# Naphthalene-Based Polymers as Catalytic Supports for Suzuki Cross-Coupling
## 5 Conclusions  
In this study, we showed that NA-based HAPs can be easily synthesized by one-stage Friedel-Crafts crosslinking. NA units can be functionalized with -OH, -SO\({}_{3}\)H, and -NO\({}_{2}\) groups, and the synthesized HAPs can be used as supports for Pd-containing catalysts active in Suzuki cross-coupling. All the NA-based polymers contain about 4-6 at.% of the oxygen on the surface. Introduction of oxygen-containing functionalities improves the distribution and sizes of Pd NPs. Moreover, these functionalities can increase surface hydrophilicity, improving catalytic stability of Pd-HAPs in the Suzuki reaction. Synthesized NA-based HAPs cannot fully prevent Pd leaching and the loss of catalytic activity at reuses due to the homogeneous/heterogeneous mechanism of the Suzuki reaction. However, we believe that the presented data can be useful for a better understanding of structure-properties relationships for polymer-based Pd catalysts and may find applications in other processes. **Supplementary Materials:** The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/molecules28134938/s1](https://www.mdpi.com/article/10.3390/molecules28134938/s1)]([https://www.mdpi.com/article/10.3390/molecules28134938/s1](https://www.mdpi.com/article/10.3390/molecules28134938/s1)), Figure S1: Scope of aryl halides for 1%-Pd/SNA120 (1 mmol of aryl halide, 1.5 mmol of PBA, 2.0 mmol of NaOH, 60 \({}^{\circ}\)C, 900 rpm, 0.02 g of the catalyst); Figure S2: Bright-field STEM (scale 100 nm) (a,b) and HAADF STEM (scale 200 nm) (c) images of the sample 1%-Pd/NL60 taken after the second use in Suzuki reaction and EDX mapping of Pd (d), O (e), and Cl (f); Figure S3: Bright-field STEM (scales 100 and 20 nm) (a,b) and HAADF STEM (scale 30 nm) (c) images of the sample 1%-Pd/NNA120 taken after the second use in Suzuki reaction and EDX mapping of Pd (d), O (e), Cl (f), and Na (g); Figure S4: Bright-field STEM (scales 100 and 500 nm) (a,b) and HAADF STEM (scale 30 nm) (c) images of the sample 1%-Pd/SNA120 taken after the second use in Suzuki reaction and EDX mapping of Pd (d), O (e), Cl (f), and Na (g); Figure S5: Correlation between the activity and stability in the second run on the sizes of Pd NPs formed during the second run in the initial (unreduced) samples (1 mmol of BrAN, 1.5 mmol of PBA, 2.0 mmol of NaOH, 60 \({}^{\circ}\)C, 900 rpm, 0.02 g of the catalyst); Figure S6: Bright-field STEM images of 1%-Pd/NL60-R taken after the second use in Suzuki reaction (scale 100 nm) (a), 1%-Pd/SNA120-R (b) and 1%-Pd/NNA120-R(c) both taken after the third use in Suzuki reaction (scale 50 nm); Figure S7: HAADF STEM image (scale 200 nm) (a) of the sample 1%-Pd/NNA120-R taken after the third use in Suzuki reaction and EDX mapping of Pd (b), O (c),Na (d), Cl (e), and Br (f); Figure S8: Hot-filtration test for 1%-Pd/NNA120-R (1 mmol of BrAN, 1.5 mmol of PBA, 2.0 mmol of NaOH, 60 \({}^{\circ}\)C, 900 rpm, 0.02 g of the catalyst), Table S1: Influence of aryl halide nature on the Suzuki cross-coupling in the presence of the catalyst1%-Pd/SNA120. **Author Contributions:** Conceptualization, L.Z.N. and A.V.B. ; methodology, L.Z.N. ; data curation, L.Z.N. ; validation, L.K.-M. and L.Z.N. ; investigation, E.S.B., A.V.B., M.E.M., Y.V.L., A.I.S. and V.P.M. ; formal analysis, E.S.B. ; resources, L.Z.N. ; writing--original draft preparation, E.S.B. and L.Z.N. ; writing--review and editing, L.K.-M.; visualization, L.Z.N. ; supervision, L.K.-M. and M.G.S. ; project administration, L.Z.N. ; funding acquisition, L.Z.N. All authors have read and agreed to the published version of the manuscript. **Funding:** This research was funded by the Russian Science Foundation, grant number 23-29-00604. **Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable. Data Availability Statement: Data sharing is not applicable to this article. The authors highly appreciate the preparation of the catalysts by [PERSON].