Carbonylation of Glycerol and Other Polyols: A High Throughput Study of Feasibility

Abstract

The use of rhodium iodide catalysts in the carbonylation reaction of glycerine leads to saturated and unsaturated acids with C 4 -carbon backbone which can be integrated or are products of the petrochemical value chain. The ratio of the different saturated and unsaturated products can be controlled via the reaction conditions and the catalyst to promoter ratio. A study on potential reaction pathways was included in the study; all experiments were carried out in high throughput mode.

Carbodeoxygenation of Biomass: The Carbonylation of Glycerol and Higher Polyols to Monocarboxylic Acids

“…Both the mono-and di-acetylated species ((20) and (21)) formed very quickly at room temperature. Substitution of the acetate groups with iodide then occurs to produce species (22) as the major product after 25 hours at room temperature. 1-Hydroxy-2-iodoethane (23) can also be identified but in smaller amounts, this could be formed by the direct substitution of ethylene glycol (19), however this is unlikely as the ethylene glycol appears to become acetylated relatively easily.…”

“…1-Hydroxy-2-iodoethane (23) can also be identified but in smaller amounts, this could be formed by the direct substitution of ethylene glycol (19), however this is unlikely as the ethylene glycol appears to become acetylated relatively easily. Therefore, it is more likely to be species (22) that is hydrolysed as it is this species that builds up at room temperature. …”

“…The only other report in the literature on the carbonylation of glycerol is a recent high throughput study by Schunk and co-workers, who used [RhCl(CO) 2 ] 2 and MeI as the catalyst system and observed the formation of unsaturated acids such as vinyl acetic acid (VA) and crotonic acid (CA), in addition to the saturated acids BA and IBA. 22 The saturated and unsaturated C 4 acids are not the products one would immediately predict from the carbonylation of glycerol and no explanation has been provided so far for this surprising transformation. We present here the results of our extensive study on the carbonylation of glycerol, including mechanistic studies and a comparison between the performance of rhodium versus iridium-based catalysts.…”

Polymer supported rhodium carbonyl complex catalyzed carbonylation of glycerol for the synthesis of carboxylic acids

“…A rhodium complex [{RhCl(CO) 2 } 2 ] was used in combination with HI as the co-catalyst at 180 • C and 35 bar CO pressure and glycerol was converted after 80 min to a mixture of 45 mol% butyric (BA) and 30 mol% isobutyric acid (IBA). The only other report in the literature on the carbonylation of glycerol is a recent high-throughput study by Schunk and co-workers, who used [{RhCl(CO) 2 } 2 ] and CH 3 I as the catalyst system and observed the formation of unsaturated acids such as vinyl acetic acid (VA) and crotonic acid (CA), in addition to the saturated acids BA and IBA [25].…”

“…Reported homogeneous rhodium catalyzed glycerol carbonylation suffer from several disadvantages [25,26]. Homogeneous rhodium catalysts may easily be destroyed during the course of the reaction and they cannot be easily recovered after the reaction for reuse [27,28].…”