Synthesis of novel pyrrole derivatives from the multicomponent reaction using the new N-sulfonic acid modified poly (styrene-diethylenetriamine) as a solid acid catalyst

An efficient acid-catalyzed synthesis of 1,5-diaryl-3-(arylamino)-1H-pyrrol-2(5H)-ones is reported using novel N-sulfonic acid modified poly (styrene-diethylenetriamine) through three-component reaction between aldehyde, amine, and ethyl pyruvate in high yields and short times. This heterogeneous solid catalyst is produced by reacting amine-modified chloromethyl polystyrene with neat chlorosulfonic acid. The structure of the synthesized catalyst was examined with Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), dynamic light scattering (DLS), thermogravimetric analysis (TGA), differential thermal analysis (DTA), scanning electron micrograph (SEM), Brunauer–Emmett–Teller (BET), energy dispersive spectroscopy (EDS), and elemental analyses. The heterogeneous catalyst has many advantages, including an easy work-up procedure, a high product yield, and the capability to be easily regenerated and reused for at least five cycles without losing its activity.     

Tuning the Photocatalytic Performance of Ruthenium(II) Polypyridine Complexes Via Ligand Modification for Visible-Light-Induced Phosphorylation of Tertiary Aliphatic Amines

Tuning the redox potential of commonly available photocatalyst to improve the catalytic performance or expand its scope for challenging synthetic conversions is an ongoing demand in synthetic chemistry. Herein, the excited state properties and redox potential of commercially available [Ru(bpy)₃]²⁺ photocatalyst were tuned by modifying the structure of the bipyridine ligands with electron-donating/withdrawing units. The visible-light-mediated photoredox phosphorylation of tertiary aliphatic amines was demonstrated under mild conditions. A series of cross-dehydrogenative coupling reactions were performed employing the Ru^II complexes as photocatalyst giving the corresponding α-aminophosphinoxides and α-aminophosphonates via carbon-phosphorus (C−P) bond formation.