Alkane metathesis

In alkane metathesis acyclic alkanes are scrambled to higher and lower homologues with tantalum hydride supported on silica (SiO₂)TaH at temperatures of 25°C to 200°C. In this reaction ethane is converted into methane, propane and traces of butane. Cross metathesis can also take place. In this reaction methane and propane molecules react to 2 molecules of ethane and ethane reacts with toluene to ethylbenzene and xylene. The reaction involves metallacyclobutane intermediates just as in olefin metathesis.

References

• Metathesis of Alkanes Catalyzed by Silica-Supported Transition Metal Hydrides Véronique Vidal, Albert Théolier, Jean Thivolle-Cazat, Jean-Marie Basset, Science, Vol 276, Issue 5309, 99-102 4 April 1997 Abstract
• Primary Products and Mechanistic Considerations in Alkane Metathesis Jean Marie Basset, Christophe Copéret, Laurent Lefort, Barry M. Maunders, Olivier Maury, Erwan Le Roux, Guillaume Saggio, Sophie Soignier, Daravong Soulivong, Glenn J. Sunley, Mostafa Taoufik, and Jean Thivolle-Cazat J. Am. Chem. Soc.., 127 (24), 8604 -8605, 2005. Abstract