Synthesis of Bifunctional Molecules for the Production of Polymers Based on Unsaturated Fatty Acids as Bioderived Raw Materials

Abstract

Currently, investigations of polymer-building blocks made from biorenewable feedstocks such as, for example, fatty acids, are of high interest for the chemical industry. An alternative synthesis of nitrile-substituted aliphatic carboxylic acids as precursors for ω-amino acids, which are useful to produce polymers, was investigated starting from biorenewable fatty acids. By hydroformylation of unsaturated fatty acids or unsaturated acids being accessible from unsaturated fatty acids by cross-metathesis reactions, aldehydes are formed. In this work, the hydroformylation of such unsaturated acids led to the formation of the corresponding aldehydes, which were afterwards converted with hydroxylamine to aldoximes. Subsequent dehydration by an aldoxime dehydratase as a biocatalyst or by CuII acetate led to the desired nitriles. Within this work, C7-, C9- and C11-carboxylic acids with a terminal nitrile functionality as well as a branched nitrile-functionalized stearate derivative were synthesized by means of this approach. As these nitriles serve as precursors for amino acids being suitable for polymerization, this work represents an alternative synthetic access to polyamide precursors, which starts directly from unsaturated fatty acids as biorenewable resources and avoids harsh reaction conditions as well as and by-product formation.

Advances in One-Pot Chiral Amine Synthesis Enabled by Amine Transaminase Cascades: Pushing the Boundaries of Complexity

“…With the increased demand for biomass-derived starting materials, fatty acid biotransformation has become important for recent research efforts. − Fatty acids are suitable starting points for the generation of long-chain aliphatic amines and esters . Using the whole-cell cascade reaction approach, various long-chain aliphatic amines such as ( S , Z )-hepta-dec-9-en-7-amine and 9-aminoheptadecane were synthesized from ricinoleic acid and oleic acid.…”

Nitrile Synthesis with Aldoxime Dehydratases: A Biocatalytic Platform with Applications in Asymmetric Synthesis, Bulk Chemicals, and Biorefineries

“…Aspects related to how to address the temperature difference of the reactions (heating/cooling) and downstream together with the heat integration remain as exciting challenges to be considered for a closed-loop practical application. Analogous cascade processes have been reported by combining (biogenic) fatty acids with cross-metathesis, hydroformylation, and use of aldoxime dehydratases to afford difunctionalized nitrile fatty acids that can find applications in polymer chemistry [ 28 ].…”

Synthetic Processes toward Nitriles without the Use of Cyanide: A Biocatalytic Concept Based on Dehydration of Aldoximes in Water

“…Furthermore, Oxd enzymes have also been successfully applied in the synthesis of terminal aliphatic nitriles bearing a carboxylic acid moiety as a further functional group (Scheme 9). [51] Such bifunctional molecules are of interest for polymer production because the nitrile group can be subsequently converted into an amino moiety by means of hydrogenation, thus furnishing ω‐amino‐substituted fatty acids as monomers for polyamides.…”

“… Chemoenzymatic synthesis of terminal aliphatic nitriles bearing a carboxylic acid moiety by using OxdB as a biocatalyst [51] …”