TY - JOUR

T1 - Design of a green chemoenzymatic cascade for scalable synthesis of bio-based styrene alternatives

AU - Petermeier, Philipp

AU - Bittner, Jan Philipp

AU - Müller, Simon

AU - Byström, Emil

AU - Kara, Selin

N1 - Funding Information: This project has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no. 860414 and from the Deutsche Forschungsgemeinschaft (DFG) under grant number KA 4399/3-1 and JA 2500/5-1. The authors thank Prof. Robert Kourist from TU Graz (AT) for the kind provision of the BsPAD gene and Michelle Leganger Juul Sørensen from Aarhus University (DK) for her kind technical support in enzyme production.

PY - 2022/8/8

Y1 - 2022/8/8

N2 - As renewable lignin building blocks, hydroxystyrenes are particularly appealing as either a replacement or addition to styrene-based polymer chemistry. These monomers are obtained by decarboxylation of phenolic acids and often subjected to chemical modifications of their phenolic hydroxy groups to improve polymerization behaviour. Despite efforts, a simple, scalable, and purely (chemo)catalytic synthesis of acetylated hydroxystyrenes remains elusive. We thus propose a custom-made chemoenzymatic route that utilizes a phenolic acid decarboxylase (PAD). Our process development strategy encompasses a computational solvent assessment informing about solubilities and viable reactor operation modes, experimental solvent screening, cascade engineering, heterogenization of biocatalyst, tailoring of acetylation conditions, and reaction upscale in a rotating bed reactor. By this means, we established a clean one-pot two-step process that uses the renewable solvent CPME, bio-based phenolic acid educts and reusable immobilised PAD. The overall chemoenzymatic reaction cascade was demonstrated on a 1 L scale to yield 18.3 g 4-acetoxy-3-methoxystyrene in 96% isolated yield.

AB - As renewable lignin building blocks, hydroxystyrenes are particularly appealing as either a replacement or addition to styrene-based polymer chemistry. These monomers are obtained by decarboxylation of phenolic acids and often subjected to chemical modifications of their phenolic hydroxy groups to improve polymerization behaviour. Despite efforts, a simple, scalable, and purely (chemo)catalytic synthesis of acetylated hydroxystyrenes remains elusive. We thus propose a custom-made chemoenzymatic route that utilizes a phenolic acid decarboxylase (PAD). Our process development strategy encompasses a computational solvent assessment informing about solubilities and viable reactor operation modes, experimental solvent screening, cascade engineering, heterogenization of biocatalyst, tailoring of acetylation conditions, and reaction upscale in a rotating bed reactor. By this means, we established a clean one-pot two-step process that uses the renewable solvent CPME, bio-based phenolic acid educts and reusable immobilised PAD. The overall chemoenzymatic reaction cascade was demonstrated on a 1 L scale to yield 18.3 g 4-acetoxy-3-methoxystyrene in 96% isolated yield.

UR - http://www.scopus.com/inward/record.url?scp=85135712834&partnerID=8YFLogxK

U2 - 10.1039/d2gc01629j

DO - 10.1039/d2gc01629j

M3 - Article

VL - 24

SP - 6889

EP - 6899

JO - Green chemistry

JF - Green chemistry

SN - 1463-9262

IS - 18

ER -