Noels' vs. grubbs' catalysts: Evidence for one unique active species for two different systems!

Abstract

The catalytically active propagating species involved in the self-metathesis of ethyl oleate obtained from the multi-component Noels' catalytic system {[RuCl2(p-cymene)(PCy3)] + Me 3SiCHN2} are probably the same as those of the single-component well-defined Grubbs' 1st generation catalyst, [Cl 2Ru=CHPh(PCy3)2] (1-Ph). In the case of the Noels' catalyst, it involves the de-coordination of p-cymene, and the redistribution of PCy3 ligands to generate only 5-10% of [Cl 2Ru=CHR(PCy3)2], where R = CH-(CH 2)6-CH3 (1-Oct) and R = CH-(CH 2)6-COOEt (1-E), while 1-Ph can generate 100% of these species. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.