{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,16]],"date-time":"2025-10-16T00:57:58Z","timestamp":1760576278870,"version":"build-2065373602"},"reference-count":56,"publisher":"Wiley","issue":"3","license":[{"start":{"date-parts":[[2023,12,18]],"date-time":"2023-12-18T00:00:00Z","timestamp":1702857600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["chemistry-europe.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Eur J Org Chem"],"published-print":{"date-parts":[[2024,1,15]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>Nitrile ylides are 1,3\u2010dipolar species with structures that are commonly described by propargylic and\/or allenic resonance forms. Nevertheless, certain nitrile ylides exhibit a tendency to form dimers, suggesting the existence of structures characterized by an important carbenic contribution. To address the nitrile ylide carbenic nature, here we investigate two derivatives with OH and NH<jats:sub>2<\/jats:sub> electron\u2010donating substituents. These nitrile ylides were generated in cryogenic matrices by UV\u2010irradiation of 3\u2010hydroxy\u2010 and 3\u2010amino\u2010isoxazole precursors and were found to photoisomerize to the corresponding oxazoles. The IR spectral characterization of the photogenerated nitrile ylides reveals the absence of the characteristic strong \u03bd<jats:sub>as<\/jats:sub>(CNC) absorption, which is associated with allenic and propargylic type structures. Computed geometries for the two experimentally investigated nitrile ylides and for analogues with different substituents at C3 and C1, together with NBO and NRT electronic structure analyses, performed at the CCSD(T) level of theory, reveal substantial carbenic character exclusively for nitrile ylides bearing OH and NH<jats:sub>2<\/jats:sub> substituents at C3. As a whole, the results shed light on the factors determining the structural features of nitrile ylides, which play a major role in defining the reactivity of these important elusive compounds.<\/jats:p>","DOI":"10.1002\/ejoc.202301103","type":"journal-article","created":{"date-parts":[[2023,11,28]],"date-time":"2023-11-28T11:06:31Z","timestamp":1701169591000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["On the Carbenic Nature of Nitrile Ylides: Experimental and Computational Characterization of Hydroxy and Amino Nitrile Ylides"],"prefix":"10.1002","volume":"27","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8511-1230","authenticated-orcid":false,"given":"Cl\u00e1udio M.","family":"Nunes","sequence":"first","affiliation":[{"name":"University of Coimbra CQC-IMS Department of Chemistry  3004-535 Coimbra Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5953-976X","authenticated-orcid":false,"given":"A. J.","family":"Lopes Jesus","sequence":"additional","affiliation":[{"name":"University of Coimbra CQC-IMS Faculty of Pharmacy  3004-295 Coimbra Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5782-8819","authenticated-orcid":false,"given":"M\u00e1rio T. S.","family":"Rosado","sequence":"additional","affiliation":[{"name":"University of Coimbra CQC-IMS Department of Chemistry  3004-535 Coimbra Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8264-6854","authenticated-orcid":false,"given":"Rui","family":"Fausto","sequence":"additional","affiliation":[{"name":"University of Coimbra CQC-IMS Department of Chemistry  3004-535 Coimbra Portugal"},{"name":"Istanbul Kultur University Faculty Sciences and Letters Department of Physics  34158 Bakirkoy, Istanbul Turkey"}]}],"member":"311","published-online":{"date-parts":[[2023,12,18]]},"reference":[{"key":"e_1_2_9_1_1","first-page":"2399","volume":"53","author":"Livingstone K.","year":"2021","journal-title":"Synth."},{"key":"e_1_2_9_2_1","doi-asserted-by":"publisher","DOI":"10.2174\/138527207780831710"},{"key":"e_1_2_9_3_1","doi-asserted-by":"publisher","DOI":"10.1002\/0471221902.ch7"},{"key":"e_1_2_9_4_1","doi-asserted-by":"publisher","DOI":"10.1021\/acs.orglett.2c02671"},{"key":"e_1_2_9_5_1","doi-asserted-by":"publisher","DOI":"10.1021\/jo500790n"},{"key":"e_1_2_9_6_1","doi-asserted-by":"publisher","DOI":"10.1039\/c3ra44736g"},{"key":"e_1_2_9_7_1","doi-asserted-by":"publisher","DOI":"10.3762\/bjoc.9.201"},{"key":"e_1_2_9_8_1","doi-asserted-by":"publisher","DOI":"10.1039\/c0cc02863k"},{"key":"e_1_2_9_9_1","doi-asserted-by":"publisher","DOI":"10.1021\/ol9018584"},{"key":"e_1_2_9_10_1","doi-asserted-by":"publisher","DOI":"10.1002\/anie.199405271"},{"key":"e_1_2_9_11_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja2118442"},{"key":"e_1_2_9_12_1","doi-asserted-by":"publisher","DOI":"10.1021\/jo500002r"},{"key":"e_1_2_9_13_1","doi-asserted-by":"publisher","DOI":"10.1021\/jo4015672"},{"key":"e_1_2_9_14_1","doi-asserted-by":"publisher","DOI":"10.1039\/C5CC03518J"},{"key":"e_1_2_9_15_1","doi-asserted-by":"publisher","DOI":"10.1002\/ejoc.202300310"},{"key":"e_1_2_9_16_1","doi-asserted-by":"publisher","DOI":"10.1039\/b006582j"},{"key":"e_1_2_9_17_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0009-2614(00)00010-5"},{"key":"e_1_2_9_18_1","doi-asserted-by":"publisher","DOI":"10.1021\/jo990997s"},{"key":"e_1_2_9_19_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja040109x"},{"key":"e_1_2_9_20_1","doi-asserted-by":"publisher","DOI":"10.1002\/cber.19931261024"},{"key":"e_1_2_9_21_1","doi-asserted-by":"publisher","DOI":"10.1021\/j100281a018"},{"key":"e_1_2_9_22_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja00469a049"},{"key":"e_1_2_9_23_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja100512d"},{"key":"e_1_2_9_24_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja800009z"},{"key":"e_1_2_9_25_1","doi-asserted-by":"publisher","DOI":"10.1021\/jo049748g"},{"key":"e_1_2_9_26_1","doi-asserted-by":"publisher","DOI":"10.1002\/ejic.200600577"},{"key":"e_1_2_9_27_1","doi-asserted-by":"publisher","DOI":"10.1021\/jo402875c"},{"key":"e_1_2_9_28_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja00149a034"},{"key":"e_1_2_9_29_1","doi-asserted-by":"publisher","DOI":"10.1002\/ejoc.201501153"},{"key":"e_1_2_9_30_1","doi-asserted-by":"publisher","DOI":"10.1021\/jo301699z"},{"key":"e_1_2_9_31_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja207717k"},{"key":"e_1_2_9_32_1","unstructured":"In the first stages of irradiation of1\u2009aand1\u2009b species2\u2009aand2\u2009bemerge as the major species formed and subsequently their increase develops slower."},{"key":"e_1_2_9_33_1","doi-asserted-by":"publisher","DOI":"10.1039\/C8CC01052H"},{"key":"e_1_2_9_34_1","doi-asserted-by":"publisher","DOI":"10.1002\/poc.3638"},{"key":"e_1_2_9_35_1","doi-asserted-by":"publisher","DOI":"10.1021\/jp110705c"},{"key":"e_1_2_9_36_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.molstruc.2018.04.042"},{"key":"e_1_2_9_37_1","doi-asserted-by":"publisher","DOI":"10.1071\/CH16604"},{"key":"e_1_2_9_38_1","first-page":"413","volume":"70","author":"Cao J.","year":"2017","journal-title":"J. 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