Durable Heterogeneous Pd‐PNP Pincer Complex for CarbonCarbon Bond Formation in Continuous‐Flow Systems

Carbon Bond Formation in Continuous-Flow Systems"/>

Pd-SCORPI, a durable heterogeneous PNP-pincer palladium catalyst immobilized on Merrifield resin, promotes sustainable flow synthesis by providing high operational stability and minimal palladium leaching, thereby reducing metal waste. The Mizoroki–Heck reaction maintains yields exceeding 92% over 300  h, while the Suzuki–Miyaura flow protocol affords a 91% yield over 150 h.

A durable PNP pincer catalyst, designated “Pd-SCORPI”, is developed and prepared by immobilizing a bis(diphenylphosphinoethyl)amine-Pd complex onto Merrifield resin. The heterogeneous catalyst demonstrates notable stability in continuous-flow carboncarbon coupling reactions. For the Mizoroki–Heck benchmark (4–iodoanisole and n–butyl acrylate in DMF, 120 °C, 0.05 mL min^{− 1}), Pd–SCORPI delivers a turnover number (TON) of 1115 and a turnover frequency (TOF) of 3.32 h^{− 1} while sustaining over 92% conversion for 14 days. Substrate scope analysis highlights the versatility of the catalyst, as aryl halides bearing electron-donating groups (EDGs) and electron-withdrawing groups (EWGs) couple efficiently with diverse alkenes,including challenging substrates such as acrylic acid and acrylamide derivatives. In the Suzuki–Miyaura flow protocol (4'–iodoacetophenone and phenylboronic acid in 1 : 3 H₂O/1,4–dioxane, ambient temperature, 0.05 mL min^{− 1}), Pd–SCORPI achieves a 91% isolated yield, a TON of 1242, and stable operation for 150 h. This investigation highlights the potential of Pd-SCORPI in advancing green chemistry by minimizing waste, enhancing catalyst recyclability, and promoting efficient and sustainable chemical processes, thus paving the way for scalable industrial applications.

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