Trisubstituted Pyrroles Research Articles

Au(I)-Catalyzed Rearrangement Reaction of Propargylic Aziridine: Synthesis of Trisubstituted and Cycloalkene-Fused Pyrroles

A rearrangement reaction of propargylic aziridine, catalyzed by PPh(3)AuCl/AgOTf, forming trisubstituted and cycloalkene-fused pyrroles is described which involves an unusual tandem cyclization/ring-opening/Wagner-Meerwein process. The unique structures of the products demonstrated its potential applications for synthesizing structurally diverse alkaloids.

Synthesis of Polysubstituted Pyrroles

Cross coupling metathesis reactions from two ethylenic compounds 4 and 5 easily led to Michael acceptors 6ab and 7a-b. Reaction of these compounds, or of enone 5, with p-toluenesulfonylmethyl isocyanide (TosMIC) provided the disubstituted pyrroles 9a-c and 10a-b. The analogous reaction of compounds 6a-b and 5, but in presence of Ph3SnCl, provided the trisubstituted pyrroles 11a-c. All of these compounds 9-11 were thus obtained in two steps only. Keywords: Lavendamycin, pyrroles, TosMIC, Michael acceptors, cross metathesis

Synthesis of Trisubstituted Pyrroles from Rhodium‐Catalyzed Alkyne Head‐to‐Tail Dimerization and Subsequent Gold‐ Catalyzed Cyclization

Abstractmagnified imageDimerization of N‐protected propargylic amines in a rather rare head‐to‐tail mode has been achieved under mild conditions with high selectivity using rhodium catalysts. The N‐protecting group could be a sulfonyl, carbamate, or carbonyl functionality and (cyclooctadiene)rhodium chloride dimer/1,1′‐bis(diphenylphosphino)ferrocene {[Rh(COD)Cl]2/dppf} as well as tris(triphenylphosphine)rhodium chloride [Rh(PPh3)3Cl] proved to be active catalysts. In addition, these functionalized gem‐enynes subsequently undergo selective gold(III)‐catalyzed intramolecular hydroamination to give trisubstituted pyrroles under mild conditions.

Catalytic Multicomponent Reactions for the Synthesis of N‐Aryl Trisubstituted Pyrroles.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Rh-Catalyzed Synthesis of N-Aryl Trisubstituted Pyrroles

Rh-Catalyzed Synthesis of <i>N</i>-Aryl Trisubstituted Pyrroles

Catalytic Multicomponent Reactions for the Synthesis of N-Aryl Trisubstituted Pyrroles

Dirhodium(II) salts efficiently catalyze the three-component assembly reaction of an imine, diazoacetonitrile (DAN), and an activated alkynyl coupling partner to form substituted 1,2-diarylpyrroles in moderate to good yields. The transition-metal-catalyzed decomposition of the diazo compound in the presence of the imine presumably generates a transient azomethine ylide that undergoes cycloaddition with dipolarophiles in a highly convergent manner.

Zinc tetrafluoroborate-catalysed synthesis of highly substituted pyrroles by a solvent-free reaction

A simple and highly efficient synthesis of penta- and tri-substituted pyrroles has been developed using the Paal–Knorr reaction catalysed by aqueous zinc tetrafluoroborate at room temperature under solvent-free conditions.

3‐Aryl‐2‐chloropropanals in Hantzsch Synthesis of Pyrroles.

AbstractFor Abstract see ChemInform Abstract in Full Text.

3-Aryl-2-chloropropanals in Hantzsch Synthesis of Pyrroles

Pyrroles have been obtained by the Hantzsch method, by reaction of α-halocarbonyl and 1,3-dicarbonyl compounds in the presence of ammonia [1-3]. However, the range of α-halo-substituted aldehydes used in this synthesis is quite limited [1-4]. In this paper, we show that in this reaction we can use 3-aryl-2-chloropropanals 1a-d, obtained by Meerwein chloroarylation of acrolein [5]. We have established that aldehydes 1a-d react under mild conditions with acetoacetic and benzoylacetic esters in the presence of ammonia to form ethyl esters of 4(R-benzyl)-2-methyl(phenyl)pyrrole-3-carboxylic acids 2a-e. Dehydrochlorination of α-chloro aldehydes 1a-d does not occur in this case. Pyrrole is formed as a result of C-alkylation of the intermediate enamine followed by cyclization. The proposed method allows us to obtain trisubstituted pyrroles containing benzyl substituents in the 4 position.

Chemoselective Reduction of a Lactam Carbonyl Group in the Presence of a gem‐Dicarboxylate by Sodium Borohydride and Iodine: A Facile Entry to N‐Aryl Trisubstituted Pyrroles.

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Chemoselective reduction of a lactam carbonyl group in the presence of a gem-dicarboxylate by sodium borohydride and iodine: a facile entry to N-aryl trisubstituted pyrroles

Several N-aryl γ-lactam gem dicarboxylates were chemoselectively reduced to cyclic amine diesters by using sodium borohydride–iodine system. The reduction in all cases was completed within 2.5 h after refluxing in THF. The cyclic amine products were isolated after aqueous (acidic) workup in good yields. Hydrolytic decarboxylation followed by dehydrogenation produced N-aryl carboethoxy pyrroles.

1,2‐Migration of the Thio Group in Allenyl Sulfides: Efficient Synthesis of 3‐Thio‐Substituted Furans and Pyrroles.

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ChemInform Abstract: Alkylation of β‐(Hydroxymethyl)pyrroles: A New Synthesis of Porphobilinogen and Other Trisubstituted Pyrroles for Photodynamic Therapy.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Alkylation of beta-(Hydroxymethyl)pyrroles: A New Synthesis of Porphobilinogen and Other Trisubstituted Pyrroles for Photodynamic Therapy.

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTAlkylation of β-(Hydroxymethyl)pyrroles: A New Synthesis of Porphobilinogen and Other Trisubstituted Pyrroles for Photodynamic TherapyChristine Y. De Leon and Bruce GanemView Author Information Department of Chemistry, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301 Cite this: J. Org. Chem. 1996, 61, 25, 8730–8731Publication Date (Web):December 13, 1996Publication History Received23 October 1996Published online13 December 1996Published inissue 1 January 1996https://doi.org/10.1021/jo961987jCopyright © 1996 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views851Altmetric-Citations17LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (167 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Alcohols,Ethyl groups,Post-translational modification,Pyrroles,Substitution reactions Get e-Alerts

New efficient and flexible synthesis of polysubstituted pyrroles

The Lewis acid mediated reaction of readily available 2-acetoxypropanal-N,N-dimethylhydrazone 1 with various open chain and cyclic silyl enol ethers 2 leads directly or via 4-oxoaldehyde-N,N-dimethylhydrazones 3 to N-(dimethylamino)-pyrroles 4. The subsequent reductive NN bond cleavage provides an efficient and flexible method for the preparation of alkyl-aryl-di- and trisubstituted pyrroles 5.

ChemInform Abstract: Reaction of a Chromium Carbene Complex with 1‐Azadienes and the Synthesis of Trisubstituted Pyrroles.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Reaction of a chromium carbene complex with 1-azadienes and the synthesis of trisubstituted pyrroles

Thermolysis of chromium carbene complexes with 1-azadienes leads to formation of trisubstituted pyrroles in good yield.

A Convenient Synthesis of Pyrrole- and N-Aminopyrrole-3-propionate Esters

Trisubstituted pyrroles having a substitution pattern found in many naturally occurring linear and macrocyclic tetrapyrroles have been prepared in a regiospecific fashion by a two step sequence involving Diels-Alder reaction of 2-oxo-3-butenoate esters (58) with 2-alkoxy-1,3-pentadiene derivatives (46), followed by ozonolysis and Paal-Knorr cyclization

2-oxo-3-butenoate esters as dienophiles and their utility in a novel synthesis of pyrroles

Trisubstituted pyrroles of type 8 have been prepared in a regiospecific fashion by a two step sequence involving Diels-Alder reaction of 2-oxo-3-butenoate esters 1 with 2-alkoxy-1,3-pentadiene derivatives 13, followed by ozonolysis and Paal-Knorr cyclization.

Transition metal‐ and acid‐induced transformations of 6‐siloxy‐substituted 5,6‐dihydro‐4H‐1,2‐oxazines: Preparation of pyrroles, nitrones, 1,4‐dicarbonyl compounds and derivatives thereof

AbstractA variety of 6‐siloxy‐substituted 5,6‐dihydro‐4H‐1,2‐oxazines (abbreviation: 1,2‐oxazines) 1, 3 could be transformed into di‐ and trisubstituted pyrroles 2, 4 by means of molybdenum hexacarbonyl. The mechanism of this deoxygenating ring contraction is discussed. With two bicyclic 1,2‐oxazines an acid‐catalyzed fragmentation affording α‐methylenecycloalkanones 7 has been observed, while other 1,2‐oxazines rearrange in methanolic acid to give nitrones 9, 10. The desilylation of 6‐siloxy‐substituted 1,2‐oxazines 1, 3 employing NEt3 · 3 HF is a very general and smooth process providing 6‐hydroxy‐1,2‐oxazines 11, 12 or their corresponding acyclic tautomers 13, 14 in high yields. For two examples of 11 deoximations by use of formalin could be achieved with moderate efficiency giving 1,4‐dicarbonyl compounds 15.