{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,5]],"date-time":"2026-04-05T07:32:09Z","timestamp":1775374329048,"version":"3.50.1"},"reference-count":84,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2024,8,11]],"date-time":"2024-08-11T00:00:00Z","timestamp":1723334400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100006769","name":"Russian Science Foundation","doi-asserted-by":"publisher","award":["24-23-00126"],"award-info":[{"award-number":["24-23-00126"]}],"id":[{"id":"10.13039\/501100006769","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>A new variant of Fisher indole synthesis involving Bronsted acid-catalyzed hydrohydrazination of unactivated terminal and internal acetylenes with arylhydrazines is reported. The use of polyphosphoric acid alone either as the reaction medium or in the presence of a co-solvent appears to provide the required balance for activating the C\u2013C triple bond towards the nucleophilic attack of the hydrazine moiety without unrepairable reactivity loss of the latter due to competing amino group protonation. Additionally, the formal hydration of acetylenes to the corresponding ketones occurs under the same conditions, making it an alternative approach for generating carbonyl groups from alkynes.<\/jats:p>","DOI":"10.3390\/ijms25168750","type":"journal-article","created":{"date-parts":[[2024,8,14]],"date-time":"2024-08-14T03:46:36Z","timestamp":1723607196000},"page":"8750","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Metal-Free, PPA-Mediated Fisher Indole Synthesis via Tandem Hydroamination\u2013Cyclization Reaction between Simple Alkynes and Arylhydrazines"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6644-9949","authenticated-orcid":false,"given":"Alexander V.","family":"Aksenov","sequence":"first","affiliation":[{"name":"Department of Chemistry, North Caucasus Federal University, 1a Pushkin St., 355017 Stavropol, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dinara C.","family":"Makieva","sequence":"additional","affiliation":[{"name":"Department of Chemistry, North Caucasus Federal University, 1a Pushkin St., 355017 Stavropol, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-5597-3941","authenticated-orcid":false,"given":"Rodion A.","family":"Arestov","sequence":"additional","affiliation":[{"name":"Department of Chemistry, North Caucasus Federal University, 1a Pushkin St., 355017 Stavropol, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2675-9093","authenticated-orcid":false,"given":"Nikolai A.","family":"Arutiunov","sequence":"additional","affiliation":[{"name":"Department of Chemistry, North Caucasus Federal University, 1a Pushkin St., 355017 Stavropol, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0727-9652","authenticated-orcid":false,"given":"Dmitrii A.","family":"Aksenov","sequence":"additional","affiliation":[{"name":"Department of Chemistry, North Caucasus Federal University, 1a Pushkin St., 355017 Stavropol, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7125-9066","authenticated-orcid":false,"given":"Nicolai A.","family":"Aksenov","sequence":"additional","affiliation":[{"name":"Department of Chemistry, North Caucasus Federal University, 1a Pushkin St., 355017 Stavropol, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4742-1999","authenticated-orcid":false,"given":"Alexander V.","family":"Leontiev","sequence":"additional","affiliation":[{"name":"Department of Chemistry, North Caucasus Federal University, 1a Pushkin St., 355017 Stavropol, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8083-1407","authenticated-orcid":false,"given":"Inna V.","family":"Aksenova","sequence":"additional","affiliation":[{"name":"Department of Chemistry, North Caucasus Federal University, 1a Pushkin St., 355017 Stavropol, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,8,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"6620","DOI":"10.3390\/molecules18066620","article-title":"Biomedical Importance of Indoles","volume":"18","author":"Kaushik","year":"2013","journal-title":"Molecules"},{"key":"ref_2","first-page":"864","article-title":"Medicinal Perspective of Indole Derivatives: Recent Developments and Structure-Activity Relationship Studies","volume":"21","author":"Kumar","year":"2020","journal-title":"Curr. Drug Targets"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"788","DOI":"10.1039\/D3MD00677H","article-title":"Indole-Containing Pharmaceuticals: Targets, Pharmacological Activities, and SAR Studies","volume":"15","author":"Zeng","year":"2024","journal-title":"RSC Med. Chem."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Gribble, G.W. (2016). Indole Ring Synthesis: From Natural Products to Drug Discovery, Wiley.","DOI":"10.1002\/9781118695692"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"13729","DOI":"10.1039\/D3NJ01488F","article-title":"Indole Frameworks via Transition-Metal-Free Annulation: A Current Perspective","volume":"47","author":"Das","year":"2023","journal-title":"New J. Chem."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1070\/RCR4844","article-title":"Synthesis of Indoles: Recent Advances","volume":"88","author":"Bugaenko","year":"2019","journal-title":"Russ. Chem. Rev."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1467","DOI":"10.1002\/ajoc.201800290","article-title":"Metal-Catalyzed Synthesis of Substituted Indoles","volume":"7","author":"Youn","year":"2018","journal-title":"Asian J. Org. Chem."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"e202300092","DOI":"10.1002\/ajoc.202300092","article-title":"Recent Advances in Indole Synthesis and the Related Alkylation","volume":"12","author":"Ma","year":"2023","journal-title":"Asian J. Org. Chem."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"299","DOI":"10.1080\/00304948.2022.2151810","article-title":"Current Advances in Transition Metal-Free Access to Indoles. A Review","volume":"55","author":"Mathada","year":"2023","journal-title":"Org. Prep. Proced. Int."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"De, S. (2021). Synthesis of Some Heterocyclic Compounds Using Named Reactions. Applied Organic Chemistry, Wiley.","DOI":"10.1002\/9783527828166.ch10"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1039\/C2SC21185H","article-title":"Indole Synthesis\u2014Something Old, Something New","volume":"4","author":"Inman","year":"2013","journal-title":"Chem. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2875","DOI":"10.1021\/cr0505270","article-title":"Practical Methodologies for the Synthesis of Indoles","volume":"106","author":"Humphrey","year":"2006","journal-title":"Chem. Rev."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"33540","DOI":"10.1039\/D1RA05972F","article-title":"Synthesis of Indole Derivatives as Prevalent Moieties Present in Selected Alkaloids","volume":"11","author":"Heravi","year":"2021","journal-title":"RSC Adv."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"52852","DOI":"10.1039\/C7RA10716A","article-title":"Fischer Indole Synthesis Applied to the Total Synthesis of Natural Products","volume":"7","author":"Heravi","year":"2017","journal-title":"RSC Adv."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2596","DOI":"10.1021\/cr300389u","article-title":"Late Transition Metal-Catalyzed Hydroamination and Hydroamidation","volume":"115","author":"Huang","year":"2015","journal-title":"Chem. Rev."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1070\/RCR4983","article-title":"Catalysis and Regioselectivity in Hydrofunctionalization Reactions of Unsaturated Carbon Bonds. Part III","volume":"90","author":"Beletskaya","year":"2021","journal-title":"Russ. Chem. Rev."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1039\/C9QO01315F","article-title":"Recent Advances in the Synthesis of Indoles from Alkynes and Nitrogen Sources","volume":"7","author":"Neto","year":"2020","journal-title":"Org. Chem. Front."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1282","DOI":"10.1002\/ajoc.202100013","article-title":"Recent Developments in the Cyclization of Alkynes and Nitrogen Compounds for the Synthesis of Indole Derivatives","volume":"10","author":"Neto","year":"2021","journal-title":"Asian J. Org. Chem."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2153","DOI":"10.1002\/adsc.200800409","article-title":"Catalytic Synthesis of Indoles from Alkynes","volume":"350","author":"Tillack","year":"2008","journal-title":"Adv. Synth. Catal."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2304","DOI":"10.1002\/anie.200703823","article-title":"Zinc-Promoted Hydrohydrazination of Terminal Alkynes: An Efficient Domino Synthesis of Indoles","volume":"47","author":"Alex","year":"2008","journal-title":"Angew. Chemie Int. Ed."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2015","DOI":"10.1021\/jo402668q","article-title":"Bis(Amidate)Bis(Amido) Titanium Complex: A Regioselective Intermolecular Alkyne Hydroamination Catalyst","volume":"79","author":"Yim","year":"2014","journal-title":"J. Org. Chem."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Pews-Davtyan, A., Tillack, A., Schm\u00f6le, A.-C., Ortinau, S., Frech, M.J., Rolfs, A., and Beller, M. (2010). A New Facile Synthesis of 3-Amidoindole Derivatives and Their Evaluation as Potential GSK-3\u03b2 Inhibitors. Org. Biomol. Chem., 8.","DOI":"10.1039\/b920861e"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"6331","DOI":"10.1039\/c1ob05576c","article-title":"Efficient and Simple Zinc-Mediated Synthesis of 3-Amidoindoles","volume":"9","author":"Beller","year":"2011","journal-title":"Org. Biomol. Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"151430","DOI":"10.1016\/j.tetlet.2019.151430","article-title":"Zn(OTf)2-Catalyzed Arenehydrazination of Protected Propargylamines Leading to 3-Amidoindoles","volume":"61","author":"Vedekhina","year":"2020","journal-title":"Tetrahedron Lett."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"6831","DOI":"10.1002\/ejoc.201001114","article-title":"Mechanistic Dichotomy with Alkynes in the Formal Hydrohydrazination\/Fischer Indolization Tandem Reaction Catalyzed by a Ph3PAuNTf2\/p-TSA Binary System","volume":"2010","author":"Patil","year":"2010","journal-title":"Eur. J. Org. Chem."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"6343","DOI":"10.1021\/ja00016a101","article-title":"Generation, Dative Ligand Trapping, and N-N Bond Cleavage Reactions of the First Monomeric H1-Hydrazido Zirconocene Complex, Cp2Zr=NNPh2. A Zirconium-Mediated Synthesis of Indoles","volume":"113","author":"Walsh","year":"1991","journal-title":"J. Am. Chem. Soc."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1005","DOI":"10.1021\/om700852v","article-title":"Titanium-Catalyzed Hydrohydrazination with Monosubstituted Hydrazines: Catalyst Design, Synthesis, and Reactivity","volume":"27","author":"Banerjee","year":"2008","journal-title":"Organometallics"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2853","DOI":"10.1021\/ol0201052","article-title":"Intermolecular Alkyne Hydroaminations Involving 1,1-Disubstituted Hydrazines","volume":"4","author":"Cao","year":"2002","journal-title":"Org. Lett."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"9541","DOI":"10.1016\/j.tetlet.2004.10.160","article-title":"TiCl4\/t-BuNH2 as the Sole Catalyst for a Hydroamination-Based Fischer Indole Synthesis","volume":"45","author":"Ackermann","year":"2004","journal-title":"Tetrahedron Lett."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"7622","DOI":"10.1016\/j.tet.2005.05.093","article-title":"Convenient Synthesis of Tryptophols and Tryptophol Homologues by Hydroamination of Alkynes","volume":"61","author":"Khedkar","year":"2005","journal-title":"Tetrahedron"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"3123","DOI":"10.1016\/j.tetlet.2004.02.085","article-title":"Efficient One-Pot Synthesis of Tryptamines and Tryptamine Homologues by Amination of Chloroalkynes","volume":"45","author":"Khedkar","year":"2004","journal-title":"Tetrahedron Lett."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1091","DOI":"10.1055\/s-2007-973892","article-title":"Titanium-Catalyzed Hydroamination of Propargyl Alcohol Derivatives: Synthesis of 3-Silyloxy-2-Methylindoles via Hydrohydrazination","volume":"2007","author":"Schwarz","year":"2007","journal-title":"Synlett"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"4525","DOI":"10.1002\/ejoc.200700310","article-title":"A Convenient and General Method for the Synthesis of Indole-2,3-dicarboxylates and 2-Arylindole-3-carboxylates","volume":"2007","author":"Sayyed","year":"2007","journal-title":"Eur. J. Org. Chem."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"5757","DOI":"10.1002\/anie.201101070","article-title":"Zirconium-Catalyzed Multistep Reaction of Hydrazines with Alkynes: A Non-Fischer-Type Pathway to Indoles","volume":"50","author":"Gehrmann","year":"2011","journal-title":"Angew. Chemie Int. Ed."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"12426","DOI":"10.1002\/anie.201306098","article-title":"Indole Synthesis by Rhodium(III)-Catalyzed Hydrazine-Directed C-H Activation: Redox-Neutral and Traceless by N-N Bond Cleavage","volume":"52","author":"Zhao","year":"2013","journal-title":"Angew. Chemie Int. Ed."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"6176","DOI":"10.1021\/ol5030794","article-title":"Rhodium-Catalyzed Oxidative Annulation of Hydrazines with Alkynes Using a Nitrobenzene Oxidant","volume":"16","author":"Li","year":"2014","journal-title":"Org. Lett."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"3806","DOI":"10.1021\/acs.orglett.6b01805","article-title":"Co(III)-Catalyzed, Internal and Terminal Alkyne-Compatible Synthesis of Indoles","volume":"18","author":"Zhou","year":"2016","journal-title":"Org. Lett."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"154722","DOI":"10.1016\/j.tetlet.2023.154722","article-title":"Convenient Synthesis of (Z)-3-(1-Aryl-2-Nitrovinyl)-Indoles","volume":"129","author":"Arutiunov","year":"2023","journal-title":"Tetrahedron Lett."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Aksenov, N.A., Arutiunov, N.A., Aksenov, A.V., Kirilov, N.K., Aksenova, I.V., Aksenov, D.A., Aleksandrova, E.V., Rubin, M., and Kornienko, A. (2023). Synthesis of \u03b2-Carbolines with Electrocyclic Cyclization of 3-Nitrovinylindoles. Int. J. Mol. Sci., 24.","DOI":"10.3390\/ijms241713107"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1115","DOI":"10.1021\/acs.oprd.8b00144","article-title":"An Eco-Friendly Industrial Fischer Indole Cyclization Process","volume":"22","author":"Yang","year":"2018","journal-title":"Org. Process Res. Dev."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"104","DOI":"10.1039\/b200386b","article-title":"The Catalytic Hydroamination of Alkynes","volume":"32","author":"Pohlki","year":"2003","journal-title":"Chem. Soc. Rev."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1407","DOI":"10.1039\/b600981f","article-title":"The Catalytic Hydroamination of Alkynes","volume":"36","author":"Severin","year":"2007","journal-title":"Chem. Soc. Rev."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"6825","DOI":"10.1002\/ejoc.201402300","article-title":"Efficient Anti-Markovnikov-Selective Catalysts for Intermolecular Alkyne Hydroamination: Recent Advances and Synthetic Applications","volume":"2014","author":"Yim","year":"2014","journal-title":"Eur. J. Org. Chem."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"419","DOI":"10.1016\/j.jorganchem.2010.10.027","article-title":"Alkyne Hydroamination Triggered Cyclizations: A Powerful Tool for the Construction of Biologically Important Structural Motifs","volume":"696","author":"Patil","year":"2011","journal-title":"J. Organomet. Chem."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"9139","DOI":"10.1021\/acs.chemrev.2c00482","article-title":"Anti-Markovnikov Intermolecular Hydroamination of Alkenes and Alkynes: A Mechanistic View","volume":"123","author":"Escorihuela","year":"2023","journal-title":"Chem. Rev."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"240","DOI":"10.1021\/acs.accounts.6b00449","article-title":"Base-Mediated Hydroamination of Alkynes","volume":"50","author":"Patel","year":"2017","journal-title":"Acc. Chem. Res."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"4906","DOI":"10.1039\/D0OB00670J","article-title":"Synthesis of Indoles from Alkynes and a Nitrogen Source under Metal-Free Conditions","volume":"18","author":"Neto","year":"2020","journal-title":"Org. Biomol. Chem."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"3795","DOI":"10.1021\/cr0306788","article-title":"Hydroamination: Direct Addition of Amines to Alkenes and Alkynes","volume":"108","author":"Hultzsch","year":"2008","journal-title":"Chem. Rev."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1327","DOI":"10.1021\/acs.oprd.5b00010","article-title":"Nonprecious Metals Catalyzing Hydroamination and C\u2013N Coupling Reactions","volume":"19","author":"Coman","year":"2015","journal-title":"Org. Process Res. Dev."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"1074","DOI":"10.1070\/RCR4953","article-title":"Catalysis and Regioselectivity in Hydrofunctionalization Reactions of Unsaturated Carbon Bonds. Part II. Hydroamination","volume":"89","author":"Beletskaya","year":"2020","journal-title":"Russ. Chem. Rev."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"2017","DOI":"10.1039\/C4CY01716A","article-title":"Recent Advances in Metal Free- and Late Transition Metal-Catalysed Hydroamination of Unactivated Alkenes","volume":"5","author":"Bernoud","year":"2015","journal-title":"Catal. Sci. Technol."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"7588","DOI":"10.1021\/acs.orglett.0c02785","article-title":"Imidazole-Selective Alkyne Hydroamination under Physiological Conditions","volume":"22","author":"Kang","year":"2020","journal-title":"Org. Lett."},{"key":"ref_53","doi-asserted-by":"crossref","unstructured":"Aksenov, A.V., Grishin, I.Y., Aksenov, N.A., Malyuga, V.V., Aksenov, D.A., Nobi, M.A., and Rubin, M. (2021). Electrophilically Activated Nitroalkanes in Synthesis of 3,4-Dihydroquinozalines. Molecules, 26.","DOI":"10.3390\/molecules26144274"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"4289","DOI":"10.1039\/C5OB00131E","article-title":"Benzimidazoles and Benzoxazoles via the Nucleophilic Addition of Anilines to Nitroalkanes","volume":"13","author":"Aksenov","year":"2015","journal-title":"Org. Biomol. Chem."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"1047","DOI":"10.1007\/s11172-019-2518-z","article-title":"Synthesis of 3,4-Dihydroisoquinolines Using Nitroalkanes in Polyphosphoric Acid","volume":"68","author":"Aksenov","year":"2019","journal-title":"Russ. Chem. Bull."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"6636","DOI":"10.1039\/C9RA00976K","article-title":"Electrophilic Activation of Nitroalkanes in Efficient Synthesis of 1,3,4-Oxadiazoles","volume":"9","author":"Aksenov","year":"2019","journal-title":"RSC Adv."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"321","DOI":"10.1021\/cr50020a004","article-title":"Polyphosphoric Acids as a Reagent in Organic Chemistry","volume":"58","author":"Popp","year":"1958","journal-title":"Chem. Rev."},{"key":"ref_58","doi-asserted-by":"crossref","unstructured":"Dodd, J.H. (2001). Polyphosphoric Acid. Encyclopedia of Reagents for Organic Synthesis, John Wiley & Sons, Ltd.","DOI":"10.1002\/047084289X.rp186"},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"1193","DOI":"10.1016\/j.cep.2011.08.009","article-title":"Beneficial Energy-Efficiencies in the Microwave-Assisted Vacuum Preparation of Polyphosphoric Acid","volume":"50","author":"Pinchukova","year":"2011","journal-title":"Chem. Eng. Process. Process Intensif."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"222","DOI":"10.1055\/s-1980-28974","article-title":"Utilization of Polyphosphoric Acid in the Presence of a Co-Solvent","volume":"1980","author":"Guy","year":"1980","journal-title":"Synthesis"},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"197","DOI":"10.1080\/00397911.2015.1114633","article-title":"Silica-Supported Polyphosphoric Acid (PPA-SiO2): An Efficient and Reusable Heterogeneous Catalyst for Ecofriendly Organic Synthesis","volume":"46","author":"Vekariya","year":"2016","journal-title":"Synth. Commun."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"36980","DOI":"10.1039\/C8RA08155G","article-title":"A Nitroalkane-Based Approach to One-Pot Three-Component Synthesis of Isocryptolepine and Its Analogs with Potent Anti-Cancer Activities","volume":"8","author":"Aksenov","year":"2018","journal-title":"RSC Adv."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"e202400895","DOI":"10.1002\/chem.202400895","article-title":"Cross-Coupling Between Aryl Halides and Aryl Alkynes Catalyzed by an Odd Alternant Hydrocarbon","volume":"30","author":"Sil","year":"2024","journal-title":"Chem. Eur. J."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"903","DOI":"10.1039\/C4CC08938C","article-title":"Efficient Hydration of Alkynes through Acid-Assisted Br\u00f8nsted Acid Catalysis","volume":"51","author":"Liang","year":"2015","journal-title":"Chem. Commun."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"2920","DOI":"10.1021\/ie50480a063","article-title":"Reactions of Isopropenyl Acetate","volume":"41","author":"Hagemeyer","year":"1949","journal-title":"Ind. Eng. Chem."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"1121","DOI":"10.1055\/s-2007-966002","article-title":"Catalytic Hydration of Alkynes and Its Application in Synthesis","volume":"2007","author":"Hintermann","year":"2007","journal-title":"Synthesis"},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"120288","DOI":"10.1016\/j.ica.2021.120288","article-title":"Sustainable Hydration of Alkynes Promoted by First Row Transition Metal Complexes. Background, Highlights, and Perspectives","volume":"522","author":"Salvio","year":"2021","journal-title":"Inorganica Chim. Acta"},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"15672","DOI":"10.1021\/jacs.4c03826","article-title":"Silver-Catalyzed (Z)-\u03b2-Fluoro-Vinyl Iodonium Salts from Alkynes: Efficient and Selective Syntheses of Z-Monofluoroalkenes","volume":"146","author":"Sedikides","year":"2024","journal-title":"J. Am. Chem. Soc."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"7430","DOI":"10.1021\/acscatal.8b01706","article-title":"Membrane-Grafted Asymmetric Organocatalyst for an Integrated Synthesis\u2013Separation Platform","volume":"8","author":"Didaskalou","year":"2018","journal-title":"ACS Catal."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"122295","DOI":"10.1016\/j.jorganchem.2022.122295","article-title":"Ionic Liquid Modified Carbon Nanotube Supported Palladium Nanoparticles for Efficient Sonogashira-Hagihara Reaction","volume":"963","author":"Gholinejad","year":"2022","journal-title":"J. Organomet. Chem."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"10347","DOI":"10.1021\/jo301984p","article-title":"Visible-Light-Mediated \u03b1-Arylation of Enol Acetates Using Aryl Diazonium Salts","volume":"77","author":"Hering","year":"2012","journal-title":"J. Org. Chem."},{"key":"ref_72","doi-asserted-by":"crossref","unstructured":"Yu, X., Park, E.-J., Kondratyuk, T.P., Pezzuto, J.M., and Sun, D. (2012). Synthesis of 2-Arylindole Derivatives and Evaluation as Nitric Oxide Synthase and NF\u03baB Inhibitors. Org. Biomol. Chem., 10.","DOI":"10.1039\/c2ob26456k"},{"key":"ref_73","doi-asserted-by":"crossref","first-page":"1062","DOI":"10.1021\/om060965c","article-title":"Intra- and Intermolecular Hydroamination of Alkynes Catalyzed by Ortho-Metalated Iridium Complexes","volume":"26","author":"Lai","year":"2007","journal-title":"Organometallics"},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"16786","DOI":"10.1002\/chem.201503474","article-title":"Through-Space 1,4-Palladium Migration and 1,2-Aryl Shift: Direct Access to Dibenzo[a,c]Carbazoles through a Triple C-H Functionalization Cascade","volume":"21","author":"Bhunia","year":"2015","journal-title":"Chem. Eur. J."},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"4160","DOI":"10.1021\/jo800464u","article-title":"InBr3-Promoted Divergent Approach to Polysubstituted Indoles and Quinolines from 2-Ethynylanilines: Switch from an Intramolecular Cyclization to an Intermolecular Dimerization by a Type of Terminal Substituent Group","volume":"73","author":"Sakai","year":"2008","journal-title":"J. Org. Chem."},{"key":"ref_76","doi-asserted-by":"crossref","first-page":"3294","DOI":"10.1002\/anie.201913656","article-title":"Chiral Br\u00f8nsted Acid from Chiral Phosphoric Acid Boron Complex and Water: Asymmetric Reduction of Indoles","volume":"59","author":"Yang","year":"2020","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"5056","DOI":"10.1002\/anie.200800689","article-title":"Dirhodium(II)-Catalyzed Intramolecular C-H Amination of Aryl Azides","volume":"47","author":"Shen","year":"2008","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1002\/aoc.3253","article-title":"Green and Reusable Homogeneous Oxidative System with Ceric Ammonium Nitrate\/[Imim-PEG 1000-TEMPO] for Efficient Aerobic Oxidation of Alcohols and One-pot Synthesis of Benzimidazoles from Alcohols under Ambient Conditions","volume":"29","author":"Wang","year":"2015","journal-title":"Appl. Organomet. Chem."},{"key":"ref_79","doi-asserted-by":"crossref","first-page":"74","DOI":"10.1002\/adsc.201500734","article-title":"Selective Debromination and A-Hydroxylation of \u03b1-Bromo Ketones Using Hantzsch Esters as Photoreductants","volume":"358","author":"Jung","year":"2016","journal-title":"Adv. Synth. Catal."},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"4936","DOI":"10.1021\/acs.organomet.7b00774","article-title":"A Versatile Ru(II)-NNP Complex Catalyst for the Synthesis of Multisubstituted Pyrroles and Pyridines","volume":"36","author":"Chai","year":"2017","journal-title":"Organometallics"},{"key":"ref_81","doi-asserted-by":"crossref","first-page":"1234","DOI":"10.1021\/acs.orglett.5b03690","article-title":"Direct Oxidation of Aliphatic C\u2013H Bonds in Amino-Containing Molecules under Transition-Metal-Free Conditions","volume":"18","author":"Li","year":"2016","journal-title":"Org. Lett."},{"key":"ref_82","doi-asserted-by":"crossref","first-page":"483","DOI":"10.1002\/jhet.5570420402","article-title":"Synthesis of New Azolyl Azoles and Azinyl Azoles","volume":"42","author":"Elnagdi","year":"2005","journal-title":"J. Heterocycl. Chem."},{"key":"ref_83","doi-asserted-by":"crossref","first-page":"3607","DOI":"10.1002\/adsc.201800612","article-title":"Oxidation of Tertiary Aromatic Alcohols to Ketones in Water","volume":"360","author":"Chen","year":"2018","journal-title":"Adv. Synth. Catal."},{"key":"ref_84","doi-asserted-by":"crossref","first-page":"6810","DOI":"10.1039\/C8NJ00032H","article-title":"MCR-Click Synthesis, Molecular Docking and Cytotoxicity Evaluation of a New Series of Indole\u2013Triazole\u2013Coumarin Hybrid Peptidomimetics","volume":"42","author":"Pathoor","year":"2018","journal-title":"New J. Chem."}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/25\/16\/8750\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T15:34:50Z","timestamp":1760110490000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/25\/16\/8750"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,8,11]]},"references-count":84,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2024,8]]}},"alternative-id":["ijms25168750"],"URL":"https:\/\/doi.org\/10.3390\/ijms25168750","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,8,11]]}}}