Selective laccase-catalyzed dimerization of phenolic compounds derived from lignin: Towards original symmetrical bio-based (bis) aromatic monomers

Audrey Llevot (1) , Etienne Grau (1, 2) , Stéphane Carlotti (1, 3) , Stéphane Grelier (1, 2) , Henri Cramail (1, 2)

1 LCPO - Laboratoire de Chimie des Polymères Organiques
2 Team 2 LCPO : Biopolymers & Bio-sourced Polymers
3 Team 1 LCPO : Polymerization Catalyses & Engineering

A laccase-catalyzed process was developed to prepare, selectively, in high yield, dimers of lignin based phenolic compounds without any purification. The influence of experimental parameters such as laccase loading, nature of solvent and the presence of oxygen on the conversion of vanillin was investigated. After the dimerization, the product obtained as a precipitate is filtered off and the solution containing the enzyme can be re-used several times, which improves the process economics. A phenolic-substrate screening reveals that such process enables to dimerize regioselectively, six orthomethoxy-para-substituted phenols (vanillin, 4-hydroxy-3-methoxybenzonitrile, acetovanillon, methyl vanillate, 2-methoxy-4-methylphenol, and eugenol) with yields ranging from 87% to 96% and one orthodisubstituted phenol (2,6-dimethoxyphenol) with 80% yield.

Mots clés: LIGNOCELLULOSIC BIOMASS; MEDIATED OXIDATION; OXIDATIVE POLYMERIZATION; Enzymatic catalysis; Dimerization; Lignin; Laccase; DERIVATIVES; GREEN; VANILLIN; DEPOLYMERIZATION; 6-DIMETHOXYPHENOL; 2; FERULIC ACID; CHEMICALS

Domaines: Polymères; Catalyse; Chimie

Audrey Llevot, Etienne Grau, Stéphane Carlotti, Stéphane Grelier, Henri Cramail. Selective laccase-catalyzed dimerization of phenolic compounds derived from lignin: Towards original symmetrical bio-based (bis) aromatic monomers. Journal of Molecular Catalysis B: Enzymatic, 2016, 125, pp.34-41. ⟨10.1016/j.molcatb.2015.12.006⟩. ⟨hal-01364939⟩