{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,20]],"date-time":"2026-10-20T18:18:40Z","timestamp":1792520320554,"version":"4.5.0"},"reference-count":46,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2024,5,19]],"date-time":"2024-05-19T00:00:00Z","timestamp":1716076800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100007514","name":"Universit\u00e0 di Pisa","doi-asserted-by":"publisher","award":["PRA_2022-2023"],"award-info":[{"award-number":["PRA_2022-2023"]}],"id":[{"id":"10.13039\/501100007514","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>A squaramide-based organocatalyst for asymmetric Michael reactions has been tested as a chiral solvating agent (CSA) for 26 carboxylic acids and camphorsulfonic acid, encompassing amino acid derivatives, mandelic acid, as well as some of its analogs, propionic acids like profens (ketoprofen and ibuprofen), butanoic acids and others. In many cases remarkably high enantiodifferentiations at 1H, 13C and 19F nuclei were observed. The interaction likely involves a proton transfer from the acidic substrates to the tertiary amine sites of the organocatalyst, thus allowing for pre-solubilization of the organocatalyst (when a chloroform solution of the substrate is employed) or the simultaneous solubilization of both the catalyst and the substrate. DOSY experiments were employed to evaluate whether the catalyst\u2013substrate ionic adduct was a tight one or not. ROESY experiments were employed to investigate the role of the squaramide unit in the adduct formation. A mechanism of interaction was proposed in accordance with the literature data.<\/jats:p>","DOI":"10.3390\/molecules29102389","type":"journal-article","created":{"date-parts":[[2024,5,20]],"date-time":"2024-05-20T06:31:58Z","timestamp":1716186718000},"page":"2389","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["A Squaramide-Based Organocatalyst as a Novel Versatile Chiral Solvating Agent for Carboxylic Acids"],"prefix":"10.3390","volume":"29","author":[{"ORCID":"https:\/\/orcid.org\/0009-0008-2582-7166","authenticated-orcid":false,"given":"Fabio","family":"Spiaggia","sequence":"first","affiliation":[{"name":"Department of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6735-2711","authenticated-orcid":false,"given":"Gloria","family":"Uccello Barretta","sequence":"additional","affiliation":[{"name":"Department of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6805-3366","authenticated-orcid":false,"given":"Anna","family":"Iuliano","sequence":"additional","affiliation":[{"name":"Department of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0008-1199-7113","authenticated-orcid":false,"given":"Carlo","family":"Baldassari","sequence":"additional","affiliation":[{"name":"Department of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0726-5135","authenticated-orcid":false,"given":"Federica","family":"Aiello","sequence":"additional","affiliation":[{"name":"National Research Council, Institute for Chemical and Physical Processes (CNR-IPCF), Via G. Moruzzi 1, 56124 Pisa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6916-321X","authenticated-orcid":false,"given":"Federica","family":"Balzano","sequence":"additional","affiliation":[{"name":"Department of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,5,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"De Luca, C., Felletti, S., Franchina, F.A., Bozza, D., Compagnin, G., Nosengo, C., Pasti, L., Cavazzini, A., and Catani, M. (2024). Recent Developments in the High-Throughput Separation of Biologically Active Chiral Compounds via High Performance Liquid Chromatography. J. Pharm. Biomed. Anal., 238.","DOI":"10.1016\/j.jpba.2023.115794"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"304","DOI":"10.1021\/acs.analchem.2c04371","article-title":"Recent Advances in Separation and Analysis of Chiral Compounds","volume":"95","author":"Qian","year":"2023","journal-title":"Anal. 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