Intramolecular hydrogen exchange in 2,3-dimethylbutane catalysed by nickel

✍ Scribed by Carlito B. Lebrilla; Wilhelm F. Maier

• Book ID: 104220138
• Publisher: Elsevier Science
• Year: 1983
• Tongue: French
• Weight: 129 KB
• Volume: 24
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)86380-7

✦ Synopsis

A cross experiment with a specifically labeled hydrocarbon reveals that intramolecular hydrogen exchange is an important process for saturated hydrocarbons chemisorbed on a nickel catalyst. Attack of unactivated C-H bonds represents the initial step of most important technical processes such as petroleum refining and functionalization of saturated hydrocarbons. Despite this importance little is known about the exact mechanism of C-H bond activation by heterogeneous catalysts. H/D exchange experiments have already been applied successfully to the investigation of some mechanistic aspects. 1 In this paper we present the first evidence for intramolecular hydrogen exchange in saturated hydrocarbons catalysed by nickel on silica.

All experiments have been conducted with a gas phase flow apparatus as described previously. 2

The substrate was vaporized in a stream of deuterium at atmospheric pressure and passed through the horizontal catalyst bed containing the nickel on silica catalyst.

3 The products were collected in a cold trap and separated by preparative GC. The experimental results are summarized in the table.The catalyst has been cleaned with deuterium at 4OO'C prior to each experiment.