Development of Palladium–Carbene Catalysts for Telomerization and Dimerization of 1,3‐Dienes: From Basic Research to Industrial Applications

Abstract

The following account summarises recent developments in the area of palladium-catalysed telomerisation and dimerisation reactions of 1,3-dienes. The most active types of catalyst, palladium-carbene complexes, were tested in pilot plant and proved to be industrially viable.

Palladium‐Catalysed Telomerisation of Isoprene with Glycerol and Polyethylene Glycol: A Facile Route to New Terpene Derivatives

“…[14,15] To tackle the less reactive isoprene, we turned to Pd-carbene complexes, that were shown to be highly active and selective in several recent studies, [16][17][18][19] most notably by Beller and co-workers. [20][21][22] Since isoprene and glycerol are immiscible at practical concentrations, we achieved a monophasic reaction medium by adding various co-solvents. Surprisingly, we found that mixing glycerol and polyethylene glycol (PEG) gave a highly reactive system, where both the glycerol and the PEG were telomerised in good yields and selectivities.…”

Pd-Catalyzed Telomerization of 1,3-Dienes with Multifunctional Renewable Substrates: Versatile Routes for the Valorization of Biomass-Derived Platform Molecules

“…As discussed in the introduction, the telomerization with methanol is the first step in the production of 1-octene by Dow Chemical in their Tarragona plant, presumably using palladium with an aryl phosphine ligand. Beller and coworkers have also reported significant advancements in the telomerization of methanol, using N-heterocyclic carbene ligands instead [8]. A few examples that use ethanol have also been reported, evidently readily available from renewable resources, as the telogen [30,66,67].…”

“…The carbene complex was also shown to be active for a large number of other nucleophiles, including isopropanol, 1-butanol, benzyl alcohol, phenol and ethylene glycol [40]. An overview of the historic development of the use of N-heterocyclic carbenes in telomerization reactions up to the point of industrial application on a multi-ton scale by Evonik Oxeno is available [8].…”

“…The product is then fully hydrogenated and subsequently cracked to 1-octene and methanol for recycle (Scheme 2). A similar process has also been patented by Oxeno Olefinchemie and was run on a pilot plant scale by Evonik Oxeno in Marl, Germany [7,8]. Shell patented a telomerization process for 1-octene production that involves telomerization of butadiene with a carboxylic acid, e.g.…”

“…The novel catalyst system based on palladium(0) N-heterocyclic carbene complexes was developed by the group of Beller, in part prompted by the strong patent position of Dow on phosphine-based palladium catalysts [8]. The catalyst [37], either generated in situ from the corresponding imidazolium salt or the molecularly defined divinyldisiloxane complex [Pd(Imes)(dvds)] (Fig.…”