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Topics in Current Chemistry (Cham) Jan 2023The incorporation of aryl substituents at the meso-positions of calix[4]pyrrole (C4P) scaffolds produces aryl-extended (AE) and super-aryl-extended (SAE)... (Review)
Review
The incorporation of aryl substituents at the meso-positions of calix[4]pyrrole (C4P) scaffolds produces aryl-extended (AE) and super-aryl-extended (SAE) calix[4]pyrroles. The cone conformation of the all-α isomers of "multi-wall" AE-C4Ps and SAE-C4Ps displays deep aromatic clefts or cavities. In particular, "four-wall" receptors feature an aromatic polar cavity closed at one end with four convergent pyrrole rings and fully open at the opposite end. This makes AE- and SAE-C4P scaffolds effective receptors for the molecular recognition of negatively charged ions and neutral guest molecules with donor-acceptor and hydrogen bonding motifs. In addition, adequately functionalized all-α isomers of multi wall AE- and SAE-C4P scaffolds self-assemble into uni-molecular and supra-molecular aggregates displaying capsular and cage-like structures. The self-assembly process requires the presence of template ions or molecules that lock the C4P cone conformation and complementing the inner polar functions and volumes of their cavities. We envisioned performing an in-depth revision of AE- and SAE-C4P scaffolds owing to their importance in different domains such as supramolecular chemistry, biology, material sciences and pharmaceutical chemistry. Herewith, besides the synthetic details on the elaboration of their structures, we also draw attention to their diverse applications. The organization of this review is mainly based on the number of "walls" present in the AE-C4P derivatives and their structural modifications. The sections are further divided based on the C4P functions and applications. The authors are convinced that this review will be of interest to researchers working in the general area of supramolecular chemistry as well as those involved in the study of the binding properties and applications of C4P derivatives.
Topics: Pyrroles; Porphyrins; Models, Molecular; Ions; Molecular Conformation
PubMed: 36607442
DOI: 10.1007/s41061-022-00419-0 -
Chemical Society Reviews Jul 2014Pyrrole is one of the most important one-ring heterocycles. The ready availability of suitably substituted and functionalized pyrrole derivatives is essential for the... (Review)
Review
Pyrrole is one of the most important one-ring heterocycles. The ready availability of suitably substituted and functionalized pyrrole derivatives is essential for the progress of many branches of science, including biology and materials science. Access to this key heterocycle by multicomponent routes is particularly attractive in terms of synthetic efficiency, and also from the environmental point of view. We update here our previous review on this topic by describing the progress made in this area in the period between mid-2009 and the end of 2013.
Topics: Heterocyclic Compounds; Pyrroles
PubMed: 24676061
DOI: 10.1039/c3cs60015g -
Chemical Society Reviews Nov 2010Multicomponent reactions are one of the most interesting concepts in modern synthetic chemistry and, as shown in this critical review, they provide an attractive entry... (Review)
Review
Multicomponent reactions are one of the most interesting concepts in modern synthetic chemistry and, as shown in this critical review, they provide an attractive entry into pyrrole derivatives, which are very important heterocycles from many points of view including medicinal and pharmaceutical chemistry and materials science (97 references).
Topics: Molecular Structure; Pyrroles; Stereoisomerism
PubMed: 20601998
DOI: 10.1039/b917644f -
Angewandte Chemie (International Ed. in... Dec 2018Herein we report the biocatalytic synthesis of substituted pyrazines and pyrroles using a transaminase (ATA) to mediate the key amination step of the ketone precursors....
Herein we report the biocatalytic synthesis of substituted pyrazines and pyrroles using a transaminase (ATA) to mediate the key amination step of the ketone precursors. Treatment of α-diketones with ATA-113 in the presence of a suitable amine donor yielded the corresponding α-amino ketones which underwent oxidative dimerization to the pyrazines. Selective amination of α-diketones in the presence of β-keto esters afforded substituted pyrroles in a biocatalytic equivalent of the classical Knorr pyrrole synthesis. Finally we have shown that pyrroles can be prepared by internal amine transfer catalyzed by a transaminase in which no external amine donor is required.
Topics: Molecular Structure; Pyrazines; Pyrroles; Transaminases
PubMed: 30335228
DOI: 10.1002/anie.201810555 -
Marine Drugs Sep 2021Nitrogen heterocycles are essential parts of the chemical machinery of life and often reveal intriguing structures. They are not only widespread in terrestrial habitats... (Review)
Review
Nitrogen heterocycles are essential parts of the chemical machinery of life and often reveal intriguing structures. They are not only widespread in terrestrial habitats but can also frequently be found as natural products in the marine environment. This review highlights the important class of marine pyrrole alkaloids, well-known for their diverse biological activities. A broad overview of the marine pyrrole alkaloids with a focus on their isolation, biological activities, chemical synthesis, and derivatization covering the decade from 2010 to 2020 is provided. With relevant structural subclasses categorized, this review shall provide a clear and timely synopsis of this area.
Topics: Alkaloids; Animals; Aquatic Organisms; Pyrroles; Structure-Activity Relationship
PubMed: 34564176
DOI: 10.3390/md19090514 -
Molecules (Basel, Switzerland) Mar 2023Pyrrole-2-carboxaldehyde (Py-2-C) derivatives have been isolated from many natural sources, including fungi, plants (roots, leaves, and seeds), and microorganisms. The... (Review)
Review
Pyrrole-2-carboxaldehyde (Py-2-C) derivatives have been isolated from many natural sources, including fungi, plants (roots, leaves, and seeds), and microorganisms. The well-known diabetes molecular marker, pyrraline, which is produced after sequential reactions in vivo, has a Py-2-C skeleton. Py-2-Cs can be chemically produced by the strong acid-catalyzed condensation of glucose and amino acid derivatives in vitro. These observations indicate the importance of the Py-2-C skeleton in vivo and suggest that molecules containing this skeleton have various biological functions. In this review, we have summarized Py-2-C derivatives based on their origins. We also discuss the structural characteristics, natural sources, and physiological activities of isolated compounds containing the Py-2-C group.
Topics: Molecular Structure; Glucose; Pyrroles; Fungi
PubMed: 36985566
DOI: 10.3390/molecules28062599 -
European Journal of Medicinal Chemistry Dec 2020The discovery of novel synthetic compounds with drug-like properties is an ongoing challenge in medicinal chemistry. Natural products have inspired the synthesis of... (Review)
Review
The discovery of novel synthetic compounds with drug-like properties is an ongoing challenge in medicinal chemistry. Natural products have inspired the synthesis of compounds for pharmaceutical application, most of which are based on N-heterocyclic motifs. Among these, the pyrrole ring is one of the most explored heterocycles in drug discovery programs for several therapeutic areas, confirmed by the high number of pyrrole-based drugs reaching the market. In the present review, we focused on pyrrole and its hetero-fused derivatives with anticancer, antimicrobial, and antiviral activities, reported in the literature between 2015 and 2019, for which a specific target was identified, being responsible for their biological activity. It emerges that the powerful pharmaceutical and pharmacological features provided by the pyrrole nucleus as pharmacophore unit of many drugs are still recognized by medicinal chemists.
Topics: Anti-Infective Agents; Antineoplastic Agents; Antiviral Agents; Drug Design; Humans; Molecular Targeted Therapy; Pyrroles
PubMed: 32916311
DOI: 10.1016/j.ejmech.2020.112783 -
Chemical Reviews Feb 2017A large number of porphyrinoids containing 2,2'-bipyrrole subunits have appeared since they were originally found as a component of sapphyrin and corrole, and it was... (Review)
Review
A large number of porphyrinoids containing 2,2'-bipyrrole subunits have appeared since they were originally found as a component of sapphyrin and corrole, and it was found that the bipyrrole subunit endowed macrocycles with specific geometric features and electronic properties. Synthetic methods for bipyrrole-containing precursors for porphyrinoid are summarized in this review; these include coupling reactions of pyrrole rings, pyrrole ring-forming reactions leading directly to bipyrrole units, and synthetic reactions for oligopyrrolic compounds. Some hybrid oligopyrroles having nonpyrrole (hetero)aromatic ring(s) are also included. This review also describes porphyrinoids composed of bipyrrole subunits. Interesting electronic properties derived from strong cyclo-π-conjugation are highlighted in the bipyrrole-based porphyrinoids with or without meso-like carbons. Anion-binding chemistry is one of the main topics for bipyrrole-based macrocycles with less efficient or deficient cyclo-π-conjugation, such as those linked with electronically localized aromatic ring(s), with sp carbon(s), and with amido or imine connection(s). The principal concern in this review is porphyrinoids of relatively large ring size, composed of more than five units of pyrroles and (hetero)aromatic substitutes in total, and so bipyrrole-based porphyrinoids up to five pyrrolic units, such as corroles, porphycenes, sapphyrins, and smaragdyrin, will not be covered here except for some special cases.
Topics: Crystallography, X-Ray; Molecular Conformation; Oxidation-Reduction; Porphyrins; Pyrroles
PubMed: 27802039
DOI: 10.1021/acs.chemrev.6b00430 -
Synthesis of Multiple-Substituted Pyrroles via Gold(I)-Catalyzed Hydroamination/Cyclization Cascade.Organic Letters Jun 2015A gold-catalyzed cascade hydroamination/cyclization reaction of α-amino ketones with alkynes to form substituted pyrroles has been developed. The method offers several...
A gold-catalyzed cascade hydroamination/cyclization reaction of α-amino ketones with alkynes to form substituted pyrroles has been developed. The method offers several advantages such as high regioselectivity with the tested cases, wide functional group tolerance, and easily accessible starting materials. The synthetic utility of the obtained pyrrole products was demonstrated by their efficient transformations to 2-vinylated pyrroles via gold-catalyzed intermolecular hydroarylation.
Topics: Amination; Catalysis; Cyclization; Gold; Molecular Structure; Pyrroles
PubMed: 26030605
DOI: 10.1021/acs.orglett.5b01281 -
Chemistry (Weinheim An Der Bergstrasse,... Feb 2012Calixpyrrole-based oligomeric compounds were synthesized by "click chemistry" from the corresponding alkyne- and azide-functionalized calix[4]pyrroles. Calix[4]pyrrole...
Calixpyrrole-based oligomeric compounds were synthesized by "click chemistry" from the corresponding alkyne- and azide-functionalized calix[4]pyrroles. Calix[4]pyrrole 3, possessing an alkyne functional group, was prepared through a mixed condensation of pyrrole with acetone and but-3-ynyl 4-oxopentanoate. Another alkyne-group-containing calix[4]pyrrole 5 was obtained by treatment of 4'-hydroxyphenyl-functionalized calixpyrrole 4 with propargyl bromide. Tetrakis(azidopentyl)-functionalized calix[4]pyrrole 7 was synthesized by reacting NaN(3) with tetrabromopentyltetraethylcalix[4]pyrrole 6, which was prepared through a condensation reaction of pyrrole and 7-bromohept-2-one. Oligomeric calixpyrrole compounds were found to be capable of extracting tetrabutylammonium chloride and fluoride salts from aqueous media. Extraction abilities of the oligomeric compounds were monitored by NMR and UV/Vis spectroscopy and thermogravimetric analysis.
Topics: Calixarenes; Hydrocarbons, Halogenated; Models, Molecular; Molecular Structure; Pyrroles; Quaternary Ammonium Compounds; Salts; Water
PubMed: 22237811
DOI: 10.1002/chem.201101605