{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T01:43:13Z","timestamp":1760233393065,"version":"build-2065373602"},"reference-count":84,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2021,1,13]],"date-time":"2021-01-13T00:00:00Z","timestamp":1610496000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004329","name":"Javna Agencija za Raziskovalno Dejavnost RS","doi-asserted-by":"publisher","award":["P1-0179"],"award-info":[{"award-number":["P1-0179"]}],"id":[{"id":"10.13039\/501100004329","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>A series of 12 silica gel-bound enaminones and their Cu(II) complexes were prepared and tested for their suitability as heterogeneous catalysts in azomethine imine-alkyne cycloadditions (CuAIAC). Immobilized Cu(II)\u2013enaminone complexes showed promising catalytic activity in the CuAIAC reaction, but these new catalysts suffered from poor reusability. This was not due to the decoordination of copper ions, as the use of enaminone ligands with additional complexation sites resulted in negligible improvement. On the other hand, reusability was improved by the use of 4-aminobenzoic acid linker, attached to 3-aminopropyl silica gel via an amide bond to the enaminone over the more hydrolytically stable N-arylenamine C-N bond. The study showed that silica gel-bound Cu(II)\u2013enaminone complexes are readily available and suitable heterogeneous catalysts for the synthesis of 6,7-dihydro-1H,5H-pyrazolo[1,2-a]pyrazoles.<\/jats:p>","DOI":"10.3390\/molecules26020400","type":"journal-article","created":{"date-parts":[[2021,1,13]],"date-time":"2021-01-13T21:50:54Z","timestamp":1610574654000},"page":"400","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Synthesis of 6,7-Dihydro-1H,5H-pyrazolo[1,2-a]pyrazoles by Azomethine Imine-Alkyne Cycloadditions Using Immobilized Cu(II)-Catalysts"],"prefix":"10.3390","volume":"26","author":[{"given":"Ur\u0161a","family":"\u0160tanfel","sequence":"first","affiliation":[{"name":"Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ve\u010dna pot 113, 1000 Ljubljana, Slovenia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dejan","family":"Slap\u0161ak","sequence":"additional","affiliation":[{"name":"Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ve\u010dna pot 113, 1000 Ljubljana, Slovenia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5186-9879","authenticated-orcid":false,"given":"Uro\u0161","family":"Gro\u0161elj","sequence":"additional","affiliation":[{"name":"Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ve\u010dna pot 113, 1000 Ljubljana, Slovenia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6040-294X","authenticated-orcid":false,"given":"Franc","family":"Po\u017egan","sequence":"additional","affiliation":[{"name":"Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ve\u010dna pot 113, 1000 Ljubljana, Slovenia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8709-9853","authenticated-orcid":false,"given":"Bogdan","family":"\u0160tefane","sequence":"additional","affiliation":[{"name":"Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ve\u010dna pot 113, 1000 Ljubljana, Slovenia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3339-3595","authenticated-orcid":false,"given":"Jurij","family":"Svete","sequence":"additional","affiliation":[{"name":"Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ve\u010dna pot 113, 1000 Ljubljana, Slovenia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,1,13]]},"reference":[{"key":"ref_1","first-page":"529","article-title":"[3+2] Cycloadditions of Azomethine Imines","volume":"103","author":"Svete","year":"2020","journal-title":"Org. 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