{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T01:57:05Z","timestamp":1790128625103,"version":"4.0.1"},"reference-count":24,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2025,1,13]],"date-time":"2025-01-13T00:00:00Z","timestamp":1736726400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Ministry and Education and Research (MUR)","award":["2022JM3LZ3"],"award-info":[{"award-number":["2022JM3LZ3"]}]},{"name":"Ministry and Education and Research (MUR)","award":["20225 \u00d7 2FS5"],"award-info":[{"award-number":["20225 \u00d7 2FS5"]}]},{"name":"Ministry and Education and Research (MUR)","award":["P20224TTZF"],"award-info":[{"award-number":["P20224TTZF"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>The utilization of the homogeneous (S)-2-pyrrolidine-tetrazole organocatalyst (Ley catalyst) in the self-condensation of ethyl pyruvate and cross-aldol reactions of ethyl pyruvate donor with non-enolizable pyruvate acceptors, namely the sterically hindered ethyl 3-methyl-2-oxobutyrate or the highly electrophilic methyl 3,3,3-trifluoropyruvate, is described as the key enantioselective step toward the synthesis of the corresponding biologically relevant isotetronic acids featuring a quaternary carbon functionalized with ester and alkyl groups. The transition from homogeneous to heterogeneous flow conditions is also investigated, detailing the fabrication and operation of packed-bed reactors filled with a silica-supported version of the pyrrolidine-tetrazole catalyst (SBA-15 as the matrix).<\/jats:p>","DOI":"10.3390\/molecules30020296","type":"journal-article","created":{"date-parts":[[2025,1,13]],"date-time":"2025-01-13T11:31:31Z","timestamp":1736767891000},"page":"296","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Organocatalytic Packed-Bed Reactors for the Enantioselective Flow Synthesis of Quaternary Isotetronic Acids by Direct Aldol Reactions of Pyruvates"],"prefix":"10.3390","volume":"30","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7039-455X","authenticated-orcid":false,"given":"Lorenzo","family":"Poletti","sequence":"first","affiliation":[{"name":"Department of Environmental and Prevention Sciences, University of Ferrara, Via L. Borsari, 46, 44121 Ferrara, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8162-6782","authenticated-orcid":false,"given":"Carmela","family":"De Risi","sequence":"additional","affiliation":[{"name":"Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Via L. Borsari, 46, 44121 Ferrara, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0016-290X","authenticated-orcid":false,"given":"Daniele","family":"Ragno","sequence":"additional","affiliation":[{"name":"Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Via L. Borsari, 46, 44121 Ferrara, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2591-9633","authenticated-orcid":false,"given":"Graziano","family":"Di Carmine","sequence":"additional","affiliation":[{"name":"Department of Environmental and Prevention Sciences, University of Ferrara, Via L. Borsari, 46, 44121 Ferrara, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Riccardo","family":"Tassoni","sequence":"additional","affiliation":[{"name":"Institute for Organic Synthesis and Photoreactivity of the Italian National Research Council, Area della Ricerca di Bologna, Via P. Gobetti, 101, 40129 Bologna, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8303-5441","authenticated-orcid":false,"given":"Alessandro","family":"Massi","sequence":"additional","affiliation":[{"name":"Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Via L. Borsari, 46, 44121 Ferrara, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3937-9671","authenticated-orcid":false,"given":"Paolo","family":"Dambruoso","sequence":"additional","affiliation":[{"name":"Institute for Organic Synthesis and Photoreactivity of the Italian National Research Council, Area della Ricerca di Bologna, Via P. Gobetti, 101, 40129 Bologna, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,1,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"311","DOI":"10.1002\/(SICI)1521-3765(19980210)4:2<311::AID-CHEM311>3.0.CO;2-L","article-title":"Enantioselective Synthesis of Protected Isotetronic Acids","volume":"4","author":"Enders","year":"1998","journal-title":"Chem. Eur. J."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Anderson, J.R., Edwards, R.L., and Whalley, A.J.S. (1982). Metabolites of the Higher Fungi. Part 19. Serpenone, 3-Methoxy-4-Methyl-5-Prop-1-Enylfuran-2(5H)-One, a New \u03b3-Butyrolactone from the Fungus Hypoxylon Serpens (Barrons Strain) (Persoon Ex Fries) Kickx. J. Chem. Soc. 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