Catalytic synthesis of octadiene-1,7 from ethylene and cyclohexene

A new method is proposed for the synthesis of octadiene-1,7 by co-metathesis of ethylene and cyclohexene (ethenolysis). The reaction is carried out in a flow setup at elevated pressures using an original NH4ReO4/Al2O3 heterogeneous catalyst. At the first stage of the reaction, carbenes are formed as intermediates. The optimal conditions of the co-metathesis process were found. The catalyst developed provides the cyclohexene conversion about 25 wt. %, i.e. close to the thermodynamic limit, at the selectivity to octadiene-1,7 close to 100% (99.9%). The catalyst shows good stability in six cycles including 5-h catalytic runs with intermediate regenerative treatments. (C) 2018 Elsevier B.V. All rights reserved.