Paal–Knorr synthesis of pyrroles: from conventional to green synthesis

Balakrishna, A.; Aguiar, António; Sobral, Pedro J. M.; Wani, Mohmmad Younus; Silva, Joana Almeida e; Sobral, A. J. F. N.

doi:10.1080/01614940.2018.1529932

Cited by 83 publications

(29 citation statements)

References 116 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Encouraged by these results, we went on exploring the potential of our 1,4-diketones in a Paal-Knorr synthesis of pyrroles. 17 Gratifyingly, the treatment of 4c, 4d and 4o with aniline in isopropanol at 80 C allowed to prepare azulene-dihydroindol-4-one conjugates 7ac in moderate to good yields (Scheme 3). The molecular structure of representative azulene-dihydroindol-4-one derivative 7b has been resolved through the X-ray crystallographic analysis (Fig.…”

Section: Resultsmentioning

confidence: 99%

Three-component reaction of azulene, aryl glyoxal and 1,3-dicarbonyl compound for the synthesis of various azulene derivatives

Gong

Peshkov

et al. 2020

RSC Adv.

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 99%

Three-component reaction of azulene, aryl glyoxal and 1,3-dicarbonyl compound for the synthesis of various azulene derivatives

Gong

Peshkov

et al. 2020

RSC Adv.

View full text Add to dashboard Cite

show abstract

“…In 1999, Demirayak and coworkers [24] synthesised six 5-nitroimidazole/pyrrole hybrids of general formula 2 in yields ranging from 63 to 83% by reaction of 2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethan-1-amine dihydrochloride (3) with equimolar amounts of the appropriate 1,4-diones, i.e., compounds 4, 5, and 6a-d, and 2 eq of AcONa in AcOH under reflux for 0.5 h, under the conventional Paal-Knorr pyrrole synthesis conditions [25] (Scheme 1). The mechanism of action 1 and other nitroimidazoles involves the conversion of this prodrug, via an anaerobic 1-electron reduction of the nitro group, to a short-lived nitro radical anion, which is unstable and decomposes to give a nitrite anion and an imidazole radical.…”

Section: Heterocyclic Conjugates and Hybrids Bearing Nitroimidazole Moietymentioning

confidence: 99%

An Updated Review on the Synthesis and Antibacterial Activity of Molecular Hybrids and Conjugates Bearing Imidazole Moiety

Rossi

Ciofalo

2020

Molecules

View full text Add to dashboard Cite

The rapid growth of serious infections caused by antibiotic resistant bacteria, especially the nosocomial ESKAPE pathogens, has been acknowledged by Governments and scientists and is one of the world’s major health problems. Various strategies have been and are currently investigated and developed to reduce and/or delay the bacterial resistance. One of these strategies regards the design and development of antimicrobial hybrids and conjugates. This unprecedented critical review, in which our continuing interest in the synthesis and evaluation of the bioactivity of imidazole derivatives is testified, aims to summarise and comment on the results obtained from the end of the 1900s until February 2020 in studies conducted by numerous international research groups on the synthesis and evaluation of the antibacterial properties of imidazole-based molecular hybrids and conjugates in which the pharmacophoric constituents of these compounds are directly covalently linked or connected through a linker or spacer. In this review, significant attention was paid to summarise the strategies used to overcome the antibiotic resistance of pathogens whose infections are difficult to treat with conventional antibiotics. However, it does not include literature data on the synthesis and evaluation of the bioactivity of hybrids and conjugates in which an imidazole moiety is fused with a carbo- or heterocyclic subunit.

show abstract

“…e Bi 2 SiO 5 /TiO 2 displayed excellent catalytic activities in gasphase epoxidation to propylene oxide by molecular oxygen [177]. Bi 2 Cl 3 /SiO 2 might also act as a very effective and ecofriendly heterogeneous Lewis acid catalyst during the synthesis of the Paal-Knorr pyrrole in hexane at room temperature [178][179][180][181].…”

Section: Bismuth Compounds' Good Catalytic Success Towardmentioning

confidence: 99%

Bismuth as Smart Material and Its Application in the Ninth Principle of Sustainable Chemistry

Odularu

2020

Journal of Chemistry

View full text Add to dashboard Cite

This paper reports an overview of Green Chemistry and the concept of its twelve principles. This study focusses on the ninth principle of Green Chemistry, that is, catalysis. A report on catalysis, in line with its definition, background, classification, properties, and applications, is provided. The study also entails a green element called bismuth. Bismuth’s low toxicity and low cost have made researchers focus on its wide applications in catalysis. It exhibits smartness in all the catalytic activities with the highest catalytic performance among other metals.

show abstract

Paal–Knorr synthesis of pyrroles: from conventional to green synthesis

Cited by 83 publications

References 116 publications

Three-component reaction of azulene, aryl glyoxal and 1,3-dicarbonyl compound for the synthesis of various azulene derivatives

Three-component reaction of azulene, aryl glyoxal and 1,3-dicarbonyl compound for the synthesis of various azulene derivatives

An Updated Review on the Synthesis and Antibacterial Activity of Molecular Hybrids and Conjugates Bearing Imidazole Moiety

Bismuth as Smart Material and Its Application in the Ninth Principle of Sustainable Chemistry

Contact Info

Product

Resources

About