Ultrasound-assisted solvent-free synthesis of 3, 4-dihydropyrimidin-2(1H)-ones/thiones using polyindole as a recyclable catalyst

Gold Nanoparticles‐electrochemically Reduced Graphene Oxide/Poly(indole‐5‐carboxylic acid) Nanocomposite for Electrochemical Non‐enzymatic Sensing of Hydrogen Peroxide

“…The crystal properties of the (a) P(In‐5‐COOH) and (b) AuNPs‐ERGO/P(In‐5‐COOH) are evaluated by XRD, and the spectra of these materials are shown in Figure S4. The P(In‐5‐COOH) exhibited the prominent peaks at approximately 2θ=8.2°, 20.9°, 26,3°, 39.9°, 46.5°, and 67.9° [41–44]. The distinct peaks of Au and ERGO, along with the peaks of P(In‐5‐COOH) were observed in the spectrum of AuNPs‐ERGO/P(In‐5‐COOH).…”

Greener organic synthetic methods: Sonochemistry and heterogeneous catalysis promoted multicomponent reactions

“… Entry Catalyst Conditions a Examples Yields (%) Ref. 1 NDL 5 EtOH:H 2 O, 30–45 min, 45–50 °C 13 c 82-97 d [131] 2 Polindole s.f b , 20–37 min, 45 °C 18 90–97 [132] 3 SBA-15/SO 3 H 25 min, r.t. 17 88–97 [121] 4 Fe–Cu/ZSM-5 H 2 O, 5 min, r.t. 9 e 92-97 f [120] 5 Dendrimer-PWA 5–15 min, 50 °C 18 88–97 [133] *Ultrasonication parameters: Entry 1. Ultrasonic bath with built-in heating, 45–50 °C; frequency: 35 kHz; power: 160/640 W. Entry 2. frequency: 33 kHz; power: 100 W, further details were not provided.…”

“…Attracted by the interest in conducting polymers, the Handore group [132] has successfully developed a new approach promoted by a highly stable heterogeneous catalyst polyindole to synthesize a set of DHMP derivatives in a solvent-free reaction ( Table 5 , Entry 2). The ultrasound parameters informed were frequency of 33 kHz and power of 100 W. During the optimization, the catalytic potential of other conducting polymers was analyzed in separate with the use of ultrasound, but the polyindole (1.5 w/w %) showed superior catalytic activity, providing the achievement of DHMPs with high yields and a short reaction time.…”

Polyaniline Decorated TiO2 nanocomposite as Efficient Catalyst for Ultrasound Synthesis of Dihydropyrimidinones.

“…Various reusable conducting polymeric material are used as a catalyst such as polyaniline [9] and polyaniline nanocomposite for electrochemical water splitting and dyes degradation [10]. Polyindole and nanocomposite shows best catalytic, antibacterial activity [12][13][14][15][16][17] and anticorrosive properties [18][19]. Polymer nanocomposites can also be used as textiles [20].…”