Brønsted Acid Catalyzed Tandem Defunctionalization of Biorenewable Ferulic acid and Derivates into Bio‐Catechol

Abstract

An efficient conversion of biorenewable ferulic acid into bio-catechol has been developed. The transformation comprises two consecutive defunctionalizations of the substrate,t hat is,C ÀO( demethylation) and CÀC( de-2-carboxyvinylation) bond cleavage,occurring in one step.The process only requires heating of ferulic acid with HCl (or H 2 SO 4 )a s catalyst in pressurized hot water (250 8 8C, 50 bar N 2 ). The versatility is shown on av ariety of other (biorenewable) substrates yielding up to 84 %di-(catechol, resorcinol, hydroquinone) and trihydroxybenzenes (pyrogallol, hydroxyquinol), in most cases just requiring simple extraction as work-up.

Muconic acid isomers as platform chemicals and monomers in the biobased economy

“…46 In the last years, the development in the biomass conversion schemes opens routes to obtain catechol, phenol and other aromatic compounds directly from biomass feedstocks, creating new petroleum-free methods for producing MA. [47][48][49][50][51] The highest titers were reported from the fed-batch transformation of catechol using biological strains (Table 2). Fed-batch processes were used to control the substrates concentration below the inhibitory levels, and thus increase the productivity by avoiding substrate toxicity on the bacteria during production.…”

Selective demethylation reactions of biomass-derived aromatic ether polymers for bio-based lignin chemicals

“…3.9) a proton-catalyzed mechanism dominates while at higher pH water plays the role of a catalyst. 72 Very recently, Bomon et al 73 investigated the demethylation of differently functionalized guaiacol derivatives under similar conditions. Experiments were conducted with aqueous HCl at 250 °C under a N 2 atmosphere for 3 hours.…”

Selective Biocatalytic Defunctionalization of Raw Materials

“…[45] A sequence of two consecutive catalytic defunctionalization reactions, an O-and a C-dealkylation reaction, has been used for an efficient conversion, using Brønsted acids as catalysts, of biobased ferulic acid to catechol, which is mainly produced via the fossil-based route by hydroxylation of phenol. [46] The use of strong acids as catalysts, as well as high temperatures and pressures, may however be limiting regarding the reaction scope, selectivity, and in case of more sensitive compounds. Therefore, the opportunity to utilize selective yet broadly applicable catalysts able to work under mild reaction conditions is key for overcoming selectivity problems.…”

“…Controlled chemocatalytic defunctionalization of biobased amino acids and citric acid is of interest for the selective removal of amino or hydroxy groups [45] . A sequence of two consecutive catalytic defunctionalization reactions, an O ‐ and a C ‐dealkylation reaction, has been used for an efficient conversion, using Brønsted acids as catalysts, of biobased ferulic acid to catechol, which is mainly produced via the fossil‐based route by hydroxylation of phenol [46] …”