ZnO nanorods as efficient catalyst for the green synthesis of thiophene derivatives: Investigation of antioxidant and antimicrobial activity

Abstract

In this work, thiophene derivatives were synthesized in good yields via multicomponent reaction of isoquinoline, alkyl bromides, activated acetylenic compounds, isothiocyanates, and catalytic amounts of ZnO nanorods (NRs) at room temperature under solvent‐free conditions. This procedure for the synthesis of thiophene derivatives is green, easy, and simple with excellent yield. In addition, DPPH radical scavenging and ferric reduction power experiment has been studied for the evaluation of the antioxidant activity of some prepared thiophenes, for example, 5b, 5d, 5e, and 5f. As outcome, the compound 5d exhibited a noteworthy radical trapping activity and excellent reducing ability than synthetic antioxidants such as butylated hydroxytoluene (BHT) and 2‐tertbutylhydroquinone (TBHQ). Moreover, the antimicrobial activity of some synthesized thiophenes was confirmed by employing the disk diffusion test on Gram‐positive and Gram‐negative bacteria. The obtained results of disk diffusion test showed that compounds 5b, 5d, 5e, and 5f prevented bacterial growth.

Zinc Oxide Nanoparticles as Efficient Heterogeneous Catalyst for Synthesis of Bio‐active Heterocyclic Compounds

“…N. Faal Hamedani et al in 2019 reported ZnO-NRs as an efficient catalyst for the greener synthesis of thiophene derivatives (220), with the assistance of a multi-component reaction which includes isoquinoline (210), alkyl bromides (28), activated acetylenic (218) substances, isothiocyanates (219), and catalytic amount of ZnO-NR catalyst derivative of thiophene were synthesized in good yields (Scheme 44). [192] To produce the thiophene derivatives (220), initially, abstraction of hydrogen take places when isoquinoline salt ( 210 12. Synthesis of spiro heterocyclic derivatives N. Satish Kumar et al reported a synthesis of novel dispiroindolizidine bisoxindoles by using ZnO-NPs in an aqueous solution.…”

“…in 2019 reported ZnO‐NRs as an efficient catalyst for the greener synthesis of thiophene derivatives ( 220 ), with the assistance of a multi‐component reaction which includes isoquinoline ( 210 ), alkyl bromides ( 28 ), activated acetylenic ( 218 ) substances, isothiocyanates ( 219 ), and catalytic amount of ZnO‐NR catalyst derivative of thiophene were synthesized in good yields (Scheme 44). [192] To produce the thiophene derivatives ( 220 ), initially, abstraction of hydrogen take places when isoquinoline salt ( 210 ), ZnO‐NR, and triethylamine were reacted and formed intermediate ( 222 ) as the nucleophile. Intermediate ( 223 ) generated from the nucleophilic attack of intermediate ( 222 ) and compound ( 218 ) reacted with isothiocyanate ( 219 ) to form intermediate ( 224 ).…”

Thiophene‐containing compounds with antimicrobial activity

“…A multicomponent reaction between acetylenedicarboxylic esters, aryl isothiocyanates, isoquinoline and either phenacyl bromides or ethyl bromopyruvate in the presence of ZnO nanorods provided easy access to compounds 131 in one step with good yields. [115] With respect to their antibacterial activity, which was established using the…”

“…A multicomponent reaction between acetylenedicarboxylic esters, aryl isothiocyanates, isoquinoline and either phenacyl bromides or ethyl bromopyruvate in the presence of ZnO nanorods provided easy access to compounds 131 in one step with good yields. [ 115 ] With respect to their antibacterial activity, which was established using the disc diffusion technique, four thiophenes 131 were more potent than streptomycin, while only two of them were at the same time more potent than gentamicin against S. aureus . Compound 131 (R = CH 3 ; R 1 = COOC 2 H 5 ; Ar = 4‐CH 3 C 6 H 4 ) was inactive and other two 2‐arylaminothiophenes 131 had a poor activity against the same bacterial strain.…”

Use of Dialkyl Acetylenedicarboxylates in the Multicomponent Synthesis of Heterocyclic Structures

“…(Scheme 26). [51] Coupling of thiopyrano [52] Scheme 20. Suggested mechanism for synthesis of furanone derivatives 46.…”