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M. O. Pretscher, T. Chen, G. Sitaru, S. Gekle, J. Ji, S. Agarwal

Chem., 2019.

We show precise and direct two‐dimensional (2D) printing of the incompatible polymer acid‐base catalysts and their utility in one‐pot two‐step reactions. Multi‐step catalytic reactions using incompatible catalysts in a one‐pot reaction cascade require special methods and materials for isolation of catalysts from each other. This, in general is a tedious process requiring special polymer architectures as catalysts’ carrier for preserving the activity of otherwise incompatible catalysts. We propose the immobilization of incompatible polymer catalysts, such as polymer acid and base catalysts, on a substrate in variable sizes and amounts by precise 2D printing. The copolymers with a basic (4‐vinylpyridine) and acidic (styrene sulfonic acid) functionality and methacryloyl benzophenone as a UV cross‐linking unit were used for 2D printing. The printed meshes were immersed together in a reaction solution containing (dimethoxy methyl)‐benzene and ethyl cyanoformate, resulting in a two‐step acid‐base catalyzed cascade reaction, i.e. deacetalization followed by carbon‐building reaction. The time‐dependent consumption of (dimethoxymethyl)‐benzene to the intermediate benzaldehyde and the product was monitored, and a kinetic model was developed to investigate the underlying reaction dynamics. The complexity of multi‐step Wolf‐Lamb‐type reactions was generally significantly decreased using our approach due to the easy polymerization and immobilization procedure.