Synthesis of spiroindoline derivatives and biphenyl compounds in green solvent via a "capture-release" mechanism using modified polyacrylonitrile fiber as a catalyst

Green synthesis of critical bioactive molecules and fine chemicals is attracting increasing interest. This study investigates the use of two distinct functionalized polyacrylonitrile (PAN) fibers (PANEDBPF and PANEDBP-Pd effective catalysts in a green solvent comprising ethanol and water. Firstly, a PAN fiber was modified using 2(diphenylphosphino) ethylamine, a strongly nucleophilic phosphine compound, to obtain PANEDBPF. Spiroindoline derivatives were obtained in 98 % yields when the reaction was conducted using 5 mol% of PANEDBPF as the catalyst at 70 degrees C for 30 min. Next, we loaded PdNPs onto PANEDBPF to obtain PANEDBP-Pd Suzuki coupling reaction was conducted at room temperature (25 degrees C) using 0.5 mol% of PANEDBP-Pd 0 F, the products were obtained in an extremely high yield of 99 %. Additionally, the unique enrichment of the substrate by the functionalized fibers during the reaction and the subsequent release of the product from the microenvironment conform to the "capture-release" reaction mode of catalysis. Both PANEDBPF and PANEDBP-Pd demonstrated good gram-scale amplification, repeatability, catalytic activity, and stability. Hence, they are highly promising candidates for green chemistry applications.