Ruthenium catalyzed 2-octene

On the other hand, the ruthenium-catalyzed addition of alkenes to alkynes involves a jr-allylruthenium intermediate [40]. Heating a 1 1 mixture of 1-octene and 1-octyne in 3 1 DMF-water at 100 °C with 5 mol% of ruthenium complex (C5H5)RuCl(cod) for 2 h gave a 1 1 adduct, the spectroscopic properties of which clearly showed it to be a branched 1,4-diene with a small amount of the regioiso-meric linear adduct (Eq. 5.26). 

Scheme 5.32 Ruthenium-catalyzed isomerization-hydroaminomethylation of 2-octene with piperidine.

The possibility of phosphine or NHC ligand dissociation from the respective flrst-and second-generation hemilabile carbenes should not be excluded, because it is generally assumed that ruthenium-catalyzed metathesis reactions proceed through 14-electron intermediates. Conseqnently, we have postulated a mechanism for the first- and second-generation hemilabile-catalyzed 1-octene metathesis reaction (Scheme 12.3) whereby the 0,N-ligand remains attached to the Ru-center. 

The same acidic chloroaluminate ionic liquids have been used as solvent for tungsten aryl oxide complexes for the metathesis of alkenes [24]. Slightly acidic chloroaluminates also dissolve the [Cl2W=NPh(PMe3)3] complex which catalyze ethene oligomerization without the addition of co-catalysts [25]. In a similar way, Ni-catalyzed 1-butene dimerization into linear octenes was carried out in acidic chloroaluminates buffered with small amount of weak bases [26]. Neutral chloroaluminates (l-ethyl-3-methylimidazolium chloride/AlCl3 = 1) were employed to immobilize ruthenium carbene complexes for biphasic ADMET (acyclic diene metathesis) polymerization of an acyclic diene ester [27]. 

Gross et al. reported the first use of a chiral ruthenium porphyrin Ru"(L,)(CO) as a catalyst for styrene epoxidation . Chiral ruthenium porphyrin systems have also been reported by Che et a/. . The utilization of another chiral ruthenium porphyrin, Ru"(L2)(CO) as a catalyst for enantioselective epoxidation of olefins with 2,6-dichloropyridine A-oxide has been described by Berkessel and Frauenkron ". The highest enantiomeric excesses of the oxiranes were obtained in the epoxidation of tetrahydronaphthalene and styrene, 77% and 70% ee, respectively, with high jdelds (up to 88%). Terminal aliphatic olefins and tra 5-disubstituted olefins, represented by 1-octene and rraw-stilbene, were sluggish substrates and gave low ee s. The epoxidation of tetrahydronaphthalene with iodosylbenzene catalyzed by Ru(II)(L2)(CO) produced only 52% ee... 

With methyl oleate, 53% yield of the terminal alcohol was observed. With unmodified internal olefins (2-decene, 2-tridecene, 4-octene), even higher regioselectivities in favor of the terminal alcohol could be achieved l/b up to 12 1). Proof was given that both rhodium and ruthenium complexes catalyze the isomerization-hydroformylation-hydrogenation reaction in a cooperative manner. 

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