Catalytic Conversion of Renewable Resources into Bulk and Fine Chemicals

Abstract

Several strategies can be chosen to convert renewable resources into chemicals. In this account, I exemplify the route that starts with so-called platform chemicals; these are relatively simple chemicals that can be produced in high yield, directly from renewable resources, either via fermentation or via chemical routes. They can be converted into the existing bulk chemicals in a very efficient manner using multistep catalytic conversions. Two examples are given of the conversion of sugars into nylon intermediates. 5-Hydroxymethylfurfural (HMF) can be prepared in good yield from fructose. Two hydrogenation steps convert HMF into 1,6-hexanediol. Oppenauer oxidation converts this product into caprolactone, which in the past, has been converted into caprolactam in a large-scale industrial process by reaction with ammonia. An even more interesting platform chemical is levulinic acid (LA), which can be obtained directly from lignocellulose in good yield by treatment with dilute sulfuric acid at 200°C. Hydrogenation converts LA into gamma-valerolactone, which is ring-opened and esterified in a gas-phase process to a mixture of isomeric methyl pentenoates in excellent selectivity. In a remarkable selective palladium-catalysed isomerising methoxycarbonylation, this mixture is converted in to dimethyl adipate, which is finally hydrolysed to adipic acid. Overall selectivities of both processes are extremely high. The conversion of lignin into chemicals is a much more complicated task in view of the complex nature of lignin. It was discovered that breakage of the most prevalent β-O-4 bond in lignin occurs not only via the well-documented C3 pathway, but also via a C2 pathway, leading to the formation of highly reactive phenylacetaldehydes. These compounds went largely unnoticed as they immediately recondense on lignin. We have now found that it is possible to prevent this by converting these aldehydes in a tandem reaction, as they are formed. For this purpose, we have used three different methods: acetalisation, hydrogenation, and decarbonylation. These reactions were first established in the tandem reactions of model compounds, but subsequently, we were able to show that this works equally well on organosolv lignin and even on lignocellulose.

Comprehensive investigation of succinic acid production by Actinobacillus succinogenes: a promising native succinic acid producer

“…Over the past two decades, the metabolic engineering of microorganisms has attracted increasing attention for bulk and fine chemical production from renewable resources. 58,59 Formate and acetate were main byproducts during A. succinogenes anaerobic fermentation, restricting succinic acid yield and affecting the process economics. Bioprocess optimization was an effective strategy for metabolic flux redistribution.…”

Cyclopentanone Derivatives from 5‐Hydroxymethylfurfural via 1‐Hydroxyhexane‐2,5‐dione as Intermediate

“…We are interested in the catalytic conversion of platform chemicals derived from renewable resources into known or new chemicals. [1] 5-Hydroxymethylfurfural (HMF;S cheme 1, 1)i so btained from the dehydration of fructose and has become aw ell-known platform chemicalf or the productiono fn umerous valuable chemicals, such as 2,5-furandicarboxylica cid. [2] Recently,w eh ave become interested in the further development of 1-hydroxyhexane-2,5dione (HHD, 2), ap roduct of the hydrogenation/hydrolytic ring openingo fH MF (Scheme 1).Several catalytic systemsh ave been reported to produce HHD.…”

Nylon Intermediates from Bio‐Based Levulinic Acid

“…[23] These were subjected to ap alladium-catalysed isomerising methoxycarbonylation in the presence of methanol and CO at ap ressure of 20 bar (Scheme 5). [24] Forthis transformation, acatalyst made in situ from Pd(OAc) 2 and 1,2-bis(di-t-butylphosphinomethyl)benzene (dppx) was used to isomerise the internal alkenes to the terminal position and form the desired dimethyl adipate. [25] Full conversion of the pentenoates and the subsequent isolation of the adipate product in 91 %yield was successfully achieved.…”