Recent Advances in the Synthesis of Pyrroles

Page: [1196 - 1229] Pages: 34

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Abstract

Pyrroles are the most prevalent heterocyclic compounds, which are present as the basic cores in many natural products, such as vitamin B12, bile pigments like bilirubin and biliverdin, the porphyrins of heme, chlorophyll, chlorins, bacteriochlorins, and porphyrinogens. The biological activities of compounds having pyrrole analogs include antimicrobial (antibacterial, antifungal), anti-cancer (anti-cytotoxic, antimitotic), anti-tumor, anti-hyperlipidemic, anti-depressant, anti-inflammatory, antihyperglycemic, antiproliferative, anti-HIV and anti-viral activities. Accordingly, significant attention has been paid to develop competent methods for the synthesis of pyrroles with improved yields in short times. This review gives an overview of different methods for the synthesis of pyrrole using easily available precursors using the following routes.

- Synthesis of monosubstituted pyrrole using 2,5-dimethoxyfuran

- Synthesis of pyrrole using dialkylacetylene dicarboxylate

-Synthesis of pyrroles using β-ketoester

-Synthesis of pyrrole using 1,2-dicarbonyl compounds

-Synthesis of pyrroles using 1,3-dicarbonyl compounds

-Synthesis of pyrroles using 1,3-dicarbonyl, amine, nitro and aldehyde group

-Synthesis of pyrroles using 1,4-dicarbonyl compound and amines

-Synthesis of pyrrole using enones

- Synthesis of pyrroles using moieties having acetylene group

Keywords: Pyrrole, dimethoxyfuran, dialkylacetylene dicarboxylate, 1, 4-dicarbonyl compound, β-ketoester, vitamin B12.

Graphical Abstract

[1]
Katritzky, A.R.; Rees, C.W.; Scriven, E.F. Comprehensive Heterocyclic Chemistry II; Elsevier Science Ltd., 1996.
[2]
Gandi, S.; Baire, B. Ag(I) catalyzed cascade approach to 2-(α-Hydroxyacyl) pyrroles. ChemistrySelect, 2017, 2, 3964-3968.
[http://dx.doi.org/10.1002/slct.201700514]
[3]
Jones, R.A. Pyrrole: The Synthesis and the Physical and Chemical Aspects of Pyrrole Ring, Wiley-Interscience: Mishawaka 1990.
[4]
Bayat, M.; Nasri, S.; Notash, B. Synthesis of new 3-cyanoacetamide pyrrole and 3-acetonitrile pyrrole derivatives. Tetrahedron, 2017, 73, 1522-1527.
[http://dx.doi.org/10.1016/j.tet.2017.02.005]
[5]
Jones, R.A.; Bean, G.P. The Chemistry of Pyrroles: Org. Chem. A Series of Monographs; Academic Press, 2013, Vol. 34, .
[6]
Jordan, P.M. The biosynthesis of 5-aminolaevulinic acid and its transformation into uroporphyrinogen III. In: New Comprehensive Biochemistry., Elsevier Science Ltd.. 1991, Vol. 19, 1-66.
[7]
Schobert, R.; Schlenk, A. Tetramic and tetronic acids: an update on new derivatives and biological aspects. Bioorg. Med. Chem., 2008, 16(8), 4203-4221.
[http://dx.doi.org/10.1016/j.bmc.2008.02.069] [PMID: 18334299]
[8]
Kibriz, I.E.; Sacmaci, M.; Sahin, E.; Yildirim, I. Preparation of novel pyrrol-2-one derivatives via an effective synthesis of new oxazole scaffold. Tetrahedron, 2017, 73, 1795-1802.
[http://dx.doi.org/10.1016/j.tet.2017.01.046]
[9]
Bivava, M.; Fioravanti, R.; Porreta, G.C.; Deidda, D.; Maullu, C.; Pomei, R. New pyrrole derivatives as antimycobacterial agents analogs of BM212. Bioorg. Med. Chem. Lett., 1999, 9, 2983-2988.
[10]
Clive, D.L.J.; Cheng, P. The marinopyrroles. Tetrahedron, 2013, 69, 5059-5066.
[http://dx.doi.org/10.1016/j.tet.2013.04.036]
[11]
Dmitriev, M.V.; Salnikova, T.V.; Silaichev, P.S.; Maslivets, A.N. One-pot, three-component synthesis of spiro[indeno[1,2-b]quinoline-10,3′-pyrroles] via the Hantzsch-type reaction of 1H-pyrrole-2,3-diones. Tetrahedron Lett., 2017, 58, 67-70.
[http://dx.doi.org/10.1016/j.tetlet.2016.11.100]
[12]
Jana, G.H.; Jain, S.; Arora, S.K.; Sinha, N. Synthesis of some diguanidino 1-methyl-2,5-diaryl-1H-pyrroles as antifungal agents. Bioorg. Med. Chem. Lett., 2005, 15(15), 3592-3595.
[http://dx.doi.org/10.1016/j.bmcl.2005.05.080] [PMID: 15978808]
[13]
Liu, J.; Du, Y.Q.; Li, C.J.; Li, L.; Chen, F.Y.; Yang, J.Z.; Chen, N.H.; Zhang, D.M. Alkaloids from the stems of Clausena lansium and their neuroprotective activity. RSC Adv., 2017, 7, 35417-35425.
[http://dx.doi.org/10.1039/C7RA06753D]
[14]
Etcheverry, S.B.; Barrio, D.A.; Cortizo, A.M.; Williams, P.A. Three new vanadyl(IV) complexes with non-steroidal anti-inflammatory drugs (Ibuprofen, Naproxen and Tolmetin). Bioactivity on osteoblast-like cells in culture. J. Inorg. Biochem., 2002, 88(1), 94-100.
[http://dx.doi.org/10.1016/S0162-0134(01)00368-3] [PMID: 11750030]
[15]
Lmbri, D.; Tauber, J.; Opatz, T. Synthetic approaches to the Lamellarins - a comprehensive review. Mar. Drugs, 2014, 12, 6142-6177.
[http://dx.doi.org/10.3390/md12126142] [PMID: 25528958]
[16]
Ham, J.Y.; Kang, H.J. A novel cytotoxic alkaloid of lamellarin class from a marine ascidian Didemnum sp. Bull. Korean Chem. Soc., 2002, 23, 163-166.
[http://dx.doi.org/10.5012/bkcs.2002.23.1.163]
[17]
Roth, B.D. The discovery and development of atorvastatin, a potent novel hypolipidemic agent. Prog. Med. Chem., 2002, 40, 1-22.
[http://dx.doi.org/10.1016/S0079-6468(08)70080-8] [PMID: 12516521]
[18]
Goel, A.; Agarwal, N.; Singh, F.V.; Sharon, A.; Tiwari, P.; Dixit, M.; Pratap, R.; Srivastava, A.K.; Maulik, P.R.; Ram, V.J. Antihyperglycemic activity of 2-methyl-3,4,5-triaryl-1H-pyrroles in SLM and STZ models. Bioorg. Med. Chem. Lett., 2004, 14(5), 1089-1092.
[http://dx.doi.org/10.1016/j.bmcl.2004.01.009] [PMID: 14980641]
[19]
Mai, A.; Massa, S.; Ragno, R.; Cerbara, I.; Jesacher, F.; Loidl, P.; Brosch, G. 3-(4-Aroyl-1-methyl-1H-2-pyrrolyl)-N-hydroxy-2-alkylamides as a new class of synthetic histone deacetylase inhibitors. 1. Design, synthesis, biological evaluation, and binding mode studies performed through three different docking procedures. J. Med. Chem., 2003, 46(4), 512-524.
[http://dx.doi.org/10.1021/jm021070e] [PMID: 12570373]
[20]
Kashman, Y.; Goldshlager, G.K.; Gravalos, M.D.G.; Schleyer, M. Halitulin, a new cytotoxic alkaloid from the marine sponge Haliclona tulearensis. Tetrahedron Lett., 1999, 40, 997-1000.
[http://dx.doi.org/10.1016/S0040-4039(98)02467-8]
[21]
Huang, X.C.; Xiao, X.; Zhang, Y.K.; Talele, T.T.; Salim, A.A.; Chen, Z.S.; Capon, R.J. Lamellarin O, a pyrrole alkaloid from an Australian marine sponge, Ianthella sp., reverses BCRP mediated drug resistance in cancer cells. Mar. Drugs, 2014, 12(7), 3818-3837.
[http://dx.doi.org/10.3390/md12073818] [PMID: 24979269]
[22]
Papaetis, G.S.; Syrigos, K.N. Sunitinib: a multitargeted receptor tyrosine kinase inhibitor in the era of molecular cancer therapies. BioDrugs, 2009, 23(6), 377-389.
[http://dx.doi.org/10.2165/11318860-000000000-00000] [PMID: 19894779]
[23]
Härri, E.; Loeffler, W.; Sigg, H.P.; Stähelin, H.; Tamm, C;Ch,S.; Wiesinger, D. Über die verrucarine und roridine, eine gruppe von cytostatisch hochwirksamen antibiotica aus Myrothecium-arten. Helv. Chim. Acta, 1962, 45, 839-853.
[http://dx.doi.org/10.1002/hlca.19620450314]
[24]
Williamson, N.R.; Simonsen, H.T.; Ahmed, R.A.; Goldet, G.; Slater, H.; Woodley, L.; Leeper, F.J.; Salmond, G.P.C. Biosynthesis of the red antibiotic, prodigiosin, in Serratia: identification of a novel 2-Methyl-3-N-Amyl-Pyrrole (MAP) assembly pathway, definition of the terminal condensing enzyme, and implications for undecylprodigiosin biosynthesis in Streptomyces. Mol. Microbiol., 2005, 56(4), 971-989.
[http://dx.doi.org/10.1111/j.1365-2958.2005.04602.x] [PMID: 15853884]
[25]
Williamson, N.R.; Fineran, P.C.; Gristwood, T.; Chawrai, S.R.; Leeper, F.J.; Salmond, G.P. Anticancer and immunosuppressive properties of bacterial prodiginines. Future Microbiol., 2007, 2(6), 605-618.
[http://dx.doi.org/10.2217/17460913.2.6.605] [PMID: 18041902]
[26]
Basit, F.; Cristofanon, S.; Fulda, S. Obatoclax (GX15-070) triggers necroptosis by promoting the assembly of the necrosome on autophagosomal membranes. Cell Death Differ., 2013, 20(9), 1161-1173.
[http://dx.doi.org/10.1038/cdd.2013.45] [PMID: 23744296]
[27]
Gribble, G.W. Comprehensive Heterocyclic Chemistry, 2nd ed; Elsevier Science Ltd.: Hanover, 1996.
[28]
Kang, S.Y.; Park, E.J.; Park, W.K.; Kim, H.J.; Choi, G.; Jung, M.E.; Seo, H.J.; Kim, M.J.; Pae, A.N.; Kim, J.; Lee, J. Further optimization of novel pyrrole 3-carboxamides for targeting serotonin 5-HT(2A), 5-HT(2C), and the serotonin transporter as a potential antidepressant. Bioorg. Med. Chem., 2010, 18(16), 6156-6169.
[http://dx.doi.org/10.1016/j.bmc.2010.06.037] [PMID: 20637635]
[29]
Patil, V.M.; Sinha, R.; Masand, N.; Jain, J. Synthesis and anticonvulsant activities of small N-substituted 2,5-dimethyl pyrrole and bipyrrole. Dig. J. Nanomater. Biostruct., 2009, 4, 471-477.
[30]
Carson, J.R.; Carmosin, R.J.; Pitis, P.M.; Vaught, J.L.; Almond, H.R.; Stables, J.P.; Wolf, H.H.; Swinyard, E.A.; White, H.S. Aroyl(aminoacyl)pyrroles, a new class of anticonvulsant agents. J. Med. Chem., 1997, 40(11), 1578-1584.
[http://dx.doi.org/10.1021/jm9606655] [PMID: 9171868]
[31]
Gourley, B.S.; Molesworth, P.P.; Rayan, J.H.; Smith, J.A. A new and high yielding synthesis of unstable pyrroles via a modified Clauson-Kaas reaction. Tetrahedron Lett., 2006, 47, 799-801.
[http://dx.doi.org/10.1016/j.tetlet.2005.11.104]
[32]
Rivera, S.; Bandyopadhyay, D.; Banik, B.K. Facile synthesis of N-substituted pyrroles via microwave-induced bismuth nitrate-catalyzed reaction. Tetrahedron Lett., 2009, 50, 5445-5448.
[http://dx.doi.org/10.1016/j.tetlet.2009.06.002]
[33]
Abid, M.; Landge, S.M.; Torok, B. An efficient and rapid synthesis of N-substituted pyrroles by microwave assisted solid acid catalysis. Org. Prep. Proced. Int., 2009, 38, 495-500.
[http://dx.doi.org/10.1080/00304940609356444]
[34]
Wilson, M.A.; Filzen, G.; Welmaker, G.S. A microwave-assisted, green procedure for the synthesis of N-aryl sulfonyl and N-aryl pyrroles. Tetrahedron Lett., 2009, 50, 4807-4809.
[http://dx.doi.org/10.1016/j.tetlet.2009.06.079]
[35]
Abid, M.; Teixeira, L.; Török, B. Triflic acid controlled successive annelation of aromatic sulfonamides: an efficient one-pot synthesis of N-sulfonyl pyrroles, indoles and carbazoles. Tetrahedron Lett., 2007, 48(23), 4047-4050.
[http://dx.doi.org/10.1016/j.tetlet.2007.04.021] [PMID: 19629194]
[36]
Cárdenas, R.A.V.; Leal, B.O.Q.; Reddy, A.; Bandyopadhyay, D.; Banik, B.K. Microwave-assisted polystyrene sulfonate-catalyzed synthesis of novel pyrroles. Org. Med. Chem. Lett., 2012, 2(1), 1-6.
[http://dx.doi.org/10.1186/2191-2858-2-24] [PMID: 22726766]
[37]
Sarvari, M.H.; Derikvandi, S.N.; Jarrahpour, A.; Heiran, R. Nano sulfated Titania as a heterogeneous solid acid catalyst for the synthesis of pyrroles by Clauson-Kaas condensation under solvent-free conditions. Chem. Heterocycl. Compd., 2014, 49, 1732-1739.
[http://dx.doi.org/10.1007/s10593-014-1425-3]
[38]
Alizadeh, A.; Masrouri, H.; Rostamnia, S.; Movahedi, F. One-step synthesis of dialkyl 2-[(4-methylphenyl)sulfonyl]-1H-pyrrole-3,4-dicarboxylates by reaction of acetylenedicarboxylates with ‘Tosylmethyl Isocyanide’ (TsMIC) and triphenylphosphine. Helv. Chim. Acta, 2006, 89, 923-926.
[http://dx.doi.org/10.1002/hlca.200690095]
[39]
Galliford, C.V.; Scheidt, K.A. Catalytic multicomponent reactions for the synthesis of N-aryl trisubstituted pyrroles. J. Org. Chem., 2007, 72(5), 1811-1813.
[http://dx.doi.org/10.1021/jo0624086] [PMID: 17256992]
[40]
Kassaee, M.Z.; Masrouria, H.; Movahedi, F.; Partov, T. One‐pot four‐component synthesis of tetrasubstituted pyrroles. Helv. Chim. Acta, 2008, 91, 227-331.
[http://dx.doi.org/10.1002/hlca.200890027]
[41]
Yavari, I.; Kowsari, E. Efficient and green synthesis of tetrasubstituted pyrroles promoted by task-specific basic ionic liquids as catalyst in aqueous media. Mol. Divers., 2009, 13(4), 519-528.
[http://dx.doi.org/10.1007/s11030-009-9146-8] [PMID: 19381850]
[42]
Yavari, I.; Kowsari, E. Task-specific basic ionic liquid: a reusable and green catalyst for one-pot synthesis of highly functionalized pyrroles in aqueous media. Synlett, 2008, 6, 897-899.
[http://dx.doi.org/10.1055/s-2008-1042912]
[43]
Ghabraie, E.; Balalaie, S.; Bararjanian, M.; Bijanzadeh, H.R.; Rominger, F. An efficient one-pot synthesis of tetra-substituted pyrroles. Tetrahedron, 2011, 67, 5415-5420.
[http://dx.doi.org/10.1016/j.tet.2011.05.076]
[44]
Han, Y.; Sun, Y.; Sun, J.; Yan, C.G. Efficient synthesis of pentasubstituted pyrroles via one-pot reactions of arylamines, acetylenedicarboxylates, and 3-phenacylideneoxindoles. Tetrahedron, 2012, 68, 8256-8260.
[http://dx.doi.org/10.1016/j.tet.2012.07.056]
[45]
Feng, X.; Wang, Q.; Lin, W.; Dou, G.L.; Huang, Z.B.; Shi, D.Q. Highly efficient synthesis of polysubstituted pyrroles via four-component domino reaction. Org. Lett., 2013, 15(10), 2542-2545.
[http://dx.doi.org/10.1021/ol4010382] [PMID: 24490761]
[46]
Khan, A.T.; Ghosh, A.; Khan, M.M. One-pot four-component domino reaction for the synthesis of substituted dihydro-2-oxypyrrole catalyzed by molecular iodine. Tetrahedron Lett., 2012, 53, 2622-2626.
[http://dx.doi.org/10.1016/j.tetlet.2012.03.046]
[47]
Sajadikhah, S.S.; Hazer, N.; Maghsoodlou, M.T.; Khorassani, S.M.H.; Beigbabaei, A.; Al Willis, A.C. (H2PO4)3 as an efficient and reusable catalyst for the multi-component synthesis of highly functionalized piperidines and dihydro-2-oxypyrroles. Iran. Chem. Soc., 2013, 10, 863-871.
[http://dx.doi.org/10.1007/s13738-013-0222-8]
[48]
Sajadikhah, S.S.; Hazeri, N.; Maghsoodlou, M.T.; Khorassani, S.M.H.; Barani, K.K. A one-pot multi-component synthesis of N-aryl-3-aminodihydropyrrol-2-one-4-carboxylates catalysed by oxalic acid dehydrate. Chem. Res., 2013, 37, 40-42.
[http://dx.doi.org/10.3184/174751912X13547952669204]
[49]
Alangi, S.Z.S.; Hossaini, Z.; Charati, F.R. Synthesis of highly functionalized pyrroles from primary amines and activated acetylenes in water. Chin. Chem. Lett., 2012, 23, 1119-1121.
[http://dx.doi.org/10.1016/j.cclet.2012.06.042]
[50]
Ardakani, H.A.; Noei, M.; Tabarzad, A. Facile synthesis of N-(arylsulfonyl)-4-ethoxy-5-oxo-2,5-dihydro-1H-pyrolle-2,3-dicarboxylates by one-pot three component reaction. Chin. Chem. Lett., 2012, 23, 45-48.
[http://dx.doi.org/10.1016/j.cclet.2011.09.010]
[51]
Rana, S.; Brown, M. Dutta.; Bhaumik, A.; Mukhopadhyay, C. Site-selective multicomponent synthesis of densely substituted 2-oxo dihydropyrroles catalyzed by clean, reusable, and heterogeneous TiO2 nanopowder. Tetrahedron Lett., 2013, 54, 1371-1379.
[http://dx.doi.org/10.1016/j.tetlet.2012.12.109]
[52]
Zhao, M.N.; Ren, Z.H.; Wang, Y.Y.; Guan, Z.H. Copper-promoted oxidative coupling of enamides and alkynes for the synthesis of substituted pyrroles. Chemistry, 2014, 20(7), 1839-1842.
[http://dx.doi.org/10.1002/chem.201304565] [PMID: 24453126]
[53]
Reddy, L.M.; Chandrashekar, P.; Reddy, A.R.; Reddy, C.K. Synthesis of polysubstituted pyrroles in aqueous medium directly from nitro compounds. Russ. J. Gen. Chem., 2015, 85, 155-161.
[http://dx.doi.org/10.1134/S1070363215010272]
[54]
Zarei, M.; Sajadikhah, S.S. Green and facile synthesis of dihydropyrrol-2-ones and highly substituted piperidines using Ethylenediammonium Diformate (EDDF) as a reusable catalyst. Res. Chem. Intermed., 2016, 42, 7005-7016.
[http://dx.doi.org/10.1007/s11164-016-2512-0]
[55]
Kangani, M.; Maghsoodlou, M.; Hazeri, N. Vitamin B12: an efficient type catalyst for the one-pot synthesis of 3, 4, 5-trisubstituted furan-2 (5H)-ones and N-aryl-3-aminodihydropyrrol-2-one-4-carboxylates. Chin. Chem. Lett., 2016, 27, 66-70.
[http://dx.doi.org/10.1016/j.cclet.2015.07.025]
[56]
Soltani, M.; Baltork, I.M.; Khosropour, A.R.; Moghadam, M.; Tangestaninejad, S.; Mirkhani, V. Vitamin B12: an efficient type catalyst for the one-pot synthesis of 3,4,5-trisubstituted furan-2(5H)-ones and N-aryl-3-aminodihydropyrrol-2-one-4-carboxylates. C. R. Chim., 2016, 19, 381-389.
[http://dx.doi.org/10.1016/j.crci.2015.11.006]
[57]
Dhinakaran, I.; Padmini, V.; Bhuvanesh, N. Chemodivergent, one-pot, multi-component synthesis of pyrroles and tetrahydropyridines under solvent- and catalyst-free conditions using the grinding method. ACS Comb. Sci., 2016, 18(5), 236-242.
[http://dx.doi.org/10.1021/acscombsci.5b00154] [PMID: 26972275]
[58]
Rahmani, F. Darehkordi. Synthesis of trifluoromethylated pyrroles via a one-pot three-component reaction. Synlett, 2017, 28, 1224-1226.
[http://dx.doi.org/10.1055/s-0036-1588732]
[59]
Kangani, M.; Hazeri, N.; Maghsoodlou, M.T. Synthesis of pyrrole and furan derivatives in the presence of lactic acid as a catalyst. J. Saudi Chem. Soc., 2017, 21, 160-164.
[http://dx.doi.org/10.1016/j.jscs.2015.03.002]
[60]
Demir, A.S.; Emrullahoglu, M. Zinc perchlorate catalyzed one-pot amination annulation of α-cyanomethyl-β-ketoesters in water. Regioselective synthesis of 2-aminopyrrole-4-carboxylates. Tetrahedron, 2006, 62, 1452-1458.
[http://dx.doi.org/10.1016/j.tet.2005.11.018]
[61]
Metten, B.; Kostermans, M.; Baelen, G.V.; Smet, M.; Dehaen, W. Synthesis of 5-aryl-2-oxopyrrole derivatives as synthons for highly substituted pyrroles. Tetrahedron, 2006, 62, 6018-6028.
[http://dx.doi.org/10.1016/j.tet.2006.04.005]
[62]
Cadierno, V.; Gimeno, J.; Nebra, N. One-pot three-component catalytic synthesis of fully substituted pyrroles from readily available propargylic alcohols, 1,3-dicarbonyl compounds and primary amines. Chemistry, 2007, 13(35), 9973-9981.
[http://dx.doi.org/10.1002/chem.200701132] [PMID: 17854104]
[63]
Wang, Y-F.; Toh, K.K.; Chiba, S.; Narasaka, K. Mn(III)-catalyzed synthesis of pyrroles from vinyl azides and 1,3-dicarbonyl compounds. Org. Lett., 2008, 10(21), 5019-5022.
[http://dx.doi.org/10.1021/ol802120u] [PMID: 18842053]
[64]
Alizadeh, A.; Babaki, M.; Zohreh, N. Solvent-free synthesis of penta-substituted pyrroles: one-pot reaction of amine, alkyl acetoacetate, and fumaryl chloride. Tetrahedron, 2009, 65, 1704-1707.
[http://dx.doi.org/10.1016/j.tet.2008.12.011]
[65]
Reddy, G.R.; Reddy, T.R.; Joseph, S.C.; Reddy, K.S.; Reddy, L.S.; Kumar, P.M.; Krishna, G.R.; Reddy, C.R.; Rambabu, D.; Kapavarapu, R.; Lakshmi, C.; Meda, T.; Priya, K.K.; Parsad, K.V.L.; Pal, M. Pd-mediated new synthesis of pyrroles: their evaluation as potential inhibitors of phosphodiesterase 4. Chem. Commun., 2011, 47, 7779-7781.
[http://dx.doi.org/10.1039/c1cc12321a]
[66]
Magar, D.R.; Ke, V-J.; Chen, K. Inside cover: Three-component synthesis of functionalized n-protected tetrasubstituted pyrroles by an addition elimination aromatization process. Asian J. Org. Chem., 2013, 2(4), 330-335.
[67]
Umeda, R.; Mashino, T.; Nishiyama, Y. Synthesis of multisubstituted 1H-pyrrole: selenium-catalyzed reaction of γ-nitro substituted carbonyl compounds and carbon monoxide. Tetrahedron, 2014, 70, 4395-4399.
[http://dx.doi.org/10.1016/j.tet.2014.04.061]
[68]
Nandeesh, K.N.; Raghavendra, G.M.; Revanna, C.N.; Vijay, T.A.J.; Rangappa, K.S.; Mantelingu, K. Recyclable, graphite-catalyzed, four-component synthesis of functionalized pyrroles. Synth. Commun., 2014, 44, 1103-1110.
[http://dx.doi.org/10.1080/00397911.2013.848368]
[69]
Gujarathi, S.; Liu, X.; Song, L.; Hendrickson, H.; Zheng, G. A mild and efficient AgSbF6-catalyzed synthesis of fully substituted pyrroles through a sequential propargylation/amination/cycloisomerization reaction. Tetrahedron, 2014, 70(34), 5267-5273.
[http://dx.doi.org/10.1016/j.tet.2014.05.073] [PMID: 25061238]
[70]
Karamthulla, S.; Pal, A.; Khan, M.N.; Choudhury, L.H. Synthesis of pentasubstituted pyrroles via catalyst-free multicomponent reactions. Synlett, 2014, 25, 1926-1936.
[http://dx.doi.org/10.1055/s-0034-1378329]
[71]
Shinde, V.V.; Lee, S.D.; Jeong, Y.S.; Jeong, Y.T. p-Toluenesulfonic acid doped polystyrene (PS-PTSA): solvent-free microwave assisted cross-coupling cyclization-oxidation to build one-pot diversely functionalized pyrrole from aldehyde, amine, active methylene, and nitroalkane. Tetrahedron Lett., 2015, 56, 859-865.
[http://dx.doi.org/10.1016/j.tetlet.2014.12.126]
[72]
Ghashang, M. Zeng, Y.S.; Shaterian, H.R. A convenient method for the preparation of 1,5-diaryl-3-(arylamino)-1H-pyrrol-2(5H)-ones. Chin. J. Chem., 2011, 29, 1851-1855.
[http://dx.doi.org/10.1002/cjoc.201180323]
[73]
Lin, X.; Mao, Z.; Dai, X.; Lu, P.; Wang, Y. A straightforward one-pot multicomponent synthesis of polysubstituted pyrroles. Chem. Commun. , 2011, 47, 6620-6622.
[http://dx.doi.org/10.1039/c1cc11363a]
[74]
Yavari, I. Ghanbari, E.; Hosseinpour, R. Formation of phosphorylated 3H‐pyrroles from Nef-Isocyanide-Perkow adducts and tosylmethyl isocyanide. Helv. Chim. Acta, 2014, 97, 1004-1008.
[http://dx.doi.org/10.1002/hlca.201300400]
[75]
Zheng, Y.; Wang, Y.; Zhou, Z. Organocatalytic multicomponent synthesis of polysubstituted pyrroles from 1,2-diones, aldehydes and arylamines. Chem. Comm., 2015, 51, 16652-16655.
[http://dx.doi.org/10.1039/C5CC05624A]
[76]
Farahi, M.; Davoodi, M.; Tahmasebi, M. A new protocol for one-pot synthesis of tetrasubstituted pyrroles using tungstate sulfuric acid as a reusable solid catalyst. Tetrahedron Lett., 2016, 57, 1582-1584.
[http://dx.doi.org/10.1016/j.tetlet.2016.02.101]
[77]
Bellur, E.; Langer, P. Synthesis of functionalized pyrroles and 6,7-dihydro-1H-indol-4(5H)-ones by reaction of 1,3-dicarbonyl compounds with 2-azido-1,1-diethoxyethane. Tetrahedron Lett., 2006, 47, 2151-2154.
[http://dx.doi.org/10.1016/j.tetlet.2006.01.121]
[78]
Khalili, B.; Jajarmi, P.; Sis, B.E.; Hashemi, M.M. Novel one-pot, three-component synthesis of new 2-alkyl-5-aryl-(1H)-pyrrole-4-ol in water. J. Org. Chem., 2008, 73(6), 2090-2095.
[http://dx.doi.org/10.1021/jo702385n] [PMID: 18290660]
[79]
Dou, G.; Shi, C.; Shi, D. Highly regioselective synthesis of polysubstituted pyrroles through three-component reaction induced by low-valent titanium reagent. J. Comb. Chem., 2008, 10(6), 810-813.
[http://dx.doi.org/10.1021/cc8000844] [PMID: 18729409]
[80]
Liu, X.T.; Huang, L.; Zheng, F.J.; Zhana, Z.P. Indium(III) chloride-catalyzed propargylation/amination/cycloisomerization tandem reaction: one-pot synthesis of highly substituted pyrroles from propargylic alcohols, 1,3-dicarbonyl compounds and primary amines. Adv. Synth. Catal., 2008, 350, 2778-2788.
[http://dx.doi.org/10.1002/adsc.200800473]
[81]
Cadierno, V.; Gimeno, J.; Nebra, N. One-pot three-component synthesis of tetrasubstituted N-H pyrroles from secondary propargylic alcohols, 1,3-dicarbonyl compounds and tert-butyl carbamate. Heterocycl. Chem, 2010, 47, 233-236.
[http://dx.doi.org/10.1002/jhet.301]
[82]
Tamaddon, F.; Farahi, M.; Karam, I.; Mol, B. Molybdate sulfuric acid as a reusable solid catalyst in the synthesis of 2,3,4,5-tetrasubstituted pyrroles via a new one-pot [2+2+1] strategy. Catal. A: Chem., 2012, 356, 85-89.
[http://dx.doi.org/10.1016/j.molcata.2012.01.003]
[83]
Este’vez, V.; Villacampa, M.; Mene’ndez, J.C. Three-component access to pyrroles promoted by the CAN-silver nitrate system under high-speed vibration milling conditions: a generalization of the Hantzsch pyrrole synthesis. Chem. Commun. , 2013, 49, 591-593.
[http://dx.doi.org/10.1039/C2CC38099D]
[84]
Bhat, S.I.; Trived, D.R. A catalyst- and solvent-free three-component reaction for the regioselective one-pot access to polyfunctionalized pyrroles. Tetrahedron Lett., 2013, 54, 5577-5582.
[http://dx.doi.org/10.1016/j.tetlet.2013.07.153]
[85]
Abdelmohsen, S.A.; Ossaily, Y.A.E. One-pot synthesis of 5-[1-substituted 4-acetyl-5-methyl-1H-pyrrol-2-yl)]-8-hydroxyquinolines using DABCO as green catalyst. Heterocycl. Commun., 2015, 21(4), 207-210.
[http://dx.doi.org/10.1515/hc-2015-0033]
[86]
Goyal, S.; Patel, J.K.; Gangar, M.; Kumar, K.; Nair, V.A. Zirconocene dichloride catalysed one-pot synthesis of pyrroles through nitroalkene-enamine assembly. RSC Adv., 2015, 5, 3187-3195.
[http://dx.doi.org/10.1039/C4RA09873K]
[87]
Reddy, G.N.; Likhar, P.R. Green multicomponent reaction for synthesis of trisubstituted pyrroles in ionic liquid [bmim]BF4. Res. Chem. Intermed., 2016, 42, 6873-6879.
[http://dx.doi.org/10.1007/s11164-016-2501-3]
[88]
Yu, Y.; Mang, Z.; Yang, W.; Li, H.; Wang, W. Practical Pd(TFA)2-catalyzed aerobic [4+1] annulation for the synthesis of pyrroles via “one-pot” cascade reactions. Catal., 2016, 6, 169.
[http://dx.doi.org/10.3390/catal6110169]
[89]
Shahvelayati, A.S.; Sabbaghan, M.; Banihashem, S. Sonochemically assisted synthesis of N-substituted pyrroles catalyzed by ZnO nanoparticles under solvent-free conditions. Monatsh. Chem., 2017, 148, 1123-1129.
[http://dx.doi.org/10.1007/s00706-016-1904-6]
[90]
Maiti, S.; Biswas, S.; Jana, U. Iron(III)-catalyzed four-component coupling reaction of 1,3-dicarbonyl compounds, amines, aldehydes, and nitroalkanes: a simple and direct synthesis of functionalized pyrroles. J. Org. Chem., 2010, 75(5), 1674-1683.
[http://dx.doi.org/10.1021/jo902661y] [PMID: 20131775]
[91]
Khan, A.T.; Lal, M.; Bagdi, P.R.; Basha, R.S.; Saravanan, P.; Patra, S. Synthesis of tetra-substituted pyrroles, a potential phosphodiesterase 4B inhibitor, through nickel(II) chloride hexahydrate catalyzed one-pot four-component reaction. Tetrahedron Lett., 2012, 53, 4145-4150.
[http://dx.doi.org/10.1016/j.tetlet.2012.05.133]
[92]
Reddy, G.R.; Reddy, T.R.; Joseph, S.C.; Reddy, K.S.; Pal, M. Iodine catalyzed four-component reaction: a straightforward one-pot synthesis of functionalized pyrroles under metal-free conditions. RSC Adv., 2012, 2, 3387-3395.
[http://dx.doi.org/10.1039/c2ra00982j]
[93]
Saeidian, H.; Abdoli, M.; Salimi, R. One-pot synthesis of highly substituted pyrroles using nano copper oxide as an effective heterogeneous nanocatalyst. C. R. Chim., 2013, 16, 1063-1070.
[http://dx.doi.org/10.1016/j.crci.2013.02.008]
[94]
Atar, A.B.; Jeong, Y.T. Heterogenized tungsten complex: an efficient and high yielding catalyst for the synthesis of structurally diverse tetra substituted pyrrole derivatives via four-component assembly. Tetrahedron Lett., 2013, 54, 5624-5628.
[http://dx.doi.org/10.1016/j.tetlet.2013.08.016]
[95]
Li, B.L.; Li, P.H.; Fang, X.N.; Li, C.X.; Sun, J.L.; Mo, L.P.; Zhang, Z.H. One pot four component synthesis of highly substituted pyrroles in gluconic acid aqueous solution. Tetrahedron, 2013, 69, 7011-7018.
[http://dx.doi.org/10.1016/j.tet.2013.06.049]
[96]
Gupta, N.; Singh, K.N.; Singh, J. Ionic liquid catalyzed one pot four-component coupling reaction for the synthesis of functionalized pyrroles. J. Mol. Liq., 2014, 199, 470-473.
[http://dx.doi.org/10.1016/j.molliq.2014.07.038]
[97]
Gajengi, A.L.; Bhanage, B.M. NiO nanoparticles: efficient catalyst for four component coupling reaction for synthesis of substituted pyrroles. Catal. Lett., 2016, 146, 1341-1347.
[http://dx.doi.org/10.1007/s10562-016-1762-1]
[98]
Li, B.L.; Zhang, M.; Hu, H.C. Du, Xia.; Zhang, Z-H. Nano-CoFe2O4 supported molybdenum as an efficient and magnetically recoverable catalyst for a one-pot, four-component synthesis of functionalized pyrroles. New J. Chem., 2014, 38, 2435-2442.
[http://dx.doi.org/10.1039/c3nj01368e]
[99]
Tang, L.; Yang, M.; Yang, M.; Wang, L.; Dong, W.; Wang, G. Heterogeneous Fe-MIL-101 catalysts for efficient one-pot four-component coupling synthesis of highly substituted pyrroles. New J. Chem., 2015, 39, 4919-4923.
[http://dx.doi.org/10.1039/C5NJ00632E]
[100]
Hu, H.; Liu, Y.; Li, B.; Cui, Z.; Zhang, Z. Deep eutectic solvent based on choline chloride and malonic acid as an efficient and reusable catalytic system for one-pot synthesis of functionalized pyrrole. RSC Adv., 2015, 5, 7720-7728.
[http://dx.doi.org/10.1039/C4RA13577F]
[101]
Moghaddam, F.M.; Foroushani, B.K.; Reza, H. Nickel ferrite nanoparticles: an efficient and reusable nanocatalyst for a neat, one-pot and four-component synthesis of pyrroles. RSC Adv., 2015, 5, 18092-18096.
[http://dx.doi.org/10.1039/C4RA09348H]
[102]
Gajengi, A.L.; Fernandes, C.S.; Bhanage, B.M. Synthesis of Cu2O/Ag nanocomposite and their catalytic application for the one pot synthesis of substituted pyrroles. Mol. Catal., 2018, 451, 13-19.
[http://dx.doi.org/10.1016/j.mcat.2017.10.010]
[103]
Chen, J.; Yang, X.; Liu, M.; Wu, H.; Ding, J. Su, Weike. Approach to synthesis of β-enamino ketones and pyrroles catalyzed by gallium(III) triflate under solvent-free conditions. Synth. Commun., 2009, 39, 4180-4198.
[http://dx.doi.org/10.1080/00397910902898528]
[104]
Veisi, H. Silica Sulfuric Acid (SSA) as a solid acid heterogeneous catalyst for one-pot synthesis of substituted pyrroles under solvent-free conditions at room temperature. Tetrahedron Lett., 2010, 51, 2109-2114.
[http://dx.doi.org/10.1016/j.tetlet.2010.02.052]
[105]
Yuan, S.Z.; Liu, J.; Xu, L. A convenient synthesis of pyrroles catalyzed by acidic resin under solvent-free condition. Chin. Chem. Lett., 2010, 21, 664-668.
[http://dx.doi.org/10.1016/j.cclet.2010.01.038]
[106]
Rahmatpour, A. ZrOCl2•8H2O as a highly efficient, eco-friendly and recyclable Lewis acid catalyst for one-pot synthesis of N‐substituted pyrroles under solvent-free conditions at room temperature. Appl. Organomet. Chem., 2011, 25, 585-590.
[http://dx.doi.org/10.1002/aoc.1806]
[107]
Banik, M.; Ramirez, B.; Reddy, A.; Bandyopadhyay, D.; Banik, B.K. Polystyrenesulfonate-catalyzed synthesis of novel pyrroles through Paal-Knorr reaction. Org. Med. Chem. Lett., 2012, 2(1), 1-4.
[http://dx.doi.org/10.1186/2191-2858-2-11] [PMID: 22452839]
[108]
Darabi, H.R.; Aghapoor, K.; Farahani, A.D.; Mohsenzadeh, F. Vitamin B1 as a metal-free organocatalyst for greener Paal-Knorr pyrrole synthesis. Environ. Chem. Lett., 2012, 10, 369-375.
[http://dx.doi.org/10.1007/s10311-012-0361-7]
[109]
Darabi, H.R.; Poorheravi, M.R.; Aghapoor, K.; Mirzaee, A.; Mohsenzadeh, F.; Asadollahnejad, N.; Taherzadeh, H.; Balavar, Y. Silica-supported antimony(III) chloride as a mild and reusable catalyst for the Paal-Knorr pyrrole synthesis. Environ. Chem. Lett., 2012, 10, 5-12.
[http://dx.doi.org/10.1007/s10311-011-0321-7]
[110]
Chochois, H.; Sauthier, M.; Maerten, E.; Castanet, Y.; Mortreux, A. 1,4-Carbonylative addition of arylboronic acids to methyl vinyl ketone: a new synthetic tool for rapid furan and pyrrole synthesis. Tetrahedron, 2006, 62, 11740-11746.
[http://dx.doi.org/10.1016/j.tet.2006.09.035]
[111]
Jing, X.; Pan, X.; Li, Z.; Bi, X.; Yan, C.; Zhu, H. Organic catalytic multicomponent one-pot synthesis of highly substituted pyrroles. Synth. Commun., 2009, 39, 3833-3844.
[http://dx.doi.org/10.1080/00397910902838953]
[112]
Rueping, M.; Parra, A. Fast, efficient, mild, and metal-free synthesis of pyrroles by domino reactions in water. Org. Lett., 2010, 12(22), 5281-5283.
[http://dx.doi.org/10.1021/ol102247n] [PMID: 20979413]
[113]
Khajuria, R.; Kapoor, K.K. One-pot, solvent-free cascade Michael-reductive cyclization reaction for the synthesis of ethyl 3,5-disubstituted-1H-pyrrole-2-carboxylates under microwave irradiation. Curr. Microw. Chem., 2014, 1, 110-118.
[http://dx.doi.org/10.2174/2213335601666140620221842]
[114]
Kalomode, H.P.; Vadagaonkar, K.S.; Murugan, K.; Prakash, S.; Chaskar, A.C. Deep eutectic solvent: a simple, environmentally benign reaction media for regioselective synthesis of 2,3,4-trisubstituted 1H-pyrroles. RSC Adv., 2015, 5, 35166-35174.
[http://dx.doi.org/10.1039/C5RA03270A]
[115]
Shekarrao, K.; Kaishap, P.P.; Gogoi, S.; Boruaha, R.C. Palladium-catalyzed one‐pot Sonogashira coupling, exo-dig cyclization and hydride transfer reaction: synthesis of pyridine-substituted pyrroles. Adv. Synth. Catal., 2015, 357, 1187-1192.
[http://dx.doi.org/10.1002/adsc.201401117]
[116]
Harrison, T.J.; Kozak, J.A.; Pané, M.C.; Dake, G.R. Pyrrole synthesis catalyzed by AgOTf or cationic Au(I) complexes. J. Org. Chem., 2006, 71(12), 4525-4529.
[http://dx.doi.org/10.1021/jo060382c] [PMID: 16749784]
[117]
Shindo, M.; Yoshimura, Y.; Hayashi, M.; Soejima, H.; Yoshikawa, T.; Matsumoto, K.; Shishido, K. Synthesis of multisubstituted furans, pyrroles, and thiophenes via ynolates. Org. Lett., 2007, 9(10), 1963-1966.
[http://dx.doi.org/10.1021/ol0705200] [PMID: 17439135]
[118]
Cy, D.J.; Arndtsen, B.A. A new use of Wittig-type reagents as 1,3-dipolar cycloaddition precursors and in pyrrole synthesis. J. Am. Chem. Soc., 2007, 129, 12366-12367.
[http://dx.doi.org/10.1021/ja074330w] [PMID: 17880218]
[119]
Cyr, D.J.S.; Martin, N.; Arndtsen, B.A. Direct synthesis of pyrroles from imines, alkynes, and acid chlorides: an isocyanide-mediated reaction. Org. Lett., 2007, 9(3), 449-452.
[http://dx.doi.org/10.1021/ol062773j] [PMID: 17249784]
[120]
Lu, Y.; Arndtsen, B.A. Palladium catalyzed synthesis of Münchnones from α-amidoethers: a mild route to pyrroles. Angew. Chem. Int. Ed., 2008, 120, 5510-5513.
[http://dx.doi.org/10.1002/ange.200801385]
[121]
Chen, X.; Hou, L.; Li, X. An easy one-pot synthesis of tetrasubstituted 3-alkynylpyrroles via multicomponent coupling reaction. Synlett, 2009, 5, 828-832.
[122]
Ngwerume, S.; Camp, J.E. Synthesis of highly substituted pyrroles via nucleophilic catalysis. J. Org. Chem., 2010, 75(18), 6271-6274.
[http://dx.doi.org/10.1021/jo1011448] [PMID: 20718448]
[123]
Liu, X.T.; Hao, L.; Lin, M.; Chen, L.; Zhan, Z.P. One-pot highly efficient synthesis of substituted pyrroles and N-bridgehead pyrroles by zinc-catalyzed multicomponent reaction. Org. Biomol. Chem., 2010, 8(13), 3064-3072.
[http://dx.doi.org/10.1039/c003885g] [PMID: 20480096]
[124]
Wang, T.; Chen, X.L.; Chen, L.; Zhan, Z.P. Atom-economical chemoselective synthesis of 1,4-diynes and polysubstituted furans/pyrroles from propargyl alcohols and terminal alkynes. Org. Lett., 2011, 13(13), 3324-3327.
[http://dx.doi.org/10.1021/ol201054z] [PMID: 21648402]
[125]
Shen, J.; Cheng, G.; Cui, X. “One pot” regiospecific synthesis of polysubstituted pyrroles from benzylamines and ynones under metal free conditions. Chem. Commun. , 2013, 49, 10641-10643.
[http://dx.doi.org/10.1039/c3cc43844a]
[126]
Hu, Y.; Wang, C.; Wang, D.; Wu, F.; Wan, B. Synthesis of tetrasubstituted pyrroles from terminal alkynes and imines. Org. Lett., 2013, 15(12), 3146-3149.
[http://dx.doi.org/10.1021/ol401369d] [PMID: 23745688]
[127]
Miura, T.; Hiraga, K.; Biyajima, T.; Nakamuro, T.; Murakami, M. Regiocontrolled synthesis of polysubstituted pyrroles starting from terminal alkynes, sulfonyl azides, and allenes. Org. Lett., 2013, 15, 3298-3301.
[http://dx.doi.org/ 10.1021/ol401340u]
[128]
Kim, C.E.; Park, S.; Eom, D.; Seo, B.; Lee, P.H. Synthesis of pyrroles from terminal alkynes, N-sulfonyl azides, and alkenyl alkyl ethers through 1-sulfonyl-1,2,3-triazoles. Org. Lett., 2014, 16(7), 1900-1903.
[http://dx.doi.org/10.1021/ol500718s] [PMID: 24660875]
[129]
Zhao, M.N.; Ren, Z.H.; Wang, Y.Y.; Guan, Z.H. Pd-catalyzed oxidative coupling of enamides and alkynes for synthesis of substituted pyrroles. Org. Lett., 2014, 16(2), 608-611.
[http://dx.doi.org/10.1021/ol403517p] [PMID: 24404972]
[130]
Li, X.; Chen, M.; Xie, X.; Sun, N.; Li, S.; Liu, Y. Synthesis of multiple-substituted pyrroles via gold(I)-catalyzed hydroamination/cyclization cascade. Org. Lett., 2015, 17(12), 2984-2987.
[http://dx.doi.org/10.1021/acs.orglett.5b01281] [PMID: 26030605]
[131]
Zhang, Z.; Zhang, F.; Wang, H.; Wu, H.; Duan, X.; Liu, Q.; Liu, T.; Zhang, G. Catalyst-free domino reaction of 1-acryloyl-1-N-arylcarbamylcyclopropanes with amines: one-pot approach to 2,3,6,7-tetrahydro-1h-pyrrolo[3,2-c]pyridin-4(5H)-ones. Adv. Synth. Catal., 2015, 357(12), 2681-2686.
[http://dx.doi.org/10.1002/adsc.201500251]
[132]
Wang, G.; Rongxing, C.; Wu, M.; Sun, S.; Luo, X.; Chen, Z.; Guo, H.; Chong, C.; Xing, Y. Efficient one-pot synthesis of 1, 3-dihydro-2H-pyrrol-2-one derivatives via aza-oxyallylic cations. Tetrahedron Lett., 2017, 58, 847-850.
[http://dx.doi.org/10.1016/j.tetlet.2017.01.048]
[133]
Kuzmin, A.V.; Shabalin, D.A. Superbase-catalyzed domino 3H-pyrroles synthesis from ketoximes and acetylene: DFT study vs experiment. J. Phys. Org., 2018, 31(6)e3829
[http://dx.doi.org/10.1002/poc.3829]
[134]
Kardile, R.D.; Kale, B.S.; Sharma, P.; Liu, R.S. Gold-catalyzed [4 + 1]-annulation reactions between 1,4-diyn-3-ols and isoxazoles to construct a pyrrole core. Org. Lett., 2018, 20(13), 3806-3809.
[http://dx.doi.org/10.1021/acs.orglett.8b01398] [PMID: 29920102]
[135]
Khafizova, L.O.; Shaibakova, M.G.; Rikhter, N.A.; Tyumkina, T.V.; Dzhemilev, U.M. One-pot synthesis of 2,3,5-substituted 1H-pyrroles via the reaction of terminal acetylenes with nitriles and EtAlCl2 catalyzed by Cp2TiCl2. Tetrahedron, 2019, 75(7), 906-911.
[http://dx.doi.org/10.1016/j.tet.2019.01.006]
[136]
Chiu, H.C.; See, X.Y.; Tonks, I.A. Dative directing group effects in Ti-catalyzed [2+2+1] pyrrole synthesis: chemo- and regioselective alkyne heterocoupling. ACS Catal., 2019, 9(1), 216-223.
[http://dx.doi.org/10.1021/acscatal.8b04669] [PMID: 31768294]
[137]
Watanabe, T.; Mutoh, Y.; Saito, S. Synthesis of lactone-fused pyrroles by ruthenium-catalyzed 1,2-carbon migration-cycloisomerization. Org. Biomol. Chem., 2019, 18(1), 81-85.
[http://dx.doi.org/10.1039/C9OB02363A] [PMID: 31782470]
[138]
López, J.; Cabral, I.V.; deLeón, E.R.; Gómez, C.V.; Delgado, F.; Tamariz, J.; Arrieta, A.; Cossío, F.P.; Vázquez, M.A. Selective synthesis of trisubstituted pyrroles through the reactions of alkynyl Fischer carbene complexes with oxazolones. Org. Biomol. Chem., 2020, 18(3), 538-550.
[http://dx.doi.org/10.1039/C9OB02411E] [PMID: 31872193]