Transfer Hydrogenation and Transfer Hydrogenolysis. XV.
Homogeneous Selective Hydrogenation of Various Fatty Acid Methyl Esters by Organic Hydrogen Donors
1978 年 27 巻 2 号 p. 70-75
詳細
1978 年 27 巻 2 号 p. 70-75
The reduction of methyl esters of C18-unsaturated acids by the hydrogen transfer from organic compounds was examined in the presence of homogeneous catalysts. The hydrogen transfer systems are devided into two groups. The one to which indoline- (NH4) 2PdCl4, indoline-PdCl2, and isopropyl alcohol-RuCl2 (PPh3) 3 belong showed following characteristics : (1) the reactivity of linoleate was much higher than that of trans-9. trans-12-octadecadienoate. (2) The reactivity of alkali conjugated dienes was much higher than that of linoleate. (3) The selectivity to monoenes was complete in the reaction of dienes and oleate and elaidate were not reduced. (4) The rate of cis-trans isomerization was much slower than that of the reduction of dienes. The other group to which indoline-RuCl2 (PPh3) 3, glucose-RuCl2 (PPh3) 3, and the reactions catalyzed by RuH2 (PPh3) 4 belong has following characteristics : (1) the reactivity of the nonconjugated trans, trans-diene was higher than that of linoleate, and was comparable with that of the conjugated dienes. (2) The rate of the isomerization was fast, cis-trans equilibrium of monoenes was reached, and the position of the equilibrium was varied by hydrogen donors. (3) In most cases the selectivity to monoenes was incomplete and the monoenes also reduced.
