Abstract
The importance of synthesis of carbon-carbon bonds is reflected by the fact that Nobel Prizes in Chemistry have been given to this area: The Grignard reaction (1912), the Diels-Alder reaction (1950), the Witting reaction (1979), the olefin metathesis Y. Chauvin, R.H. Grubbs and R.R. Schrock (2005), the palladium- catalyzed cross-coupling reactions to R. F. Heck, A. Suzuki, E. Negishi.
Here, we present the new heterogeneous catalytic cross-coupling reaction of a number of bio-oxygenates that lead to expand considerably the hydrocarbons incorporating. For catalytic experiments, mono- and bimetallic Pt-M and Re-M were used. As substrates we used ethanol (the most shared bioalcohol), glycerol (co-product of biodiesel production), n-butanol, propanol and acetone (prospective bioproducts) and vegetable oil.
It was found that the main products of ethanol conversion are alkanes with even number of carbon atoms. When we used C3 co-reagents (propanol, acetone, glycerol) products composition was enriched with hydrocarbons with odd number of carbon atoms. That gave us a reason to propose cross-coupling reactions take place during combined conversion of bio-oxygenates. Glycerol was found to be the best co-reagent to ethanol. Its addition (not more than 40 wt.%) to ethanol halves C1-C2 yields and increases hydrocarbons yield by 20-30 wt.% in comparison with pure ethanol conversion products.
