Design of a green chemoenzymatic cascade for scalable synthesis of bio-based styrene alternatives. Issue 18 (8th August 2022)

• Record Type: Journal Article
• Authors: Petermeier, Philipp; Bittner, Jan Philipp; Müller, Simon; Byström, Emil; Kara, Selin
• Is Part Of: Green chemistry. Volume 24:Issue 18(2022)
• Page Start: 6889
• Page End: 6899
• Publication Date: 2022-08-08
• Subjects: Environmental chemistry -- Industrial applications -- Periodicals; Environmental management -- Periodicals; 660
• DOI: 10.1039/d2gc01629j
• Languages: English
• ISSNs: 1463-9262

Abstract

Abstract : We present the strategic development of a synthetic onepot two-step process for the manufacture of acetyl-protected hydroxystyrenes from phenolic acid substrates using environmentally benign (bio)catalysts in an eco-friendly solvent. Abstract : 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.