Does the rate of competing isomerisation during alkene metathesis depend on pre-catalyst initiation rate?

Nelson, D.J. and Percy, J.M. (2014) Does the rate of competing isomerisation during alkene metathesis depend on pre-catalyst initiation rate? Dalton Transactions, 43 (12). pp. 4674-4679. ISSN 1477-9234 (https://doi.org/10.1039/c4dt00007b)

Full text not available in this repository.Request a copy

Abstract

Experimental studies of the ring-closing metathesis reaction of 1,8-nonadiene and the ROMP reaction of cycloheptene show that the rate of isomerisation is not correlated to the initiation rate of the pre-catalyst, and that the absence of phosphine leads to a greatly increased rate of isomerisation. A range of pre-catalysts and solvents were probed and it is proposed that the isomerisation is mediated by a ruthenium hydride complex; our results are consistent with the rate-determining formation of such a species, which might be trapped in situ by tricyclohexylphosphane.