Derivados do linoleato de etila a partir da metátese olefinas em função do catalisador e das condições reacionais

Abstract

Olefin metathesis of ethyl linoleate (EL), with 65% purity, was investigated under different conditions of substrate amount, temperature, and catalyst. Catalytic products were analyzed for GC-MS and discussed in terms of relative percent of the metathesis products. With G2 as catalyst, GC-MS chromatograms were similar in all the amounts of EL investigated at 50 °C for 24 h, except for ethyl hexadec-9- enoate (compound K), which was obtained with different percentage as a function of EL. The α, ω-dicarboxylic acid with m / z = 444.00 (compound L), produced by the LE metathesis reactions did not change in its formation percentage at 50 ° C in 24 h, however at 20 ° C in that same Time the relative percentage of L changed with increasing LE volume. Experiments were performed with LE (99%) and Ethyl Oleate (99%) with G2, the chromatograms showed products similar to the experiments performed with LE (65%) except for the presence of dodec-6-ene (compound H) in the LE chromatogram (99%).The olefin metathesis of EL (65%) conducted by G1 reached lower selectivity than that conducted by G2 for 24 h at 50 °C. However G1 showed to be very active for LE (65%) metathesis reactions. Several intense peaks reached with G1 were similar to those obtained with G2, in addition to new peaks of medium intensity. Compound L showed higher m/z, similar to that presented with G2, but with lower relative proportion in the mixture. [RuCl2(PPh3)2peridroazepina] PEP was inert for olefin metathesis of EL; however, it was activated in the presence of SnCl2 at 50 °C for 24h. Different compounds and selectivity as a function of the catalyst type and reaction conditions were obtained.