Main Article Content

Catalytic Hydrogenation of Sorbic Acid using Pyrazolyl Palladium(II) and Nickel(II) Complexes as Precatalysts


Oluwasegun E. Olaoye
Olayinka Oyetunji
Banothile C.E. Makhubela
Apollinaire Muyaneza
Gopendra Kumar
James Darkwa

Abstract

We have prepared several pyrazolyl palladium and nickel complexes ([(L1)PdCl2] (1), [(L2) PdCl2] (2), [(L3) PdCl2] (3), [(L1) NiBr2] (4), [(L2) NiBr2] (5) and [(L3)  NiBr2] (6)) by reacting 3,5-dimethyl-1H-pyrazole (L1), 3,5-di-tert-butyl-1H-pyrazole (L2) and 5-ferrocenyl-1H-pyrazole(L3) with [PdCl2(NCMe)2] or  [NiBr2(DME)] to afford mononuclear palladium and nickel complexes, respectively. These complexes were then investigated as pre-catalysts in the  hydrogenation of 2,4-hexadienoic acid (sorbic acid). The active catalysts from these complexes demonstrate significant activities under mild experimental  conditions. Additionally, the active catalysts show that the hydrogenation of sorbic acid proceeds in a sequential manner, where the less hindered C=C  bond (4-hexenoic acid) is preferentially reduced over the more hindered C=C bond (2-hexenoic acid).


Journal Identifiers


eISSN: 1996-840X
print ISSN: 0379-4350