{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,14]],"date-time":"2026-08-14T15:02:45Z","timestamp":1786719765472,"version":"build-2736575974"},"reference-count":17,"publisher":"American Chemical Society (ACS)","issue":"32","license":[{"start":{"date-parts":[[2026,8,4]],"date-time":"2026-08-04T00:00:00Z","timestamp":1785801600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003593","name":"Conselho Nacional de Desenvolvimento Cient\u00edfico e Tecnol\u00f3gico","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100003593","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001807","name":"Funda\u00e7\u00e3o de Amparo \u00e0 Pesquisa do Estado de S\u00e3o Paulo","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100001807","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002322","name":"Coordena\u00e7\u00e3o de Aperfei\u00e7oamento de Pessoal de N\u00edvel Superior","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100002322","id-type":"DOI","asserted-by":"publisher"}]},{"name":"MackPesquisa, Universidade Presbiteriana Mackenzie"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,8,14]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>We report the first intrinsic reactivity measurements of four cyclic N,N-diacyliminium ions in Mannich-type reactions. Using MSn experiments (n = 1, 2) performed in the unique, convenient, and gaseous environment of a pentaquadrupole mass spectrometer, we reacted four gaseous five- or six-membered cyclic N,N-diacyliminium ions with allyltrimethylsilane and have established a complete reactivity order, demonstrating that N,N-diacyliminium ions surpass their N-monoacyl counterparts in reactivity. The study also enabled the isolation and characterization of key Mannich intermediates, confirming their bound nature and validating long-standing mechanistic proposals. Calculations have also indicated that the Mannich intermediates for the N,N-diacyliminium ions undergo prompt cyclization, and that therefore the reactions of these N,N-diacyliminium ions with an exocyclic N-acyl group with allyltrimethylsilane form polar [4+ + 2] cycloadducts. These findings provide a fundamental, solvent-free framework for understanding the electrophilic behavior of these key organic ions, completing the reactivity scale for cyclic nonacyl, N-mono-, and N,N-diacyliminium ions.<\/jats:p>","DOI":"10.1021\/acs.joc.6c00237","type":"journal-article","created":{"date-parts":[[2026,8,4]],"date-time":"2026-08-04T16:02:01Z","timestamp":1785859321000},"page":"10798-10806","source":"Crossref","is-referenced-by-count":0,"title":["Intrinsic Reactivity\nof the Elusive Cyclic\n                    <i>N<\/i>\n                    ,\n                    <i>N<\/i>\n                    -Diacyliminium\nIons in Mannich\nReactions: The Complete Reactivity Order for Non,\n                    <i>N<\/i>\n                    -Mono and\n                    <i>N<\/i>\n                    ,\n                    <i>N<\/i>\n                    -Diacyliminium\nIons"],"prefix":"10.1021","volume":"91","author":[{"given":"Luiz Alberto B.","family":"de Moraes","sequence":"first","affiliation":[{"name":"University of Sao Paulo , , , ,","place":["Ribeirao Preto, Sao Paulo, Brazil, 14040-901"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Adriano","family":"Reis","sequence":"additional","affiliation":[{"name":"Mackenzie Presbyterian University and MackGraphe - Mackenzie Institute for Research in Graphene and Nanotechnologies, Mackenzie Presbyterian Institute , , , ,","place":["Sa\u0303o Paulo, Sa\u0303o Paulo, Brazil, 01302-907"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marcelo G. Montes","family":"D\u2019Oca","sequence":"additional","affiliation":[{"name":"Federal University of Parana\u0301 , , , ,","place":["Curitiba, Parana\u0301, Brazil, 81531-990"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cristina M.","family":"Schuch","sequence":"additional","affiliation":[{"name":"University of Campinas , , , ,","place":["Campinas, Sa\u0303o Paulo, Brazil, 13083-970"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5919-7763","authenticated-orcid":true,"given":"Ronaldo A.","family":"Pilli","sequence":"additional","affiliation":[{"name":"University of Campinas , , , ,","place":["Campinas, Sa\u0303o Paulo, Brazil, 13083-970"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9448-9518","authenticated-orcid":true,"given":"Rodinei","family":"Augusti","sequence":"additional","affiliation":[{"name":"Federal University of Minas Gerais , , , ,","place":["Belo Horizonte, Minas Gerais, Brazil, 31270-901"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4716-4080","authenticated-orcid":true,"given":"Marcos N.","family":"Eberlin","sequence":"additional","affiliation":[{"name":"Mackenzie Presbyterian University and MackGraphe - Mackenzie Institute for Research in Graphene and Nanotechnologies, Mackenzie Presbyterian Institute , , , ,","place":["Sa\u0303o Paulo, Sa\u0303o Paulo, Brazil, 01302-907"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2026,8,4]]},"reference":[{"key":"2026081410103216900_cit1","doi-asserted-by":"publisher","first-page":"113","DOI":"10.1002\/(SICI)1098-2787(1997)16:3&lt;113::AID-MAS1&gt;3.0.CO;2-K","article-title":"Triple-Stage\nPentaquadrupole (QqQqQ) Mass Spectrometry and Ion\/Molecule Reactions","volume":"16","author":"Eberlin","year":"1997","journal-title":"Mass Spectrom. 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