The EPR study of the promotion effect of alcohols on the (PPh3)(4)Ni+BF3 center dot OEt2 catalytic system

To develop notions on the mechanism of the promoting effect of alcohols on the (PPh3)(4)Ni + nBF(3). OEt2 catalytic system, the reactions between the individual Ni(I) alkoxyl complexes and boron trifluoride etherate were stud ied by the EPR method, as were the processes running in the catalytic syste m in situ during its promotion. It was shown that during the interaction of the Ni(I) alkoxyl complexes with the boron trifluoride etherate, the alkox yl acidoligands are exchanged for the fluoride anion and the phosphine liga nds are slightly eliminated from the coordination sphere of Ni(I). Alcohols introduced into the catalytic system undergo dehydration. The promoting ef fect of the alcohol in the catalytic system reduces to the facilitation of the phosphine ligand elimination, which is due to the formation of the NI(I ) alkoxy complexes and the generation of the Ni-R(H) active particles as a result of the insertion of the unsaturated hydrocarbon molecules along the Ni-OR bond.