Excellence in Acrylation - Scope and Limitation of Glucosyl Imidazolium-coated Novozym 435 Catalyzed (Meth)acryl Ester Synthesis

The incorporation of carbohydrate based ionic liquids as a support for Novozym 435 was previously studied by the authors for the acrylation of n-butanol as the target substrate, which was used as the foundation for the design of experiments. The combination of carbohydrate based ionic liquids and Novozym 435 remains a key aspect of this work. Building upon this, the reaction parameters were optimized for the Novozym catalyst. Substrate screening was performed to explore the scope and limitations of room temperature acrylation reactions. Herein, different alcohols and reaction conditions were screened extensively for the different acrylate products with yields of up to 99.9 % determined via gas chromatography (GC). Standard straight chain alcohols, 2-functionalized ethanol derivatives with electron donating and withdrawing groups, and more sterically challenging substrates were investigated over a broad concentration region. To further underline the applicability of the modified biocatalyst, two alcohols were converted with methacrylic acid. The presented method offers a greener pathway for acrylate synthesis, which eliminates the need for high reaction temperatures, strongly acidic catalysts and/or polymerization inhibitors as used in non-biocatalytic acrylate synthesis. In this work we used our previously developed Novozym 435 biocatalyst coated with a glucose-based imidazolium salt to investigate the scope of biocatalytic acrylations. The reaction conditions of acid concentration and alcohol excess were screened extensively for each substrate, leading to high yields or full conversion for most the (meth)acrylic esters.image

Automated summary

This study investigates the use of carbohydrate based ionic liquids as a support for Novozym 435 in acrylation reactions. By optimizing reaction parameters and screening different substrates, the researchers explore the scope and limitations of room temperature acrylation reactions, achieving high yields of acrylate products.