SYNTHESIS OF PYRROLE AND SUBSTITUTED PYRROLES

0 downloads 0 Views 4MB Size Report
Dec 20, 2017 - benzene chemistry, are not applicable to pyrroles. On the other hand ..... 31, 1834, 65-78. 6. A.L. Harreus, Pyrrole, Ullmann's Encyclopedia of.
Journal of Chemical Technology and Metallurgy, 53, 3,Maya 2018,Georgieva 451-464 Diana Tzankova, Stanislava Vladimirova, Lily Peikova,

SYNTHESIS OF PYRROLE AND SUBSTITUTED PYRROLES (REVIEW) Diana Tzankova1, Stanislava Vladimirova2, Lily Peikova1, Maya Georgieva1

Department of Pharmaceutical Chemistry, Faculty of Farmacy Medical University, 2 Dunav str., 1000 Sofia, Bulgaria 2 Department of Organic Synthesis and Fuels University of Chemical Technology and Metallurgy 8 Kl. Ohridski, 1756 Sofia, Bulgaria E-mail: [email protected]

1

Received 14 September 2017 Accepted 20 December 2017

ABSTRACT Pyrrole is widely known as a biologically active scaffold which possesses a diverse nature of activities. The combination of different pharmacophores in a pyrrole ring system has led to the formation of more active compounds. Pyrrole containing analogs are considered as a potential source of biologically active compounds that contains a significant set of advantageous properties and can be found in many natural products. The present review highlights the synthetic methods of representatives of nitrogen heterocycles such as pyrrole, substituted pyrroles and other related compounds. The aim of this review is to indicate and summarise the different methods for the synthesis of nitrogen containing heterocycles from the group of pyrrole and pyrrole related structures. Keywords: pyrrole, synthesis, pharmacological activity.

INTRODUCTION Pyrrole is a five membered heterocyclic compound, corresponding to the C4H4NH general formula [1]. It is a colorless volatile liquid, unstable in the presence of air, where it easily darkens. Thus a preliminary distillation before use is necessary [2]. Pyrrole is included in the group of aromatic compounds, and its hydrogenated is difficult. The DielsAlder reactions or usual olefin reactions are not characteristic for this ring. Due to the fact, that it can easy polymerize, most of the electrophilic reaction, used in benzene chemistry, are not applicable to pyrroles. On the other hand, the substituted pyrrole derivatives have been included in various transformations [3].

REACTION OF PYRROLE WITH ELECTROPHILES In general pyrroles most commonly react with electrophiles at α-position, due to the highest stability of the obtained intermediate protonation (Scheme 1). From the group of electrophilic addition, pyrroles are easily nitrated, halogenated and sulfonated, where normally polyhalogenated derivatives are obtained, but monohalogenation may also occur (Scheme 2) [6]. When the pyrrole nitrogen is silated, a halogenation on 3rd position is also possible, thus this is considered as a useful procedure for functionalization of the less active 3rd position [4]. Origin of pyrrole In 1834 F.F. Runge has detected pyrrole for the first time as a constituent of coal tar [5]. Later in 1857 it has

Scheme 1. Mehanism of the reaction of pyrrole with electrophiles.

451

Journal of Chemical Technology and Metallurgy, 53, 3, 2018

Scheme 2. Electrophilic addition of pyrroles.

Fig. 1. Heme b.

been isolated for the first time from bone pyrolysate. Its name comes from the Greekpyrrhos - based on the reaction used for its detection [6]. Pyrrole itself is not naturally occurring, but many of its derivatives are found in a variety of cofactors and natural products. Pyrroles are components of more complex macrocycles, including vitamin B12, bile pigments like bilirubin and biliverdin, and the porphyrins of heme, chlorophyll, chlorins, bacteriochlorins, and porphyrinogens [7, 8]. Pyrrole is a constituent of tobacco smoke and not as an ingredient [9].

ceuticals, medicines, agrochemicals, dyes, photographic chemicals, perfumes and other organic compounds. For example, chlorophyll, heme are derivatives which are made by four pyrrole ring formation of porphyrin ring system (Fig. 1). In addition they are used as catalysts for polymerization process, corrosion inhibitors, preservatives, solvents for resins and terpenes, standard in a chromatographic analysis and they are also used in organic synthesis in the pharmaceutical industry. It is an important constituent in the structure of a number of pharmaceutical products and new active agents with variety of pharmacological effects like: atorvastatine - antihyperlipidemic, aloracetam for treatment of Alczheimer’ disease, elopiprazole - antipsychotic, lorpiprazole - anxiolytic, tolmetin - anti-inflammatory activity (Fig. 2) [10].

Pharmacological activity of pyrrole and its derivatives Pyrrole and its derivatives play an important role in pharmaceutical and natural chemistry. Commonly they are widely used as an intermediate in the synthesis of pharma-

Fig. 2. Structure of drugs, containing pyrrole cycle.

452

Diana Tzankova, Stanislava Vladimirova, Lily Peikova, Maya Georgieva

Scheme 3. Industrial production of pyrrole.

Scheme 4. Preparation of pyrrole by catalytic dehydrogenation of pyrrolidine.

Scheme 5. Reaction of Paal-Knorr. CLASSICAL APPROACHES FOR PYRROLE SYNTHESIS Industrial preparation In industry pyrrole is produced by treatment of furan with ammonia in the presence of solid acid catalysts, like SiO2 and Al2O3 (Scheme 3) [6]. Pyrrole can also be obtained by catalytic dehydrogenation of pyrrolidine (Scheme 4). Paal-Knorr pyrrole synthesis The most prominent and applied method for synthe-

sis of pyrroles, furans and thiophenes, and their derivatives is the well known Paal-Knorr synthesis, based on a reaction of a 1,4-dicarbonyl compound with ammonia or a primary amine to form pyrrole and substituted pyrrole, respectively (Scheme 5) [11, 12]. Mechanism of Paal-Knorr pyrrole synthesis In 1991 V. Amarnath et al. [13] suggest the mechanism of Paal-Knorr reaction based on the attack of the amine to the protonated carbonyl, forming hemiaminal. Further the amine attacks the other carbonyl and forms 2,5-dihydroxytetrahydropyrrole derivative, which is further dehydrated to form the corresponding substituted pyrrole [14]. The proposed mechanism is presented on Scheme 6. The reaction is typically run under protic or Lewis acidic conditions, with a primary amine. The usage of ammonium hydroxide or ammonium acetate (as reported by Paal) gives the N-unsubstituted pyrrole [14]. SYNTHESIS OF 1,4-DIKETONES A number of methods used for synthesis of the necessary for cyclisation 1,4-diketones has been reported: One-pot method for synthesis of γ-diketones or γ-keto esters by conjugated addition of primary nitroalkans to α,β-unsaturated ketones or esters (Scheme 7) [15]. Pd-catalyzed addition [16] and cross-coupling [17] for obtaining a 1,4-diketones in good yield, as presented on Scheme 8 and Scheme 9, respectively:

Scheme 6. Mechanism of Paal-Knorr reaction.

Scheme 7. Obtaining 1,4-diketones by one-pot synthesis.

453

Journal of Chemical Technology and Metallurgy, 53, 3, 2018

Scheme 8. Obtaining 1,4-diketones by Pd-catalyzed addition.

Scheme 9. Obtaining 1,4-diketones by cross-coupling.

Scheme 10. Obtaining 1,4-diketones by Michael addition type reaction.

Scheme 11. Obtaining 1,4-diketones by α-photoalkylation of β-ketocarbonyls. The last method enables convenient preparion of functionalized 1,4-diketones and allows obtaining a stereoselective products [17]. Various 1,4-diketones have been synthesized in moderate to good yields through a Michael addition type reaction between aroyl chlorides and chalcones in the presence of samarium metal in N,N-dimethylformamide as solvent (Scheme 10) [18]. The merger of photoredox catalysis and primary amine catalysis enables a direct construction of allcarbon quaternary stereocenters via α-photoalkylation of β-ketocarbonyls with high efficacy and enantioselectivities (Scheme 11) [19].

454

MODIFIED APPROACHES FOR PAAL-KNORR PYRROLE SYNTHESIS Modifications in Paal-Knorr pyrrole synthesis The classical Paal-Knorr approach has been currently modified and optimized by a number of changes in the initial reagents and/or reaction conditions as presented on Scheme 12. A high increase of yields and an improvement of reaction rates have been accomplished by inclusion of bismute nitrate (A) [20], organic-inorganic hybrid (B) [21], silica-supported bismuth(III) chloride (BiCl3/ SiO2) (G) [22] and metal triflates as a possibility to run the reaction in a solvent free media (E) [23]. In addition

Diana Tzankova, Stanislava Vladimirova, Lily Peikova, Maya Georgieva

Scheme 12. Modifications in Paal-Knorr pyrrole synthesis.

Scheme 13. Synthesis of N-substituted pyrroles from 1,4-diketones with primary amines catalyzed by MgI2 etherate.

Scheme 14. Synthesis of pyrrole analogues by cyclocondensation of 1,4-dicarbonyl compounds with magnesium nitride. one-pot ecofriendly catalyst has been also suggested by Rahmatpour et al. (F) [24]. Currently the green chemistry is highly recommended for synthesis of new and available products. In the last years a number of modifications in PaalKnorr pyrrole synthesis have been additionally performed and reported. Wang et al. have reported synthesis of substituted pyrroles using ionic liquids as solvent. The reaction is characterized with an avoidance of using toxic catalysts and simplicity in the isolation procedure (D) [25] as well as an introduction of water as a reaction media as reported by Dilek et al. (C) [26]. Handy and associates report a method consisting in application of inexpensive, non-toxic and recyclable deep

eutectic solvents (the combination of either urea or glycerol with choline chloride) as effective solvents/catalysts for Paal-Knorr reactions to form pyrroles of furans. The reaction conditions are quite mild and do not require additional Bronsted or Lewis acid catalyst (H) [27]. Zhang et al. have described the synthesis of Nsubstituted pyrroles in good to excellent yields from various substituted 1,4-diketones with primary amines catalyzed by MgI2 etherate (Scheme 13) [28]. Veitch et al. has developed method for synthesis of pyrrole analogues by cyclocondensation of 1,4-dicarbonyl compounds with magnesium nitride as a source of ammonia (Scheme 14) [29]. Phan et al. have synthesized pyrrole analogues from benzyl amine with 2,5-hexan-

455

Journal of Chemical Technology and Metallurgy, 53, 3, 2018

Scheme 15. Synthesis of pyrrole analogues from benzyl amine with 2,5-hexanedione.

Scheme 16. Synthesis of N-substituted pyrroles under mild reaction conditions. edione using efficient heterogeneous catalyst - a highly porous metal-organic framework (IRMOF-3) as shown below (Scheme 15) [30]: On the other hand, currently number of different methods has also been developed for synthesis of pyrrole and its derivatives. Other methods for pyrrole synthesis An operationally simple and economical condensation of 2,5-dimethoxytetrahydrofuran with various primary aromatic amides in the presence of one equivalent of

thionyl chloride [31] or amines and sulfonamides in water in the presence of catalytic amount of iron(III) chloride [32] led to formation of N-substituted pyrroles under mild reaction conditions in good yields (Scheme 16). An interesting approach for polysubstituted pyrrole synthesis is through reaction of 1-sulfonyl-1,2,3triazoles with allenes in the presence of a nickel(0) catalyst as described in Miura et al. [33] (Scheme 17A). This compound has been considered also from other authors as an initial component for synthesis of mono-, di- and tri-substituted pyrroles by rhodium (II)-catalyzed

Scheme 17A. Synthesis of polysubstituted pyrrole through reaction of 1-sulfonyl-1,2,3-triazoles with allenes.

Scheme 17B. Synthesis of mono-, di- and tri-substituted pyrroles by rhodium (II)-catalyzed cycloaddition with isoxazoles.

456

Diana Tzankova, Stanislava Vladimirova, Lily Peikova, Maya Georgieva

Scheme 17C. Synthesis of mono-, di- and tri-substituted pyrroles by transannulation with vinyl ether.

Scheme 17D. Synthesis of mono-, di- and tri-substituted pyrroles by transannulation with alkenyl alkyl ethers.

Scheme 18. Synthesis of pyrroles by Cu-catalysis reaction of 1,4-dihalo-1,3 dienes.

Scheme 19. Synthesis of pyrroles by copper catalyzed double alkenylation of amides.

Scheme 20. Synthesis of substituted NH pyrroles by vinyl azides annulation with esters and/or aldehydes. cycloaddition with isoxazoles (Scheme 17B) [34] or transannulation with vinyl ether (Scheme 17C) [35] or with alkenyl alkyl ethers (Scheme 17D) [36]. A highly efficient reaction of 1,4-dihalo-1,3dienes

has been described for formation of pyrroles and heteroaryl pyrroles under Cu-catalysis (Scheme 18) [37] and copper catalyzed double alkenylation of amides (Scheme 19) [38].

457

Journal of Chemical Technology and Metallurgy, 53, 3, 2018

Scheme 21A. Synthesis of substituted NH pyrroles under mild and simple conditions.

Scheme 21B. Synthesis of substituted NH pyrroles under mild and simple conditions.

Scheme 21C. Synthesis of substituted NH pyrroles under mild and simple conditions. New approaches for obtaining substituted NH pyrroles have been developed based on vinyl azides annulation with esters and/or aldehydes, as presented on Scheme 20, ensuring good yields obtained under mild, neutral and very simple conditions [39 - 43] (Scheme 21A, Scheme 21B and Scheme 21C).

Various polysubstituted pyrroles are easily accessible from acetylenes and alkynes interacting with the corresponding N-containing substances in one-step (Scheme 22A) [44] and in highly regioselective manner (Scheme 22B) [45], (Scheme 23) [46].

Scheme 22A. One-step synthesis of polysubstituted pyrroles.

Scheme 22B. Synthesis of polysubstituted pyrroles by regioselective manner.

Scheme 23. Synthesis of polysubstituted pyrroles by regioselective manner.

458

Diana Tzankova, Stanislava Vladimirova, Lily Peikova, Maya Georgieva

Scheme 24A. Synthesis of pyrroles by gold-catalyzed reactions of 2H-azirines with ynamides.

Scheme 24B. Synthesis of pyrroles by cyclization of α-amino ketones with alkynes.

Scheme 25. Synthesis of pyrrole derivatives by condensation of propargyl amines with ethyl vinyl ether under microwave irradiation.

Scheme 26. Microwave-promoted formation of 2-acylpyrroles by iminyl radical cyclizations. Recently other authors have obtained substituted pyrroles in good yields, using gold-catalyzed reactions of 2H-azirines with ynamides [47], and cyclization of α-amino ketones with alkynes [48], (Scheme 24A and Scheme 24B). Other preparation of pyrrole derivatives has been reported, consisting of condensation of propargyl amines with ethyl vinyl ether under microwave irradiation in good yields (Scheme 25) [49]. Another microwave-promoted formation of 2-acylpyrroles in good yields is iminyl radical cyclizations, terminated by trapping with TEMPO, affording functionalized adducts without using toxic and hazardous reagents and using alkynes as radical acceptors (Scheme 26) [50].

Currently Zheng et al. and Gao et al. have synthesized polysubstituted pyrroles by formation of C-C and C-N bonds from N-homo allylicamines with arylboronic acids and phenyl acetaldehydes with primary amines as shown in Scheme 27A and Scheme 27B [51, 52]. Another method is synthesis of pyrrole derivatives by an one-pot hetero-Diels-Alder/ring contraction cascade affords N-arylpyrroles from 1,3-dienylboronic esters with nitrosoarenes in excellent yields (Scheme 28) [53]. Recently Bayat et al. have described new fused heterocyclic derivatives of pyrrole containing acetonitrile or cyanoacetonitrile moiety at 3-position by an one-pot multicomponent reaction in good yields, Scheme 29 [54].

459

Journal of Chemical Technology and Metallurgy, 53, 3, 2018

Scheme 27A. Synthesis of polysubstituted pyrroles from N-homo allylicamines with arylboronic acids.

Scheme 27B. Synthesis of polysubstituted pyrroles from phenyl acetaldehydes with primary amines.

Scheme 28. Synthesis of N-arylpyrroles from 1,3-dienylboronic esters with nitrosoarenes.

Scheme 29. Synthesis of heterocyclic derivatives of pyrrole by one-pot multicomponent reaction.

Scheme 30. Synthesis of 2-substituted pyrroles using Pd, Ru and Fe catalyst. Bunrit et al. have described a new method for synthesis of 2-substituted pyrroles in overall good yields with only water and ethene as side-products using Pd, Ru and Fe catalyst, (Scheme 30), [55].

460

SYNTHESIS OF SUBSTITUTED PYRROLES Substituted pyrroles in excellent yields have formulated by highly regioselective N-substitution of pyrrole with alkyl halides, sulfonyl chlorides, and benzoyl

Diana Tzankova, Stanislava Vladimirova, Lily Peikova, Maya Georgieva

Scheme 31. Synthesis of N-substituted pyrroles.

Scheme 32. Synthesis of 1-vinylpyrroles.

Scheme 33. Synthesis of 2-alkyl-1H-indoles and substituted 5-alkyl-1H-pyrroles.

Scheme 34. Synthesis of alkyl N-methylpyrrolyl ketones or aryl N-methylpyrrolyl ketones. chloridein ionic liquids [Bmim][PF6] or [Bmim][BF4] as shown in Scheme 31 [56]. 1-Vinylpyrroles have synthesized by the N,Ndimethyl¬formamide/oxalyl chloride reagent system to give the corresponding 1-vinylpyrrole-2-carbaldehydes in good yields in short reaction times (Scheme 32) [57]. 2-alkyl-1H-indoles and 2-substituted or 2,3-disubstituted 5-alkyl-1H-pyrroles have been synthesized in good yields by the 1H-indoles and electron-deficient 1H-pyrroles, palladium/norbornene-cocatalyzed regioselective alkylation with primary alkyl bromides at the C-H bond adjacent to the NH group (Scheme 33) [58]. The transient acid iodide intermediates undergo nucleophilic attack from a variety of relatively weak nucleophiles - including Friedel-Crafts acylation of Nmethylpyrroles N-acylation of sulfonamides, and acylation reactions of hindered phenol derivatives (Scheme 34) [59].

CONCLUSIONS The current review presents the synthetic methods for obtaining pyrrole, substituted pyrroles and other related compounds in high to excellent yields under mild, neutral and very simple reaction conditions and/or presence of different catalysts like microwave-promoted irradiation, introduction of a number of metals and metal complexes as a reaction catalysist like Pd, Ru, Li, Fe, etc. A green chemistry reaction conditions and one-pot synthetic approaches are also discussed, based on application of media-free reactions and usage of enviromentally friendly recyclable catalysts. REFERENCES 1. M.G. Loudon, Chemistry of Naphthalene and the Aromatic Heterocycles.Organic Chemistry, 4th ed., New York: Oxford University Press, 2002, 11351136, ISBN0-19-511999-1.

461

Journal of Chemical Technology and Metallurgy, 53, 3, 2018

2. W.L.F. Armarego, C.L.L. Chai, Purification of Laboratory Chemicals, 5th ed., Elsevier, 2003, 608. 3. W. Lubell, D. Saint-Cyr, J. Dufour-Gallant, R. Hopewell, N. Boutard, T. Kassem, A. Dörr, R. Zelli, 1H-Pyrroles, Science of Synthesis, 1, 2013, 157-388. 4. A.P. Kozikowaki, X.M. Cheng, A synthesis of 3-Substituted Pyrroles through the Halogen-Mateal Exchange Reaction of 3-Bromo-1-(triisopropylsilyl) pyrrole, J. Org. Chem., 49, 1984, 3239-3240. 5. F.F. Runge, Über einige Produkte der Steinkohlendestillation [On some products of coal distillation], Annalen der Physik und Chemie, 31, 1834, 65-78. 6. A.L. Harreus, Pyrrole, Ullmann’s Encyclopedia of Industrial Chemistry, 30, 2012, 615-618. 7. J. Jusélius, D. Sundholm, The aromatic pathways of porphins, chlorins and bacteriochlorins, Phys. Chem. Chem. Phys., 2, 10, 2000, 2145-2151. 8. M. Cox, A.L. Lehninger, D.R. Nelson, Lehninger Principles of Biochemistry. New York: Worth Publishers, 2000, ISBN 1-57259-153-6. 9. J. Fowles, M. Bates, D. Noiton, The Chemical Constituents in Cigarettes and Cigarette Smoke: Priorities for Harm Reduction: a Report to the New Zealand Ministry of Health, 20, 2000, 49-65. 10. V. Bhardwaj, D. Gumber, V. Abbot, S. Dhimanand, P. Sharmaa, Pyrrole: a resourceful small molecule in keymedicinal hetero-aromatics, RSC Adv., 5, 2015, 15233. 11. C. Paal, Über die Derivate des Acetophenonacetessigesters und des Acetonylacetessigesters, Berichte der deutschen chemischen Gesellschaft, 17, 1884, 2756-2767. 12. L. Knorr, Synthese von Furfuranderivaten aus dem Diacetbernsteinsäureester [Synthesis of furan derivatives from the [diethyl] ester of 2,3-diacetylsuccinic acid], Berichte der deutschen chemischen Gesellschaft, 17, 1884, 2863-2870. 13. V. Amarnath, D.C. Anthony, K. Amarnath, W.M. Valentine, L.A. Wetterau, D.G. Graham, Intermediates in the Paal-Knorr synthesis of pyrroles, The Journal of Organic Chemistry, 56, 1991, 6924. 14. A. Wollrab, Organische Chemie, Springer-Verlag, 1999, 850, ISBN 3-540-43998-6. 15. R. Ballini, L. Barboni, G. Bosica, D. Fiorini, OnePot Synthesis of γ-Diketones, γ-Keto Esters, and Conjugated Cyclopentenones from Nitroalkanes, Synthesis, 2002, 2725-2728.

462

16. D.W. Custar, H. Le, J.P. Morken, Pd-Catalyzed Carbonylative Conjugate Addition of Dialkylzinc Reagents to Unsaturated Carbonyls, Org. Lett., 12, 2010, 3760-3763. 17. B.B. Parida, P.P. Das, M. Niocel, J.K. Cha, C-Acylation of Cyclopropanols: Preparation of Functionalized 1,4-Diketones, Org. Lett., 15, 2013, 1752-1783. 18. Y. Liu, Y. Li, Y. Qi, J. Wan, Samarium-Promoted Michael Addition between Aroyl Chlorides and Chalcones, Synthesis, 2010, 4188-4192. 19. Y. Z h u , L . Z h a n g , S . L u o , A s y m m e t r i c α-Photoalkylation of β-Ketocarbonyls by Primary Amine Catalysis: Facile Access to Acyclic AllCarbon Quaternary Stereocenters, J. Am. Chem. Soc., 136, 2014, 14642-14645. 20. B.K. Banik, I. Banik, M. Renteria, S.K. Dasgupta, A straightforward highly efficient Paal–Knorr synthesis of pyrroles, Tetrahedron letters, 46, 15, 2005, 2643-2645. 21. L. Gao, L. Bing, Z. Zhang, H. Kecheng, H. Xiaoyun, K. Deng, Efficient synthesis of N-substituted pyrroles catalyzed by a novel an organiceinorganic hybrid solid acid catalyst, Journal of Organometallic Chemistry, 735, 2013, 26-31. 22. K. Aghapoor, L. Ebadi-Nia, F. Mohsenzadeh, M.M. Morad, Y. Balavar, H.R. Darabi, Silica-supported bismuth(III) chloride as a new recyclable heterogeneous catalyst for the Paal–Knorr pyrrole synthesis, Journal of Organometallic Chemistry, 708-709, 2012, 25-30. 23. J. Chen, H. Wu, Z. Zheng, C. Jin, X. Zhang, W. Su, An approach to the Paal–Knorr pyrroles synthesis catalyzed by Sc(OTf)3 under solvent-free conditions, Tetrahedron Letters, 47, 2006, 5383-5387. 24. A. Rahmatpour, Polystyrene-supported GaCl3 as a highly efficient and recyclable heterogeneous Lewis acid catalyst for one-pot synthesis of N-substituted pyrroles, Journal of Organometallic Chemistry, 712, 2012, 15-19. 25. B. Wang, Y. Gu, C. Luo, T. Yang, L. Yang, J. Suo, Pyrrole synthesis in ionic liquids by Paal–Knorr condensation under mild conditions, Tetrahedron letters, 45, 2004, 3417-3419. 26. D. Akbaşlar, O. Demirkol, S. Giray, Paal-Knorr Pyrrole Synthesis in Water, Synthetic Communications: An International Journal for Rapid Communication of Synthetic Organic Chemistry, 44, 9, 2014, 1323-1332.

Diana Tzankova, Stanislava Vladimirova, Lily Peikova, Maya Georgieva

27. S. Handy, K. Lavender, Organic synthesis in deep eutectic solvents: Paal–Knorr reactions, Cheminform, 44, 47, 2013. 28. X. Zhang, G. Weng, Y. Zhang, P. Li, Unique chemoselective Paal-Knorr reaction catalyzed by MgI2 etherate under solvent-free conditions, Tetrahedron, 71, 2015, 2595-2602. 29. G.E. Veitch, K.L. Bridgwood, K. Rands-Trevor, S.V. Ley, Magnesium Nitride as a Convenient Source of Ammonia: Preparation of Pyrroles, Synlett, 2008, 2597-2600. 30. N.T.S. Phan, T.T. Nguyen, Q.H. Luu, L.T.L. Nguyen, Paal-Knorr reaction catalyzed by metal–organic framework IRMOF-3 as an efficient and reusable heterogeneous catalyst, Journal of Molecular Catalysis A: Chemical, 363-364, 2012, 178-185. 31. A.R. Ekkati, D.K. Bates, A Convenient Synthesis of N-Acylpyrroles from Primary Aromatic Amides, Synthesis, 2003, 1959-1961. 32. N. Azizi, A. Khajeh-Amiri, H. Ghafuri, M. Bolourtchian, M.R. Saidi, Iron-Catalyzed Inexpensive and Practical Synthesis of N-Substituted Pyrroles in Water, Synlett, 2009, 2245-2248. 33. T. Miura, K. Hiraga, T. Biyajima, T. Nakamuro, M. Murakami, Regiocontrolled Synthesis of Polysubstituted Pyrroles Starting from Terminal Alkynes, Sulfonyl Azides, and Allenes, Org. Lett., 15, 2013, 3298-3301. 34. X. Lei, L. Li, Y.-P. He, Y. Tang, Rhodium(II)Catalyzed Formal [3 + 2] Cycloaddition of NSulfonyl-1,2,3-triazoles with Isoxazoles: Entry to Polysubstituted 3-Aminopyrroles, Org. Lett., 17, 2015, 5224-5227. 35. S. Rajasekar, P. Anbarasan, Rhodium-Catalyzed Transannulation of 1,2,3-Triazoles to Polysubstituted Pyrroles, J. Org. Chem., 79, 17, 2014, 84288434. 36. C.E. Kim, S. Park, D. Eom, B. Seo, P.H. Lee, Synthesis of Pyrroles from Terminal Alkynes, NSulfonyl Azides, and Alkenyl Alkyl Ethers through 1-Sulfonyl-1,2,3-triazoles, Org. Lett., 16, 2014, 1900-1903. 37. R. Martín, C.H. Larsen, A. Cuenca, S.L. Buchwald, Cu-Catalyzed Tandem C-N Bond Formation for the Synthesis of Pyrroles and Heteroarylpyrroles, Org. Lett., 9, 2007, 3379-3382. 38. X. Yuan, X. Xu, X. Zhou, J. Yuan, L. Mai, Y. Li,

Copper-Catalyzed Double N-Alkenylation of Amides: An Efficient Synthesis of Di- or Trisubstituted N-Acylpyrroles, J. Org. Chem., 72, 2007, 1510-1513. 39. E.P.J. Ng, Y.F. Wang, S. Chiba, Manganese(III)Catalyzed Formal [3+2] Annulation of Vinyl Azides and β-Keto Acids for Synthesis of Pyrroles., Synlett, 2011, 783-786. 40. F. Chen, T. Shen, Y. Cui, N. Jiao, 2,4- vs 3,4-Disubsituted Pyrrole Synthesis Switched by Copper and Nickel Catalysts, Org. Lett., 14, 2012, 4926-4929. 41. D.J. Gorin, N.R. Davis, F.D. Toste, Gold(I)-Catalyzed Intramolecular Acetylenic Schmidt Reaction, J. Am. Chem. Soc., 127, 2005, 11260-11261. 42. Y. Wu, L. Zhu, Y. Yu, X. Luo, X. Huang, Polysubstituted 2-Aminopyrrole Synthesis via Gold-Catalyzed Intermolecular Nitrene Transfer from Vinyl Azide to Ynamide: Reaction Scope and Mechanistic Insights, J. Org. Chem., 80, 2015, 11407-11416. 43. H. Dong, M. Shen, J.E. Redford, B.J. Stokes, A.L. Pumphrey, T.G. Driver, Transition Metal-Catalyzed Synthesis of Pyrroles from Dienyl Azides, Org. Lett., 9, 2007, 5191-5194. 44. O.V. Larionov, A. de Meijere, Versatile Direct Synthesis of Oligosubstituted Pyrroles by Cycloaddition of α-Metalated Isocyanides to Acetylenes, Angew. Chem. Int. Ed., 44, 2005, 5664-5667. 45. M.L. Crawley, I. Goljer, D.J. Jenkins, J.F. Mehlmann, L. Nogle, R. Dooley, P.E. Mahaney, Regioselective Synthesis of Substituted Pyrroles: Efficient Palladium-Catalyzed Cyclization of Internal Alkynes and 2-Amino-3-iodoacrylate Derivatives, Org. Lett., 8, 2006, 5837-5840. 46. D. Suzuki, Y. Nobe, R. Tanaka, Y. Takayama, F. Sato, H. Urabe, Facile Preparation of Various Heteroaromatic Compounds via Azatitanacyclopentadiene Intermediates, J. Am. Chem. Soc., 127, 2005, 74747479. 47. L. Zhu, Y. Yu, Z. Mao, X. Huang, Gold-Catalyzed Intermolecular Nitrene Transfer from 2H-Azirines to Ynamides: A Direct Approach to Polysubstituted Pyrroles, Org. Lett., 17, 2015, 30-33. 48. X. Li, M. Chen, X. Xie, N. Sun, S. Li, Y. Liu, Synthesis of Multiple-Substituted Pyrroles via Gold(I)Catalyzed Hydroamination/Cyclization Cascade., Org. Lett., 17, 2015, 2984-2987. 49. H. Chachignon, N. Scalacci, E. Petricci, D. Castag-

463

Journal of Chemical Technology and Metallurgy, 53, 3, 2018

nolo, Synthesis of 1,2,3-Substituted Pyrroles from Propargylamines via a One-Pot Tandem Enyne Cross Metathesis-Cyclization Reaction, J. Org. Chem., 80, 2015, 5287-5295. 50. Y. Cai, A. Jalan, A. R. Kubosumi, S. L. Castle, Microwave-Promoted Tin-Free Iminyl Radical Cyclization with TEMPO Trapping: A Practical Synthesis of 2-Acylpyrroles, Org. Lett., 17, 2015, 488-491. 51. J. Zheng, L. Huang, C. Huang, W. Wu, H. Jiang,Copper-Catalyzed Synthesis of Substituted Quinolines via C-N Coupling/Condensation from ortho-Acylanilines and Alkenyl Iodides, J. Org. Chem., 80, 2015, 1235-1242. 52. Y. Gao, C. Hu, J. P. Wan, C. Wen, Metal-free cascade reactions of aldehydes and primary amines for the synthesis of 1,3,4-trisubstituted pyrroles, Tetrahedron Letters, 57, 2016, 4854-4857. 53. L. Eberlin, B. Carboni, A. Whiting, Regioisomeric and Substituent Effects upon the Outcome of the Reaction of 1-Borodienes with Nitrosoarene Compounds, J. Org. Chem., 80, 13, 2015, 6574-6583. 54. M. Bayat, S. Nasri, B. Notash, Synthesis of new

464

3-cyanoacetamide pyrrole and 3-acetonitrile pyrrole derivatives, Tetrahedron, 73, 11, 2017, 1522-1527. 55. A. Bunrit, S. Sawadjoon, S. Tšupova, P.J.R. Sjöberg, J.S.M. Samec, A General Route to β-Substituted Pyrroles by Transition-Metal Catalysis, J. Org. Chem., 81, 2016, 1450-1460. 56. Z.G. Lea, Z.C. Chen, Y. Hu, Q.G. Zheng, Organic Reactions in Ionic Liquids: A Simple and Highly Regioselective N-Substitution of Pyrrole, Synthesis, 2004, 1951. 57. A.I. Mikhaleva, A.V. Ivanoc, E.V. Skital’tseva, I.A. Ushakov, A.M. Vasil’tsov, B.A. Trofimov, An Efficient Route to 1-Vinylpyrrole-2-carbaldehydes, Synthesis, 2009, 587-590. 58. L. Jiao, T. Bach, Regioselective Direct C-H Alkylation of NH Indoles and Pyrroles by a Palladium/ Norbornene-Cocatalyzed Process, Synthesis, 46, 2014, 35-41. 59. R.J. Wakeham, J.E. Taylor, S.D. Bull, J.A. Morris, J.M.J. Williams, Iodide as an Activating Agent for Acid Chlorides in Acylation Reactions, Org. Lett., 15, 2013, 702-705.