## Discussion  
### Preparation of the TBTA Monomer and Supported Catalysts  
Because neither the mechanical properties of the commercial resin **P2** (large swelling in most solvents [17]) nor the published synthetic route for its preparation appeared to satisfy the requirements of continuous-flow large-scale applications, both aspects had to be addressed in the present study. \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Entry*** & **Device** & **R1**, **R2** & **S/C3** & **Solvent** & **Axalied** & \(\phi\) & **r** & **Yield** & **STY** & **Cu** \\ \hline  & & & & (r/s) & **(M)** & **(mL h-1)*** & **(min)** & **(s)*** & **(s-1)*** & **(s-1)*** & **(s-1)*** \\ \hline
1\({}^{\text{h}}\) & **R1** & Ph, CH\({}_{3}\)OH & 347 & MeOH/THF (4/1) & 0.20 & 0.6–18 & 11–32 & 88\({}^{\text{i}}\) & 63 & - \\
2 & **R1** & Ph, CH\({}_{3}\)OH & 178 & MeOH/THF (3/2) & 0.20 & 0.6– 32 & 49 & 64 & - \\
3\({}^{\text{h}}\) & **R2** & Ph, CH\({}_{3}\)OH & 349 & MeOH/CH\({}_{3}\)OH (4/1) & 0.21 & 0.6–18 & 13–22 & 68\({}^{\text{i}}\) & 63 & - \\
4 & **R2** & Ph, Ph= Bu & 174 & MeOH/THF (4/1) & 0.20 & 0.6– 18 & 13–22 & 39 & 71 & 138 \\
5 & **R3** & Ph, CH\({}_{3}\)OH & 71 & MeOH/THF (4/1) & 0.20 & 0.6– 18 & 13–22 & 68\({}^{\text{i}}\) & 63 & - \\
6 & **R3** & Ph, CH\({}_{3}\)OH & 71 & MeOH/THF (4/1) & 0.20 & 0.6– 18 & 13–22 & 39 & 71 & 138 \\
7 & **R3** & Ph, CH\({}_{3}\)OH & 71 & MeOH/THF (4/1) & 0.20 & 0.6– 18 & 13–22 & 64\({}^{\text{h}}\) & 175 \\
8 & **R3** & Ph, CH\({}_{3}\)OH & 70 & MeOH/THF (4/1) & 0.20 & 0.6– 32 & 91 & 64 & 175 \\
9 & **R4** & Ph, CH\({}_{3}\)OH & 72 & MeOH/THF (4/1) & 0.20 & 0.6– 32 & 92 & 68 & - \\
10 & **R4** & Ph, CH\({}_{3}\)OH & 71 & MeOH/THF (4/1) & 0.21 & 0.6– 32 & 78\({}^{\text{i}}\) & 80 & - \\
11 & **R4** & Ph, CH\({}_{3}\)OH & 73 & MeOH/THF (4/1) & 0.21 & 0.6– 32 & 96 & 82 & 148 \\
12 & **R5** & Ph, CH\({}_{3}\)OH & 74 & MeOH/THF (4/1) & 0.18 & 0.6– 32 & 83\({}^{\text{i}}\) & 131 & - \\
13 & **R5** & Ph, CH\({}_{3}\)OH & 74 & MeOH/THF (4/1) & 0.21 & 0.6– 32 & 95 & 250 & - \\
14 & **R5** & Ph, CH\({}_{3}\)OH & 74 & MeOH/THF (4/1) & 0.18 & 0.6– 32 & 90 & 69 & - \\
15 & **R5** & Ph, CH\({}_{3}\)OH & 74 & MeOH/THF (4/1) & 0.21 & 0.6– 32 & 97 & 125 & 853 \\
16 & **R5** & Ph, CH\({}_{3}\)OH & 74 & MeOH/THF (4/1) & 0.26 & 0.3– 32 & 60\({}^{\text{m}}\) & 249 & 257 \\ \hline \hline \end{tabular}  
\({}^{\text{a}}\) Conditions: 1 equiv. azide per alkyne group, 1 mol% sodium l-ascorbate, and 15–50 mg each of \(n\)-nonane and biphenyl internal standards, in 5–25 mL of the indicated solvent mixture. \({}^{\text{b}}\) Ratio \(n_{\text{radio}}/n_{\text{Cu}}\) at the end of the run, calculated on the basis of the initial copper content in the reactor (14 μm). \({}^{\text{c}}\) Flow-rate. \({}^{\text{d}}\) Estimated average residence time of the reactants in the catalyst-filled section. \({}^{\text{e}}\) Isolated yield after evaporation of the volatiles or column chromatography. \({}^{\text{f}}\) Space-time yield. \({}^{\text{g}}\) Copper content in the dried crude shown by ICP-OES. \({}^{\text{h}}\) Reactions carried out in a glove-bag filled with N\({}_{2}\). \({}^{\text{l}}\) Conversion extent of the azide shown by GC-MS. \({}^{\text{l}}\) Reactor already used in the previous run. \({}^{\text{h}}\) The 1,2,3-triazole product precipitates inside the reactor. \({}^{\text{l}}\) As a 1.7:1 mixture of mono- and bis-triazole products. \({}^{\text{m}}\) As a 3.4:1 mixture of mono- and bis-triazole products. \({}^{\text{m}}\) As a 3.4:1 mixture of mono- and bis-triazole products.  
\end{table} 
Table 3: Continuous-flow CuAAC reactions in the PCFRs containing **P7**-CuSO\({}_{4}\) reduced with sodium l-ascorbate. As for the polymer support, a highly cross-linked architecture was selected in order to minimize clogging problems in flow, due to excessive swelling of the support.