Abstract
Direct conversion of 1-decene to petroleum range alkanes was obtained using hydro-metathesis reaction. To understand this reaction we employed three different well-defined single site catalysts precursors; [(Si-O-)W(CH3)(5)] 1, [(Si-O-)Mo((CBu)-Bu-t)((CH2Bu)-Bu-t)(2)] 2 and [(Si-O)Ta(=(CHBu)-Bu-t)((CH2Bu)-Bu-t)(2)] 3. We witnessed that in our conditions olefin metathesis/isomerization of 1-decene occurs much faster followed by reduction of the newly formed olefins rather than reduction of the 1-decene to decane, followed by metathesis of decane. We found that Mo-based catalyst favors [2+2] cycloaddition of 1-decene forming metallocarbene, followed by reduction of the newly formed olefins to alkanes. However, in the case of W and Ta-based catalysts, a rapid isomerization (migration) of the double bond followed by olefin metathesis and reduction of the newly formed olefins were observed. We witnessed that silica supported W catalyst precursor 1 and Mo catalyst precursor 2 are better catalysts for hydro-metathesis reaction with TONs of 818 and 808 than Ta-based catalyst 3 (TON of 334). This comparison of the catalysts provides us a better understanding that, if a catalyst is efficient in olefin metathesis reaction it would be a better catalyst for hydro-metathesis reaction.