{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,19]],"date-time":"2026-02-19T03:09:35Z","timestamp":1771470575475,"version":"3.50.1"},"reference-count":40,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2023,3,3]],"date-time":"2023-03-03T00:00:00Z","timestamp":1677801600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004488","name":"Croatian Science Foundation","doi-asserted-by":"publisher","award":["IP-2018-01-3298"],"award-info":[{"award-number":["IP-2018-01-3298"]}],"id":[{"id":"10.13039\/501100004488","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Density functional calculations SMD(chloroform)\/\/B3LYP\/6-311+G(2d,p) were employed in the computational study of 1,3-dipolar cycloadditions of azides with guanidine. The formation of two regioisomeric tetrazoles and their rearrangement to cyclic aziridines and open-chain guanidine products were modeled. The results suggest the feasibility of an uncatalyzed reaction under very drastic conditions since the thermodynamically preferred reaction path (a), which involves cycloaddition by binding the carbon atom from guanidine to the terminal azide nitrogen atom, and the guanidine imino nitrogen with the inner N atom from the azide, has an energy barrier higher than 50 kcal mol\u22121. The formation of the other regioisomeric tetrazole (imino nitrogen interacts with terminal N atom of azide) in direction (b) can be more favorable and proceed under milder conditions if alternative activation of the nitrogen molecule releases (e.g., photochemical activation), or deamination could be achieved because these processes have the highest barrier in the less favorable (b) branch of the mechanism. The introduction of substituents should favorably affect the cycloaddition reactivity of the azides, with the greatest effects expected for the benzyl and perfluorophenyl groups.<\/jats:p>","DOI":"10.3390\/molecules28052342","type":"journal-article","created":{"date-parts":[[2023,3,3]],"date-time":"2023-03-03T03:32:52Z","timestamp":1677814372000},"page":"2342","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Mechanistic DFT Study of 1,3-Dipolar Cycloadditions of Azides with Guanidine"],"prefix":"10.3390","volume":"28","author":[{"given":"Ivana","family":"Antol","sequence":"first","affiliation":[{"name":"Ru\u0111er Bo\u0161kovi\u0107 Institute, Bijeni\u010dka Cesta 54, HR-10002 Zagreb, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zoran","family":"Glasovac","sequence":"additional","affiliation":[{"name":"Ru\u0111er Bo\u0161kovi\u0107 Institute, Bijeni\u010dka Cesta 54, HR-10002 Zagreb, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1039-6569","authenticated-orcid":false,"given":"Davor","family":"Margeti\u0107","sequence":"additional","affiliation":[{"name":"Ru\u0111er Bo\u0161kovi\u0107 Institute, Bijeni\u010dka Cesta 54, HR-10002 Zagreb, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,3,3]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"5240","DOI":"10.1021\/cr100458v","article-title":"Advances in Determining the Absolute Proton Affinities of Neutral Organic Molecules in the Gas Phase and Their Interpretation: A Theoretical Account","volume":"112","author":"Vianello","year":"2012","journal-title":"Chem. 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