex promoter |Ni(PPh3)4|(PPh3= triphenylphosphine). This species undergoes oxidative addition by allyl halides leading to π-bonded organometallic nickel(I) derivatives, the metal-carbon bond of which is cleaved by means of an electrochemical reduction providing 1,5-hexadiene as the coupling product and renewing the nickel(0) promoter, thus allowing an electrocatalytic cycle to be completed. Voltammetric, coulometric and gas-chromatographic data are presented and analysed. To account for the catalytic action of the nickel(0) complex, a mechanistic scheme is proposed which is consistent with the kinetic data obtained by studying the chemical reaction coupled with charge transfers by means of the voltammetric technique. © 1984 Elsevier Sequoia S.A.
An electroanalytical investigation on the electrocatalysed coupling of allyl halides promoted by the nickel-triphenylphosphine system
DANIELE, Salvatore;
1984-01-01
Abstract
The electrochemical reduction of allyl halides is strongly catalysed when it is carried out by cathodically generating and continuously recycling the nickel(0) complex promoter |Ni(PPh3)4|(PPh3= triphenylphosphine). This species undergoes oxidative addition by allyl halides leading to π-bonded organometallic nickel(I) derivatives, the metal-carbon bond of which is cleaved by means of an electrochemical reduction providing 1,5-hexadiene as the coupling product and renewing the nickel(0) promoter, thus allowing an electrocatalytic cycle to be completed. Voltammetric, coulometric and gas-chromatographic data are presented and analysed. To account for the catalytic action of the nickel(0) complex, a mechanistic scheme is proposed which is consistent with the kinetic data obtained by studying the chemical reaction coupled with charge transfers by means of the voltammetric technique. © 1984 Elsevier Sequoia S.A.I documenti in ARCA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.