Isinglass–palladium as collagen peptide–metal complex: a highly efficient heterogeneous biocatalyst for Suzuki cross-coupling reaction in water

The class of bio-nanocatalysts (BNCs) is an evolving innovation that synergistically assimilates advanced nanotechnology with biotechnology. BNCs promote green processes due to their low consumption of chemicals and the absence of toxic by-products. Isinglass (IG), from the Dutch huizenblaas (sturgeon bladder), containing approximately 98% protein collagen, is used to support the immobilization of palladium (Pd) nanoparticles. This process leads to Pd/IG composite, a new class of heterogeneous collagen peptides–metal BNCs that exhibit high catalytic activity and reusability for ligand-free Suzuki coupling reaction in water. Additionally, these BNCs are obviously active in the cross-coupling reaction between acid chloride and arylboronic acid, producing a high yield of the desired ketones. The synthesized BNCs are well-characterized by Fourier transform infrared spectroscopy, field emission scanning electron microscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, inductively coupled plasma, and transmission electron microscopy.