Cobalt catalysed processes for higher alkenes

In Chapter 8 we will discuss the hydroformylation of propene using rhodium catalysts. Rhodium is most suited for the hydroformylation of terminal alkenes, as we shall discuss later. In older plants cobalt is still used for the hydroformylation of propene, but the most economic route for propene hydroformylation is the Ruhrchemie/Rhone-Poulenc process using two-phase catalysis with rhodium catalysts. For higher alkenes, cobalt is still the preferred catalyst, although recently major improvements on rhodium (see Chapter 8) and palladium catalysts have been reported [3], 

The higher alkene feed (C10-14) for the production of detergent alcohols is either a product from the wax-cracker (terminal and internal alkenes) or the byproduct of the ethene oligomerisation process (internal alkenes). In the near future a feed from high-temperature Fischer-Tropsch may be added to this. The desired aldehyde (or alcohol) product is the linear one and the cobalt catalyst must therefore perform several functions  

In general the activity of transition metal complexes for alkene isomerisation is low in the presence of carbon monoxide, but HCo(CO)4 is an exception to this rule. Depending on conditions, full equilibration of the alkene isomers is obtained. 

In the first few minutes of a batch reaction using 1-alkenes an extremely fast reaction therefore may take place, which is the direct hydroformylation of 1-alkene, but after an equilibration to the internal isomers has taken place the reaction slows down considerably. 

Perhaps by using partly deuterated feeds one can design an experiment to find prooffor the chain running mechanism in the reaction below. 

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