A green and efficient route to triarylphosphines via C–P cross-coupling reactions catalyzed by MWCNTs/MNPs–Bis(Py)/Tu–Pd(0) nanocomposite

We report an efficient and sustainable synthesis of triarylphosphines using a novel heterogeneous catalyst: palladium(0) supported on multi-walled carbon nanotubes and magnetic nanoparticles functionalized with bis(pyridyl) thiosemicarbazone ligands (MWCNTs/MNPs–Bis(Py)/Tu–Pd(0)). The catalytic system delivers high activity, achieving up to 94 % isolated yield of triphenylphosphane in a short time (2 h) under mild conditions (80 °C, KOAc, 2-MeTHF). Relative to existing methods, the approach offers faster reactions, higher yields, milder and greener reaction conditions, and enhanced operational simplicity. The use of 2-MeTHF as a green solvent and KOAc as a benign base reinforces the method's environmental credentials. Magnetic nanoparticles enable straightforward magnetic separation and excellent recyclability over multiple cycles with negligible performance loss. The superior activity arises from a combination of high surface area and efficient Pd(0) dispersion, reinforced by strong metal–ligand coordination from the Bis(Py)/Tu ligands on the functionalized MWCNT/MNP support. Comprehensive catalyst characterization—including FT-IR, TEM, VSM, and XRD supports a robust structure–function relationship and a classical Pd(0)/Pd(II) catalytic cycle involving oxidative addition, phosphine coordination, deprotonation where applicable, and reductive elimination to furnish the target triarylphosphine. Demonstrated across twenty substrate examples (72–97 % yields) with eight consecutive reuse cycles and minimal activity decline, this Pd(0) on MWCNTs/MNPs–Bis(Py)/Tu catalyst represents a cost-effective, green, and scalable platform for triphenylphosphane synthesis with broad applicability in organic synthesis and industrial catalysis.