Valorisation of plant oil derivatives via metathesis reactions: study of the cross-metathesis of methyl oleate with cinnamaldehyde

Abstract

The cross-metathesis of methyl oleate (MO) with cinnamaldehyde (CA) to yield 2-undecenal, methyl 11-oxo-9-undecenoate, methyl 10-phenyl-9-decenoate and 1-decenylbenzene was investigated using the second-generation Hoveyda-Grubbs Ru complex (HG2). Self-metathesis of methyl oleate was the main undesired secondary reaction. The reaction was carried out at 323 K using reactant molar ratios (RCA/MO) between 1 and 20. The yield (YC-M) and selectivity (SC-M) to cross-metathesis products increased with RCA/MO until reaching both parameters 100% for RCA/MO = 20. The effect of temperature on catalyst activity and selectivity was investigated in the 303–363 K range; YC-M increased significantly with temperature at the expense of the formation of MO self-metathesis products. No significant HG2 deactivation was observed after performing three consecutive catalytic tests of MO/CA cross-metathesis at 323 K.